Pregnancy-induced hypertension Health Dictionary

Pregnancy-induced Hypertension: From 1 Different Sources


(PIH) raised blood pressure (>140/90 mmHg) developing in a woman during the second half of pregnancy. It usually resolves within six weeks of delivery and is associated with a better prognosis than *pre-eclampsia.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Hypertension

High arterial blood pressure... hypertension

Pulmonary Hypertension

In this condition, increased resistance to the blood ?ow through the LUNGS occurs. This is usually the result of lung disease, and the consequence is an increase in pulmonary artery pressure and in the pressure in the right side of the heart and in the veins bringing blood to the heart. Chronic BRONCHITIS or EMPHYSEMA commonly constrict the small arteries in the lungs, thus causing pulmonary HYPERTENSION. (See also EISENMENGER SYNDROME.)... pulmonary hypertension

Ectopic Pregnancy

An ectopic pregnancy most commonly develops in one of the FALLOPIAN TUBES. Occasionally it may occur in one of the OVARIES, and rarely in the uterine cervix or the abdominal cavity. Around one in 200 pregnant women have an ectopic gestation. As pregnancy proceeds, surrounding tissues may be damaged and, if serious bleeding happens, the woman may present as an ‘abdominal emergency’. A life-threatening condition, this needs urgent surgery. Most women recover satisfactorily and can have further pregnancies despite the removal of one Fallopian tube as a result of the ectopic gestation. Death is unusual. This disorder of pregnancy may occur because infection or a previous abdominal injury or operation may have damaged the normal descent of an ovum from the ovary to the womb. The ?rst symptoms usually appear during the ?rst two months of pregnancy, perhaps before the woman realises she is pregnant. Severe lower abdominal pain and vaginal bleeding are common presenting symptoms. Ultrasound can be used to diagnose the condition and laparoscopy can be used to remove the products of conception. (See PREGNANCY AND LABOUR.)... ectopic pregnancy

Portal Hypertension

Raised blood pressure in the PORTAL VEIN entering the LIVER. This results in increased pressure in the veins of the oesophagus and upper stomach and these grow in size to form varices – dilated tortuous veins. Sometimes these varices rupture, causing bleeding into the oesophagus. The raised pressure also causes ?uid to collect in the abdomen and form ASCITES. The commonest reason for portal hypertension is cirrhosis (?brosis) of the liver (see LIVER, DISEASES OF). THROMBOSIS in the portal vein may also be a cause. Treatment requires the cause to be tackled, but bleeding from ruptured vessels may be stopped by injecting a sclerosant or hardening solution into and around the veins. Sometimes a surgical shunt may be done to divert blood from the portal vein to another blood vessel.... portal hypertension

Tubal Pregnancy

Also known as ECTOPIC PREGNANCY. Implantation of the EMBRYO in one of the FALLOPIAN TUBES, rather than in the lining of the UTERUS. The patient usually complains of pain between six and ten weeks’ gestation and, if the Fallopian tube is not removed, there may be rupture with potentially life-threatening haemorrhage.... tubal pregnancy

Malignant Hypertension

Malignant hypertension has nothing to do with cancer; it derives its name from the fact that, if untreated, it runs a rapidly fatal course. (See HYPERTENSION.)... malignant hypertension

Pregnancy Tests

There are several tests for pregnancy (see PREGNANCY AND LABOUR) in its early stages, and these can be done on blood or urine; some of the urine tests may be carried out at home. Most tests are based on the detection of HUMAN CHORIONIC GONADOTROPHIN (HCG) in the woman’s urine. They are nearly 100 per cent accurate and may show positive as early as 30 days after the ?rst day of the last normal period.

The haemagglutination inhibition test This, and the subsequent tests to be mentioned, are known as immunological tests. They are based upon the e?ect of the urine from a pregnant woman upon the interaction of red blood cells, which have been sensitised to human gonadotrophin, and anti-gonadotrophin serum. They have the great practical advantage of being performed in a test-tube or even on a slide. Because of their ease and speed of performance, a result can be obtained in two hours.

Enzyme-linked immunosorbent assay (ELISA) This is the basis of many of the pregnancy-testing kits obtainable from pharmacies. It is a highly sensitive antibody test and can detect very low concentrations of human chorionic gonadotrophin. Positive results show up as early as ten days after fertilisation – namely, four days before the ?rst missed period.

Ultrasound The fetal sac can be detected by ULTRASOUND from ?ve weeks, and a fetal echo at around six or seven weeks (see also PRENATAL SCREENING OR DIAGNOSIS).... pregnancy tests

Pregnancy

The period from conception to birth. Pregnancy begins with the fertilization of an ovum (egg) and its implantation. The egg develops into the placenta and the embryo, which grows to form the fetus. Most eggs implant into the uterus. Very occasionally, an egg implants into an abnormal site, such as a fallopian tube, resulting in an ectopic pregnancy.

A normal pregnancy lasts around 40 weeks from the first day of the woman’s last menstrual period. It is divided into 3 stages (trimesters) of 3 months each. For the first 8 weeks of pregnancy, the developing baby is called an embryo; thereafter it is called a fetus.

In the 1st trimester the breasts start to swell and may become tender. Morning sickness is common. The baby’s major organs have developed by the end of this stage. During the 2nd trimester, the mother’s nipples enlarge and darken and weight rises rapidly. The baby is usually felt moving by 22 weeks. During the 3rd trimester, stretch marks and colostrum may appear, and Braxton Hick’s contractions may be felt. The baby’s head engages at about 36 weeks.

Common, minor health problems during pregnancy include constipation, haemorrhoids, heartburn, pica, swollen ankles, and varicose veins. Other common disorders include urinary tract infections, stress incontinence (see incontinence, urinary), and candidiasis.Complications of pregnancy and disorders that affect it include antepartum haemorrhage; diabetic pregnancy; miscarriage; polyhydramnios; pre-eclampsia; prematurity; and Rhesus incompatibility. (See also childbirth; fetal heart monitoring; pregnancy, multiple.)... pregnancy

Drinking Tea For Pregnancy

Women need to be careful both with what they eat and drink during pregnancy. Even if tea is generally recommended as an everyday beverage, most teas shouldn’t be drunk during pregnancy. Find out which teas you should and shouldn’t drink when you’re pregnant. Careful with teas for pregnancy There are various reasons why pregnant women should be careful with the type of tea they drink. Many are related to the caffeine content some tea varieties might have. Drinking tea with caffeine content might lead to birth defects or even unwanted miscarriages. Also, other tea varieties can lead to uterine contractions, or have properties that involve regulating menstruation. These can also lead to miscarriages. That doesn’t mean that, during pregnancy, women should completely stay away from teas. They just have to know what type of tea they can drink. Teas you can drink for pregnancy Rooibos tea is often recommended to pregnant women, as it doesn’t contain caffeine at all. It contains antioxidants, as well as a low level of tannins. Thanks to this, they are less likely to interfere with iron absorption and, therefore, cause anemia during and after pregnancy. It also helps with indigestion and may relieve nausea. Pregnant women can drink ginger tea or mint tea, which help with morning sickness, or chamomile tea to prevent insomnia. Also, nettle tea can be drunk during the second and third trimester of the pregnancy (not the first) only if it’s made from nettle leaves and not from the root. Raspberry leaf tea has many benefits related to pregnancy. First of all, if a woman wants to get pregnant, this tea will increase fertility, as well as strengthen the uterine wall and relax the muscle in the uterus. During pregnancy, it helps with leg cramps, morning sickness and diarrhea. Also, drinking this tea may lead to less artificial ruptures in the membranes, which lowers the chances of needing a caesarean delivery, as well as needing forceps or vacuum birth. Teas you shouldn’t drink for pregnancy Even if teas are usually considered to be good for our health, this isn’t the case. Women should be careful not to drink various types of tea for pregnancy. It is considered best for pregnant women not to drink teas that contain caffeine. Teas made from the Camellia sinensis plant (green tea, black tea, white tea, oolong tea) contain caffeine, so it is best to avoid them. Small amounts may be acceptable, however it can still be risky, as they might still lead to birth defects or miscarriages. Pregnant women should also be careful with herbal teas. The varieties they shouldn’t drink include devil’s claw, ephedra, fenugreek, gentian, ginseng, hawthorne, motherwort, red raspberry leaf, senna, shepherd’s purse, St. John’s wort, or yarrow. Teas for labor Partridge tea is recommended for pregnant women who are due to give birth. It is recommended to be drunk during the last 2-3 weeks of pregnancy. Partridge tea helps with relieving congestions of the uterus and ovaries. It can also be used as an antiseptic to treat vaginal infections. Plus, when it is combined with raspberry leaves, it can help even more during the last two weeks of pregnancy. Pregnant women should be careful even when it comes to the type of tea they drink. Some might be harmful, while others may help them a lot both during and after pregnancy. If you want to get pregnant, make sure you remember the accepted teas for pregnancy.... drinking tea for pregnancy

Drugs In Pregnancy

Unnecessary drugs during pregnancy should be avoided because of the adverse e?ect of some drugs on the fetus which have no harmful e?ect on the mother. Drugs may pass through the PLACENTA and damage the fetus because their pharmacological effects are enhanced as the enzyme systems responsible for their degradation are undeveloped in the fetus. Thus, if the drug can pass through the placenta, the pharmacological e?ect on the fetus may be great whilst that on the mother is minimal. WARFARIN may thus induce fetal and placental haemorrhage and the administration of THIAZIDES may produce THROMBOCYTOPENIA in the newborn. Many progestogens have androgenic side-effects and their administration to a mother for the purpose of preventing recurrent abortion may produce VIRILISATION of the female fetus. Tetracycline administered during the last trimester commonly stains the deciduous teeth of the child yellow.

The other dangers of administering drugs in pregnancy are the teratogenic effects (see TERATOGENESIS). It is understandable that a drug may interfere with a mechanism essential for growth and result in arrested or distorted development of the fetus and yet cause no disturbance in the adult, in whom these di?erentiation and organisation processes have ceased to be relevant. Thus the e?ect of a drug upon a fetus may di?er qualitatively as well as quantitatively from its e?ect on the mother. The susceptibility of the embryo will depend on the stage of development it has reached when the drug is given. The stage of early di?erentiation – that is, from the beginning of the third week to the end of the tenth week of pregnancy – is the time of greatest susceptibility. After this time the risk of congenital malformation from drug treatment is less, although the death of the fetus can occur at any time.... drugs in pregnancy

Essential (benign) Hypertension

See HYPERTENSION.... essential (benign) hypertension

Extrauterine Pregnancy

See ECTOPIC PREGNANCY.... extrauterine pregnancy

Fabricated And Induced Illness

See MUNCHAUSEN’S SYNDROME.... fabricated and induced illness

Pregnancy And Labour

Pregnancy The time when a woman carries a developing baby in her UTERUS. For the ?rst 12 weeks (the ?rst trimester) the baby is known as an EMBRYO, after which it is referred to as the FETUS.

Pregnancy lasts about 280 days and is calculated from the ?rst day of the last menstrual period – see MENSTRUATION. Pregnancy-testing kits rely on the presence of the hormone beta HUMAN CHORIONIC GONADOTROPHIN (b HCG) which is excreted in the woman’s urine as early as 30 days from the last menstrual period. The estimated date of delivery can be accurately estimated from the size of the developing fetus measured by ULTRASOUND (see also below) between seven and 24 weeks. ‘Term’ refers to the time that the baby is due; this can range from 38 weeks to 41 completed weeks.

Physical changes occur in early pregnancy – periods stop and the abdomen enlarges. The breasts swell, with the veins becoming prominent and the nipples darkening. About two in three women will have nausea with a few experiencing such severe vomiting as to require hospital admission for rehydration.

Antenatal care The aim of antenatal care is to ensure a safe outcome for both mother and child; it is provided by midwives (see MIDWIFE) and doctors. Formal antenatal care began in Edinburgh in the 1930s with the recognition that all aspects of pregnancy – normal and abnormal – warranted surveillance. Cooperation between general practitioners, midwives and obstetricians is now established, with pregnancies that are likely to progress normally being cared for in the community and only those needing special intervention being cared for in a hospital setting.

The initial visit (or booking) in the ?rst half of pregnancy will record the history of past events and the results of tests, with the aim of categorising the patients into normal or not. Screening tests including blood checks and ultrasound scans are a routine part of antenatal care. The ?rst ultrasound scan is done at about 11 weeks to date the pregnancy, with a further one done at 20 weeks – the anomaly scan – to assess the baby’s structure. Some obstetric units will check the growth of the baby with one further scan later in the pregnancy or, in the case of twin pregnancies (see below), many scans throughout. The routine blood tests include checks for ANAEMIA, DIABETES MELLITUS, sickle-cell disease and THALASSAEMIA, as well as for the blood group. Evidence of past infections is also looked for; tests for RUBELLA (German measles) and SYPHILIS are routine, whereas tests for human immunode?ciency virus (see AIDS/ HIV below) and HEPATITIS are being o?ered as optional, although there is compelling evidence that knowledge of the mother’s infection status is bene?cial to the baby.

Traditional antenatal care consists of regular appointments, initially every four weeks until 34 weeks, then fortnightly or weekly. At each visit the mother’s weight, urine and blood pressure are checked, and assessment of fetal growth and position is done by palpating the uterus. Around two-thirds of pregnancies and labours are normal: in the remainder, doctors and midwives need to increase the frequency of surveillance so as to prevent or deal with maternal and fetal problems.

Common complications of pregnancy

Some of the more common complications of pregnancy are listed below.

As well as early detection of medical complications, antenatal visits aim to be supportive and include emotional and educational care. Women with uncomplicated pregnancies are increasingly being managed by midwives and general practitioners in the community and only coming to the hospital doctors should they develop a problem. A small number will opt for a home delivery, but facilities for providing such a service are not always available in the UK.

Women requiring more intensive surveillance have their management targeted to the speci?c problems encountered. Cardiologists will see mothers-to-be with heart conditions, and those at risk of diabetes are cared for in designated clinics with specialist sta?. Those women needing more frequent surveillance than standard antenatal care can be looked after in maternity day centres. These typically include women with mildly raised blood pressure or those with small babies. Fetal medicine units have specialists who are highly skilled in ultrasound scanning and specialise in the diagnosis and management of abnormal babies still in the uterus. ECTOPIC PREGNANCY Chronic abdominal discomfort early in pregnancy may be caused by unruptured ectopic pregnancy, when, rarely, the fertilised OVUM starts developing in the Fallopian tube (see FALLOPIAN TUBES) instead of the uterus. The patient needs hospital treatment and LAPAROSCOPY. A ruptured ectopic pregnancy causes acute abdominal symptoms and collapse, and the woman will require urgent abdominal surgery. URINARY TRACT INFECTIONS These affect around 2 per cent of pregnant women and are detected by a laboratory test of a mid-stream specimen of urine. In pregnancy, symptoms of these infections do not necessarily resemble those experienced by non-pregnant women. As they can cause uterine irritability and possible premature labour (see below), it is important to ?nd and treat them appropriately. ANAEMIA is more prevalent in patients who are vegetarian or on a poor diet. Iron supplements are usually given to women who have low concentrations of HAEMOGLOBIN in their blood (less than 10.5 g/dl) or who are at risk of becoming low in iron, from bleeding, twin pregnancies and those with placenta previa (see below). ANTEPARTUM HAEMORRHAGE Early in pregnancy, vaginal bleedings may be due to a spontaneous or an incomplete therapeutic ABORTION. Bleeding from the genital tract between 24 completed weeks of pregnancy and the start of labour is called antepartum haemorrhage. The most common site is where the PLACENTA is attached to the wall of the uterus. If the placenta separates before delivery, bleeding occurs in the exposed ‘bed’. When the placenta is positioned in the upper part of the uterus it is called an abruption. PLACENTA PRAEVIA is sited in the lower part and blocks or partly blocks the cervix (neck of the womb); it can be identi?ed at about the 34th week. Ten per cent of episodes of antepartum bleeding are caused by placenta previa, and it may be associated with bleeding at delivery. This potentially serious complication is diagnosed by ultrasound scanning and may require a caesarean section (see below) at delivery. INCREASED BLOOD PRESSURE, associated with protein in the urine and swelling of the limbs, is part of a condition known as PRE-ECLAMPSIA. This occurs in the second half of pregnancy in about 1 in 10 women expecting their ?rst baby, and is mostly very mild and of no consequence to the pregnancy. However, some women can develop extremely high blood pressures which can adversely affect the fetus and cause epileptic-type seizures and bleeding disorders in the mother. This serious condition is called ECLAMPSIA. For this reason a pregnant woman with raised blood pressure or PROTEIN in her urine is carefully evaluated with blood tests, often in the maternity day assessment unit. The condition can be stopped by delivery of the baby, and this will be done if the mother’s or the fetus’s life is in danger. If the condition is milder, and the baby not mature enough for a safe delivery, then drugs can be used to control the blood pressure. MISCARRIAGE Also called spontaneous abortion, miscarriage is the loss of the fetus. There are several types:

threatened miscarriage is one in which some vaginal bleeding occurs, the uterus is enlarged, but the cervix remains closed and pregnancy usually proceeds.

inevitable miscarriage usually occurs before the 16th week and is typi?ed by extensive blood loss through an opened cervix and cramp-like abdominal pain; some products of conception are lost but the developing placental area (decidua) is retained and an operation may be necessary to clear the womb.

missed miscarriages, in which the embryo dies and is absorbed, but the decidua (placental area of uterine wall) remains and may cause abdominal discomfort and discharge of old blood.

THERAPEUTIC ABORTION is performed on more than 170,000 women annually in England and Wales. Sometimes the woman may not have arranged the procedure through the usual health-care channels, so that a doctor may see a patient with vaginal bleeding, abdominal discomfort or pain, and open cervix – symptoms which suggest that the decidua and a blood clot have been retained; these retained products will need to be removed by curettage.

Septic abortions are now much less common in Britain than before the Abortion Act (1967) permitted abortion in speci?ed circumstances. The cause is the passage of infective organisms from the vagina into the uterus, with Escherichia coli and Streptococcus faecalis the most common pathogenic agents. The woman has abdominal pain, heavy bleeding, usually fever and sometimes she is in shock. The cause is usually an incomplete abortion or one induced in unsterile circumstances. Antibiotics and curettage are the treatment. INTRAUTERINE GROWTH RETARDATION describes a slowing of the baby’s growth. This can be diagnosed by ultrasound scanning, although there is a considerable margin of error in estimates of fetal weight. Trends in growth are favoured over one-o? scan results alone. GESTATIONAL DIABETES is a condition that is more common in women who are overweight or have a family member with diabetes. If high concentrations of blood sugar are found, e?orts are made to correct it as the babies can become very fat (macrosomia), making delivery more di?cult. A low-sugar diet is usually enough to control the blood concentration of sugars; however some women need small doses of INSULIN to achieve control. FETAL ABNORMALITIES can be detected before birth using ultrasound. Some of these defects are obvious, such as the absence of kidneys, a condition incompatible with life outside the womb. These women can be o?ered a termination of their pregnancy. However, more commonly, the pattern of problems can only hint at an abnormality and closer examination is needed, particularly in the diagnosis of chromosomal deformities such as DOWN’S (DOWN) SYNDROME (trisomy 21 or presence of three 21 chromosomes instead of two).

Chromosomal abnormalities can be de?nitively diagnosed only by cell sampling such as amniocentesis (obtaining amniotic ?uid – see AMNION – from around the baby) done at 15 weeks onwards, and chorionic villus sampling (sampling a small part of the placenta) – another technique which can be done from 12 weeks onwards. Both have a small risk of miscarriage associated with them; consequently, they are con?ned to women at higher risk of having an abnormal fetus.

Biochemical markers present in the pregnant woman’s blood at di?erent stages of pregnancy may have undergone changes in those carrying an abnormal fetus. The ?rst such marker to be routinely used was a high concentration of alpha-fetol protein in babies with SPINA BIFIDA (defects in the covering of the spinal cord). Fuller research has identi?ed a range of diagnostic markers which are useful, and, in conjunction with other factors such as age, ethnic group and ultrasound ?ndings, can provide a predictive guide to the obstetrician – in consultation with the woman – as to whether or not to proceed to an invasive test. These tests include pregnancy-associated plasma protein assessed from a blood sample taken at 12 weeks and four blood tests at 15–22 weeks – alphafetol protein, beta human chorionic gonadotrophin, unconjugated oestriol and inhibin A. Ultrasound itself can reveal physical ?ndings in the fetus, which can be more common in certain abnormalities. Swelling in the neck region of an embryo in early pregnancy (increased nuchal thickness) has good predictive value on its own, although its accuracy is improved in combination with the biochemical markers. The e?ectiveness of prenatal diagnosis is rapidly evolving, the aim being to make the diagnosis as early in the pregnancy as possible to help the parents make more informed choices. MULTIPLE PREGNANCIES In the UK, one in 95 deliveries is of twins, while the prevalence of triplets is one in 10,000 and quadruplets around one in 500,000. Racial variations occur, with African women having a prevalence rate of one in 30 deliveries for twins and Japanese women a much lower rate than the UK ?gure. Multiple pregnancies occur more often in older women, and in the UK the prevalence of fertility treatments, many of these being given to older women, has raised the incidence. There is now an o?cial limit of three eggs being transferred to a woman undergoing ASSISTED CONCEPTION (gamete intrafallopian transfer, or GIFT).

Multiple pregnancies are now usually diagnosed as a result of routine ultrasound scans between 16 and 20 weeks of pregnancy. The increased size of the uterus results in the mother having more or worse pregnancy-related conditions such as nausea, abdominal discomfort, backache and varicose veins. Some congenital abnormalities in the fetus occur more frequently in twins: NEURAL TUBE defects, abnormalities of the heart and the incidence of TURNER’S SYNDROME and KLINEFELTER’S SYNDROME are examples. Such abnormalities may be detected by ultrasound scans or amniocentesis. High maternal blood pressure and anaemia are commoner in women with multiple pregnancies (see above).

The growth rates of multiple fetuses vary, but the di?erence between them and single fetuses are not that great until the later stages of pregnancy. Preterm labour is commoner in multiple pregnancies: the median length of pregnancy is 40 weeks for singletons, 37 for twins and 33 for triplets. Low birth-weights are usually the result of early delivery rather than abnormalities in growth rates. Women with multiple pregnancies require more frequent and vigilant antenatal assessments, with their carers being alert to the signs of preterm labour occurring. CEPHALOPELVIC DISPROPORTION Disparity between the size of the fetus and the mother’s pelvis is not common in the UK but is a signi?cant problem in the developing world. Disparity is classi?ed as absolute, when there is no possibility of delivery, and relative, when the baby is large but delivery (usually after a dif?cult labour) is possible. Causes of absolute disparity include: a large baby – heavier than 5 kg at birth; fetal HYDROCEPHALUS; and an abnormal maternal pelvis. The latter may be congenital, the result of trauma or a contraction in pelvic size because of OSTEOMALACIA early in life. Disproportion should be suspected if in late pregnancy the fetal head has not ‘engaged’ in the pelvis. Sometimes a closely supervised ‘trial of labour’ may result in a successful, if prolonged, delivery. Otherwise a caesarean section (see below) is necessary. UNUSUAL POSITIONS AND PRESENTATIONS OF THE BABY In most pregnant women the baby ?ts into the maternal pelvis head-?rst in what is called the occipito-anterior position, with the baby’s face pointing towards the back of the pelvis. Sometimes, however, the head may face the other way, or enter the pelvis transversely – or, rarely, the baby’s neck is ?exed backwards with the brow or face presenting to the neck of the womb. Some malpositions will correct naturally; others can be manipulated abdominally during pregnancy to a better position. If, however, the mother starts labour with the baby’s head badly positioned or with the buttocks instead of the head presenting (breech position), the labour will usually be longer and more di?cult and may require intervention using special obstetric forceps to assist in extracting the baby. If progress is poor and the fetus distressed, caesarean section may be necessary. HIV INFECTION Pregnant women who are HIV positive (see HIV; AIDS/HIV) should be taking antiviral drugs in the ?nal four to ?ve months of pregnancy, so as to reduce the risk of infecting the baby in utero and during birth by around 50 per cent. Additional antiviral treatment is given before delivery; the infection risk to the baby can be further reduced – by about 40 per cent – if delivery is by caesarean section. The mother may prefer to have the baby normally, in which case great care should be taken not to damage the baby’s skin during delivery. The infection risk to the baby is even further reduced if it is not breast fed. If all preventive precautions are taken, the overall risk of the infant becoming infected is cut to under 5 per cent.

Premature birth This is a birth that takes place before the end of the normal period of gestation, usually before 37 weeks. In practice, however, it is de?ned as a birth that takes place when the baby weighs less than 2·5 kilograms (5••• pounds). Between 5 and 10 per cent of babies are born prematurely, and in around 40 per cent of premature births the cause is unknown. Pre-eclampsia is the most common known cause; others include hypertension, chronic kidney disease, heart disease and diabetes mellitus. Multiple pregnancy is another cause. In the vast majority of cases the aim of management is to prolong the pregnancy and so improve the outlook for the unborn child. This consists essentially of rest in bed and sedation, but there are now several drugs, such as RITODRINE, that may be used to suppress the activity of the uterus and so help to delay premature labour. Prematurity was once a prime cause of infant mortality but modern medical care has greatly improved survival rates in developing countries.

Labour Also known by the traditional terms parturition, childbirth or delivery, this is the process by which the baby and subsequently the placenta are expelled from the mother’s body. The onset of labour is often preceded by a ‘show’ – the loss of the mucus and blood plug from the cervix, or neck of the womb; this passes down the vagina to the exterior. The time before the beginning of labour is called the ‘latent phase’ and characteristically lasts 24 hours or more in a ?rst pregnancy. Labour itself is de?ned by regular, painful contractions which cause dilation of the neck of the womb and descent of the fetal head. ‘Breaking of the waters’ is the loss of amniotic ?uid vaginally and can occur any time in the delivery process.

Labour itself is divided into three stages: the ?rst is from the onset of labour to full (10 cm) dilation of the neck of the womb. This stage varies in length, ideally taking no more than one hour per centimetre of dilation. Progress is monitored by regular vaginal examinations, usually every four hours. Fetal well-being is observed by intermittent or continuous monitoring of the fetal heart rate in relation to the timing and frequency of the contractions. The print-out is called a cardiotocograph. Abnormalities of the fetal heart rate may suggest fetal distress and may warrant intervention. In women having their ?rst baby (primigravidae), the common cause of a slow labour is uncoordinated contractions which can be overcome by giving either of the drugs PROSTAGLANDIN or OXYTOCIN, which provoke contractions of the uterine muscle, by an intravenous drip. Labours which progress slowly or not at all may be due to abnormal positioning of the fetus or too large a fetus, when prostaglandin or oxytocin is used much more cautiously.

The second stage of labour is from full cervical dilation to the delivery of the baby. At this stage the mother often experiences an irresistible urge to push the baby out, and a combination of strong coordinated uterine contractions and maternal e?ort gradually moves the baby down the birth canal. This stage usually lasts under an hour but can take longer. Delay, exhaustion of the mother or distress of the fetus may necessitate intervention by the midwife or doctor. This may mean enlarging the vaginal opening with an EPISIOTOMY (cutting of the perineal outlet – see below) or assisting the delivery with specially designed obstetric forceps or a vacuum extractor (ventouse). If the cervix is not completely dilated or open and the head not descended, then an emergency caesarean section may need to be done to deliver the baby. This procedure involves delivering the baby and placenta through an incision in the mother’s abdomen. It is sometimes necessary to deliver by planned or elective caesarean section: for example, if the placenta is low in the uterus – called placenta praevia – making a vaginal delivery dangerous.

The third stage occurs when the placenta (or afterbirth) is delivered, which is usually about 10–20 minutes after the baby. An injection of ergometrine and oxytocin is often given to women to prevent bleeding.

Pain relief in labour varies according to the mother’s needs. For uncomplicated labours, massage, reassurance by a birth attendant, and a warm bath and mobilisation may be enough for some women. However, some labours are painful, particularly if the woman is tired or anxious or is having her ?rst baby. In these cases other forms of analgesia are available, ranging from inhalation of NITROUS OXIDE GAS, injection of PETHIDINE HYDROCHLORIDE or similar narcotic, and regional local anaesthetic (see ANAESTHESIA).

Once a woman has delivered, care continues to ensure her and the baby’s safety. The midwives are involved in checking that the uterus returns to its normal size and that there is no infection or heavy bleeding, as well as caring for stitches if needed. The normal blood loss after birth is called lochia and generally is light, lasting up to six weeks. Midwives o?er support with breast feeding and care of the infant and will visit the parents at home routinely for up to two weeks.

Some complications of labour All operative deliveries in the UK are now done in hospitals, and are performed if a spontaneous birth is expected to pose a bigger risk to the mother or her child than a specialist-assisted one. Operative deliveries include caesarean section, forceps-assisted deliveries and those in which vacuum extraction (ventouse) is used. CAESAREAN SECTION Absolute indications for this procedure, which is used to deliver over 15 per cent of babies in Britain, are cephalopelvic disproportion and extensive placenta praevia, both discussed above. Otherwise the decision to undertake caesarean section depends on the clinical judgement of the specialist and the views of the mother. The rise in the proportion of this type of intervention (from 5 per cent in the 1930s to its present level of over 23 per cent

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of the 600,000 or so annual deliveries in England) has been put down to defensive medicine

– namely, the doctor’s fear of litigation (initiated often because the parents believe that the baby’s health has suffered because the mother had an avoidably di?cult ‘natural’ labour). In Britain, over 60 per cent of women who have had a caesarean section try a vaginal delivery in a succeeding pregnancy, with about two-thirds of these being successful. Indications for the operation include:

absolute and relative cephalopelvic disproportion.

placenta previa.

fetal distress.

prolapsed umbilical cord – this endangers the viability of the fetus because the vital supply of oxygen and nutrients is interrupted.

malpresentation of the fetus such as breech or transverse lie in the womb.

unsatisfactory previous pregnancies or deliveries.

a request from the mother.

Caesarean sections are usually performed using regional block anaesthesia induced by a spinal or epidural injection. This results in loss of feeling in the lower part of the body; the mother is conscious and the baby not exposed to potential risks from volatile anaesthetic gases inhaled by the mother during general anaesthesia. Post-operative complications are higher with general anaesthesia, but maternal anxiety and the likelihood that the operation might be complicated and di?cult are indications for using it. A general anaesthetic may also be required for an acute obstetric emergency. At operation the mother’s lower abdomen is opened and then her uterus opened slowly with a transverse incision and the baby carefully extracted. A transverse incision is used in preference to the traditional vertical one as it enables the woman to have a vaginal delivery in any future pregnancy with a much smaller risk of uterine rupture. Women are usually allowed to get up within 24 hours and are discharged after four or ?ve days. FORCEPS AND VENTOUSE DELIVERIES Obstetric forceps are made in several forms, but all are basically a pair of curved blades shaped so that they can obtain a purchase on the baby’s head, thus enabling the operator to apply traction and (usually) speed up delivery. (Sometimes they are used to slow down progress of the head.) A ventouse or vacuum extractor comprises an egg-cup-shaped metal or plastic head, ranging from 40 to 60 mm in diameter with a hollow tube attached through which air is extracted by a foot-operated vacuum pump. The instrument is placed on the descending head, creating a negative pressure on the skin of the scalp and enabling the operator to pull the head down. In mainland Europe, vacuum extraction is generally preferred to forceps for assisting natural deliveries, being used in around 5 per cent of all deliveries. Forceps have a greater risk of causing damage to the baby’s scalp and brain than vacuum extraction, although properly used, both types should not cause any serious damage to the baby.

Episiotomy Normal and assisted deliveries put the tissues of the genital tract under strain. The PERINEUM is less elastic than the vagina and, if it seems to be splitting as the baby’s head

moves down the birth canal, it may be necessary to cut the perineal tissue – a procedure called an episiotomy – to limit damage. This is a simple operation done under local anaesthetic. It should be done only if there is a speci?c indication; these include:

to hasten the second stage of labour if the fetus is distressed.

to facilitate the use of forceps or vacuum extractor.

to enlarge a perineum that is restricted because of unyielding tissue, perhaps because of a scar from a previous labour. Midwives as well as obstetricians are trained

to undertake and repair (with sutures) episiotomies.

(For organisations which o?er advice and information on various aspects of childbirth, including eclampsia, breast feeding and multiple births, see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELF-HELP.)... pregnancy and labour

Pregnancy Calendar - Week 4 Of Your Pregnancy

4 weeks pregnancy

"Pregnancy calendar" at 4th week: A miracle begins! Your baby, now consisting of a cell stack, is clinging to the walls of your uterus and starting to grow rapidly. Early pregnancy in this period, for example, nausea in pregnancy is extremely normal. Birth is a beautiful yet remote dream.

Your baby in 4 weeks pregnancy

Your baby is a seed of poppy seeds. By the end of the week your baby will be about 1 mm long. Once the fertilized egg is placed on the side of your uterus, it divides into cell layers and becomes an embryo from official care. These cells turn into the body of your baby during pregnancy, forming the nervous system, skeleton, muscles and organs.

Support system in formation

The disc-like organ, which connects your body systems to the baby's systems, begins to form and attaches to the uterine wall where the egg is placed. The umbilical cord comes out of one of the placenta. Amniotic fluid, which will stretch your baby during pregnancy, has begun to form in a circumscribing membrane sac.

Your 4th week pregnancy

As the fertilized egg gets into your uterus, you may experience some bleeding. This is known as implantation hemorrhage and is completely normal.

The results came

Thanks to the brand-new placenta-attacked hCG hormone and a pregnancy test at home after the first period you missed, you will get a positive result, but false negative results can also be seen. This hormone is the greatest cause of nausea or morning sickness that many pregnant women experience in the first three months. If you are not pregnant, but your pregnancy test at home is negative, you may need a doctor.... pregnancy calendar - week 4 of your pregnancy

Pregnancy Calendar - Week 5 Of Your Pregnancy

5-week pregnancy

"Pregnancy calendar" at week 5: Your baby's brain is developing. You may feel fears about pregnancy and birth during this period. These emotional fluctuations are normal, do not worry at all!

Baby for 5 weeks gestation

Your baby, between 1 and 2.5 mm, is a small orange seed.

Installation ready

The placenta and the umbilical cord that begins to form have begun to work to transfer the necessary nutrients from your body to the body of the baby. Oxygen, amino acids, fats and sugars all play a critical role in a healthy development.

Some basics

Some of Baby's cells turn into a nerve pathway that will form the backbone and brain. An incorrectly formed nerve pathway can lead to a complication called "discrete spine", a condition in which the spinal cord is not completely closed. Your best weapon against spinal cord birth defects is to take at least 400 micrograms of folic acid every day.

Heart start

The heart is now a single tube with a few irregular shots. With each passing week these shots will become more regular.

Your 5th week pregnancy

Emotional ocean

You may be very happy because you are pregnant, worried about everything being normal, fearful about birth, or not being sure of yourself as a mothers of mothers. Do not worry about it! All of these feelings are completely normal. By weekly calculation of pregnancy and birth calculation, keep your head busy dreaming about the birth of your baby.

Careful maintenance

At this stage of the pregnancy period, menstrual cramps and back pain are common. Take a break by taking a warm bath, listening to soothing music or taking a nap. Watch your food and if you have not done so, stop smoking, drinking alcohol or taking medication. All of this is harmful to your baby.... pregnancy calendar - week 5 of your pregnancy

Abortion, Induced

Medically induced termination of pregnancy. Abortion may be performed if continuation of the pregnancy would risk the woman’s life, if the mental or physical health of the woman or her existing children is at risk, or if there is a substantial risk of handicap to the baby.

Depending on the stage of pregnancy, termination may be induced by using drugs or by the surgical technique of vacuum suction curettage, under either a general or local anaesthetic, during which the fetal and placental tissues are removed.

Complications are rare.... abortion, induced

Molar Pregnancy

A pregnancy in which a tumour develops from the placental tissue and the embryo does not develop normally. A molar pregnancy may be noncancerous (a hydatidiform mole) or may invade the wall of the

uterus (an invasive mole). A molar pregnancy that becomes cancerous is called a choriocarcinoma.

If the dead embryo and placenta are not expelled from the uterus after a miscarriage, the dead tissue is called a carneous mole.... molar pregnancy

Diabetic Pregnancy

Pregnancy in a woman with pre-existing diabetes mellitus or in a woman who develops diabetes during pregnancy. The latter is known as gestational diabetes. Women with established diabetes mellitus can have a normal pregnancy provided that the diabetes is controlled well. Poor control of blood glucose during the pregnancy may affect the baby’s growth or increase the risk of complications during pregnancy.

Gestational diabetes is usually detected in the second half of pregnancy.

The mother does not produce enough insulin to keep blood glucose levels normal.

True gestational diabetes disappears with the delivery of the baby but is associated with an increased risk of developing type 2 diabetes in later life.... diabetic pregnancy

Multiple Pregnancy

See pregnancy, multiple.... multiple pregnancy

Noise-induced Hearing Loss

Hearing loss caused by prolonged exposure to excessive noise or by brief exposure to intensely loud noise.

Exposure to a sudden, very loud noise, usually above 130 decibels, can cause immediate and permanent damage to hearing. Normally, muscles in the middle ear respond to loud noise by altering the position of the ossicles (the chain of bones that pass vibrations to the inner ear), thus damping down the intensity of the noise. If these protective reflexes have no time to respond, the full force of the vibrations is carried to the inner ear, severely damaging the delicate hair cells in the cochlea. Occasionally, loud noises can rupture the eardrum.

More commonly, noise damage occurs over a period of time by prolonged exposure to lower levels of noise. Any noise above 85–90 decibels may cause damage, with gradual destruction of the hair cells of the cochlea, leading to permanent hearing loss. Prolonged exposure to loud noise leads initially to a loss of the ability to hear certain high tones. Later, deafness extends to all high frequencies, and the perception of speech is impaired. Eventually, lower tones are also affected.

Sounds at 85–90 decibels or above may cause pain and temporary deafness. Prolonged tinnitus (ringing or buzzing in

the ears) occurring after a noise has ceased is an indication that some damage has probably occurred.... noise-induced hearing loss

Pregnancy, False

An uncommon psychological disorder, medically known as pseudocyesis, in which a woman has physical signs of pregnancy, including morning sickness, amenorrhoea (absence of periods), enlarged breasts, and abdominal swelling, but is not pregnant. The woman is convinced that she is pregnant. Treatment for false pregnancy

may involve counselling or psychotherapy. (See also conversion disorder.)... pregnancy, false

Pregnancy, Multiple

The presence of more than 1 fetus in the uterus. Multiple pregnancy can occur if 2 or more ova (eggs) are fertilized at the same time, or if a single fertilized egg divides early in development.

Twins occur in about 1 in 80 pregnancies, triplets in about 1 in 8,000, and quadruplets in about 1 in 73,000.

Multiple pregnancies are more common in women who are treated with fertility drugs or if a number of fertilized ova are implanted during in vitro fertilization.... pregnancy, multiple

Termination Of Pregnancy

See abortion, induced.... termination of pregnancy

Toxaemia Of Pregnancy

See preeclampsia.... toxaemia of pregnancy

Pregnancy, Drugs In

Certain drugs taken during pregnancy may pass to the fetus through the placenta or interfere with fetal development. This may lead to birth defects. Although relatively few drugs have been proved to cause harm to a developing baby, no drug should be considered completely safe, especially during early pregnancy. For this reason, pregnant women should seek advice from their doctor or pharmacist before taking any drug, including over-thecounter preparations.

Problems may also be caused in a developing baby if a pregnant woman drinks alcohol, smokes (see tobaccosmoking), or takes drugs of abuse. The babies of women who use heroin during pregnancy tend to have a low birthweight and a higher death rate than normal during the first few weeks of life. Babies of women who abuse drugs intravenously are at high risk of HIV infection.... pregnancy, drugs in

Vomiting In Pregnancy

Nausea and vomiting in early pregnancy are common and are most likely to be caused by changes in the hormone levels. Vomiting occurs most frequently in the morning, but it may occur at any time. It is sometimes precipitated by stress, travelling, or food.

In rare cases, the vomiting becomes severe and prolonged. This can cause dehydration, nutritional deficiency, alterations in blood acidity, and weight loss. Immediate hospital admission is then required to replace lost fluids and chemicals by intravenous infusion, to rule out any serious underlying disorder, and to control the vomiting.... vomiting in pregnancy

Acute Fatty Liver Of Pregnancy

a rare and life-threatening complication of pregnancy that usually presents in the third trimester with symptoms of nausea, vomiting, malaise, and abdominal pain. Liver function tests are abnormal and the features of *pre-eclampsia and often *HELLP syndrome are present. *Hepatic encephalopathy, *disseminated intravascular coagulation, and renal failure may develop, and the condition is associated with a high maternal and fetal mortality. Treatment involves a multidisciplinary approach, usually in an intensive care unit.... acute fatty liver of pregnancy

Benign Intracranial Hypertension

see idiopathic intracranial hypertension.... benign intracranial hypertension

False Pregnancy

see pseudocyesis.... false pregnancy

Idiopathic Intracranial Hypertension

(benign intracranial hypertension, pseudotumour cerebri) a syndrome of raised pressure within the skull in the absence of a clear structural cause, such as a tumour. Although the cause is not certain, proposed mechanisms include impaired reabsorption of cerebrospinal fluid or venous outflow from the brain. The symptoms include headache, vomiting, double vision, and *papilloedema. The diagnosis is made by finding a high opening pressure at *lumbar puncture in the absence of a causative structural abnormality on brain imaging. It can improve spontaneously but drug therapy or neurosurgical treatment may be required to protect the patient’s vision.... idiopathic intracranial hypertension

Induced Abortion

see abortion.... induced abortion

Ocular Hypertension

(OHT) a constantly raised intraocular pressure (greater than 21 mmHg by Goldmann applanation *tonometry) registered on two or more occasions in one or both eyes with the absence of evidence of optic nerve damage or visual field defect. Intraocular pressure increases slowly with age and OHT can increase the risk of developing glaucoma. It is treated with eye drops and surgery if indicated.... ocular hypertension

Phantom Pregnancy

see pseudocyesis.... phantom pregnancy

Polymorphic Eruption Of Pregnancy

(PEP) intensely itchy papules and weals on the abdomen (except the umbilicus), upper limbs, and buttocks, usually within the *striae gravidarum; it is also known as PUPPP (pruritic urticarial papules and plaques of pregnancy). It occurs in 1 in 250 first pregnancies late in the third trimester. This condition is harmless to mother and baby, but can be very annoying. It lasts an average of 6 weeks and resolves spontaneously 1–2 weeks after delivery. The most severe itching normally lasts for no more than a week.... polymorphic eruption of pregnancy

Post-term Pregnancy

a pregnancy that has gone beyond 42 weeks gestation or 294 days from the first date of the last menstrual period.... post-term pregnancy

Pregnancy Epulis

(pregnancy tumour, granuloma gravidarum) a benign growth on the gums caused by inflammation of the gingivae during pregnancy. This type of *epulis may not need any specific treatment as it often shrinks post-partum.... pregnancy epulis

Pregnancy Of Unknown Location

(PUL) a positive pregnancy test when no fetus can be seen on an ultrasound scan, which is due to a very early ongoing pregnancy, an early failing pregnancy, or an ectopic pregnancy not located on scan.... pregnancy of unknown location

Renovascular Hypertension

disease affecting the arterial supply to the kidneys, leading to ischaemia and resultant stimulation of the renin-*angiotensin-aldosterone axis. In the major vessels, the most common cause is atheromatous plaque disease. Other causes are fibromuscular dysplasia and *Takayasu’s disease.... renovascular hypertension

Pregnancy Test

any of several methods used to demonstrate whether or not a woman is pregnant. Most pregnancy tests are based on the detection of a hormone, *human chorionic gonadotrophin (hCG), in the urine. The sample of urine is mixed with serum containing antibodies to hCG and marker particles (sheep red cells or latex particles) coated with hCG. In the absence of pregnancy, the antibodies will cause *agglutination of the marker particles. If the urine is from a pregnant woman, the antibodies will be absorbed and no agglutination will occur. These tests may be positive for pregnancy as early as 30 days after the date of the last normal period and are 98% accurate. Newer tests using *monoclonal antibodies (beta hCG) are more easily interpreted. When carried out on serum rather than urine, these tests give even earlier positive results.... pregnancy test



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