Obstetrics Health Dictionary

A two-pronged instrument with pointed ends, for the measurement of diameters, such as that of the pelvis in obstetrics.... calliper

The branch of medicine dealing with the female pelvic and urogenital organs, in both the normal and diseased states. It encompasses aspects of CONTRACEPTION, ABORTION, and in vitro fertilisation or IVF (see under ASSISTED CONCEPTION). Covering the full age range, it is closely related to OBSTETRICS, while involving aspects of both surgery and psychiatry.... gynaecology

(Fr.) Tul.

Family: Hypocreaceae.

Habitat: A fungous parasite on a number of grasses particularly in rye, cultivated in the Nilgiris and at Chakrohi farm in Jammu.

English: Ergot of Rye. Fungus of Rye.

Ayurvedic: Annamaya, Sraavikaa.

Unani: Argot.

Siddha/Tamil: Ergot.

Action: Uterine stimulant. Oxy- tocic, abortifacient, parturient, vasoconstrictor, haemostatic. Used in obstetrics (difficult childbirth, for exciting uterine contractions in the final stages of parturition). Also used after abortion for removal of the placenta. It is no more employed in internal haemorrhages, as it has been found to raise blood pressure in pulmonary and cerebral haemorrhage. Included among unapproved herbs by German Commission E.

The fungus gave indole alkaloids. The ergometrine or ergonovine group includes ergometrine and ergometri- nine. The ergotamine group includes ergotamine and ergotaminine. The er- gotoxine group includes ergocristine, ergocristinine, ergocryptine, ergo- cryptinine, ergocornine and ergo- corninine. The fungus also contains histamine, tyramine and other amines, sterols and acetylcholine.

The alkaloids of ergot are being used independently (not as a herbal medicine). Ergotamine is used to relieve migrainous headaches as it is a vasoconstrictor and has antisero- tonin activity. Ergometrine is used after childbirth in the third stage of labour and for post-partum haemorrhage, as it is a powerful uterine stimulant, particularly of the puerperal uterus. (Both the constituents are used under medical supervision). Er- gocornine significantly inhibited the development of induced mammary tumours in rats. The derivatives of ergot alkaloids are known to have suppressing effect on human breast cancer in initial stages. This activity is linked to prolactin inhibitory action.

The extract is toxic at 1.0-3.9 g, ergot alkaloids at 1 g in adults, 12 mg in infants. (Francis Brinker).

Dosage: Whole plant—10-30 ml infusion. (CCRAS.)... claviceps purpurea

Psychology is the scienti?c study of behaviour. It may be applied in various settings including education, industry and health care. Clinical psychology is concerned with the practical application of research ?ndings in the ?elds of physical and mental health. Training in clinical psychology involves a degree in psychology followed by postgraduate training. Clinical psychologists are speci?cally skilled in applying theoretical models and objective methods of observation and measurement, and in therapeutic interventions aimed at changing patients’ dysfunctional behaviour, including thoughts and feelings as well as actions. Dysfunctional behaviour is explained in terms of normal processes and modi?ed by applying principles of normal learning, adaption and social interaction.

Clinical psychologists are involved in health care in the following ways: (1) Assessment of thoughts, emotions and behaviour using standardised methods. (2) Treatment based on theoretical models and scienti?c evidence about behaviour change. Behaviour change is considered when it contributes to physical, psychological or social functioning. (3) Consultation with other health-care professionals about problems concerning emotions, thinking and behaviour. (4) Research on a wide variety of topics including the relationship between stress, psychological functioning and disease; the aetiology of problem behaviours; methods and theories of behaviour change. (5) Teaching other professionals about normal and dysfunctional behaviour, emotions and functioning.

Clinical psychologists may specialise in work in particular branches of patient care, including surgery, psychiatry, geriatrics, paediatrics, mental handicap, obstetrics and gynaecology, cardiology, neurology, general practice and physical rehabilitation. Whilst the focus of their work is frequently the patient, at times it may encompass the behaviour of the health-care professionals.... clinical psychology

That branch of medicine involved in the treatment of injuries, deformities or individual diseases by operation or manipulation. It incorporates: general surgery; specialised techniques such as CRYOSURGERY, MICROSURGERY, MINIMALLY INVASIVE SURGERY (MIS), or minimal access (keyhole) surgery, and stereotactic sugery (see STEREOTAXIS); and surgery associated with the main specialties, especially cardiothoracic surgery, gastroenterology, GYNAECOLOGY, NEUROLOGY, OBSTETRICS, ONCOLOGY, OPHTHALMOLOGY, ORTHOPAEDICS, TRANSPLANTATION surgery, RECONSTRUCTIVE (PLASTIC) SURGERY, and UROLOGY. Remotely controlled surgery using televisual and robotic techniques is also being developed.

It takes up to 15 years to train a surgeon from the time at which he or she enters medical school; after graduating as a doctor a surgeon has to pass a comprehensive two-stage examination to become a fellow of one of the ?ve recognised colleges of surgeons in the UK and Ireland.

Surgery is carried out in specially designed operating theatres. Whereas it used to necessitate days and sometimes weeks of inpatient hospital care, many patients are now treated as day patients, often under local anaesthesia, being admitted in the morning and discharged later in the day.

More complex surgery, such as transplantation and neurosurgery, usually necessitates patients being nursed post-operatively in high-dependency units (see INTENSIVE THERAPY UNIT (ITU)) before being transferred to ordinary recovery wards. Successful surgery requires close co-operation between surgeons, physicians and radiologists as well as anaesthetists (see ANAESTHESIA), whose sophisticated techniques enable surgeons to undertake long and complex operations that were unthinkable 30 or more years ago. Surgical treatment of cancers is usually done in collaboration with oncologists. Successful surgery is also dependent on the skills of supporting sta? comprising nurses and operating-theatre technicians and the availability of up-to-date facilities.... surgery

The name given to an operation in OBSTETRICS which consists in turning the FETUS in the UTERUS where the fetus is lying in an abnormal position which may make eventual delivery di?cult. In particular, version (which can take place spontaneously) may be done on a fetus between the 34th and 37th weeks of pregnancy when its buttocks rather than its head are positioned at the cervical end of the uterus. The procedure carries a small risk of precipitating premature labour, and it is not always successful, in which case a breech delivery is attempted or, in di?cult cases, a CAESAREAN SECTION is performed. (See also PREGNANCY AND LABOUR.)... version

A general practitioner (‘family doctor’; ‘family practitioner’) is a doctor working in primary care, acting as the ?rst port of professional contact for most patients in the NHS. There are approximately 35,000 GPs in the UK and their services are accessed by registering with a GP practice – usually called a surgery or health centre. Patients should be able to see a GP within 48 hours, and practices have systems to try to ensure that urgent problems are dealt with immediately. GPs generally have few diagnostic or treatment facilities themselves, but can use local hospital diagnostic services (X-rays, blood analysis, etc.) and can refer or admit their patients to hospital, where they come under the supervision of a CONSULTANT. GPs can prescribe nearly all available medicines directly to their patients, so that they treat 90 per cent of illnesses without involving specialist or hospital services.

Most GPs work in groups of self-employed individuals, who contract their services to the local Primary Care Trust (PCT) – see below. Those in full partnership are called principals, but an increasing number now work as non-principals – that is, they are employees rather than partners in a practice. Alternatively, they might be salaried employees of a PCT. The average number of patients looked after by a full-time GP is 1,800 and the average duration of consultation about 10 minutes. GPs need to be able to deal with all common medical conditions and be able to recognise conditions that require specialist help, especially those requiring urgent action.

Until the new General Medical Services Contract was introduced in 2004, GPs had to take individual responsibility for providing ‘all necessary medical services’ at all times to their patient list. Now, practices rather than individuals share this responsibility. Moreover, the contract now applies only to the hours between

8.00 a.m. and 6.30 p.m., Mondays to Fridays; out-of-hours primary care has become the responsibility of PCTs. GPs still have an obligation to visit patients at home on weekdays in case of medical need, but home-visiting as a proportion of GP work has declined steadily since the NHS began. By contrast, the amount of time spent attending to preventive care and organisational issues has steadily increased. The 2004 contract for the ?rst time introduced payment for speci?c indicators of good clinical care in a limited range of conditions.

A telephone advice service, NHS Direct, was launched in 2000 to give an opportunity for patients to ‘consult’ a trained nurse who guides the caller on whether the symptoms indicate that self-care, a visit to a GP or a hospital Accident & Emergency department, or an ambulance callout is required. The aim of this service is to give the patient prompt advice and to reduce misuse of the skills of GPs, ambulance sta? and hospital facilities.

Training of GPs Training for NHS general practice after quali?cation and registration as a doctor requires a minimum of two years’ post-registration work in hospital jobs covering a variety of areas, including PAEDIATRICS, OBSTETRICS, care of the elderly and PSYCHIATRY. This is followed by a year or more working as a ‘registrar’ in general practice. This ?nal year exposes registrars to life as a GP, where they start to look after their own patients, while still closely supervised by a GP who has him- or herself been trained in educational techniques. Successful completion of ‘summative assessment’ – regular assessments during training – quali?es registrars to become GPs in their own right, and many newly quali?ed GPs also sit the membership exam set by the Royal College of General Practitioners (see APPENDIX 8: PROFESSIONAL ORGANISATIONS).

A growing number of GP practices o?er educational attachments to medical students. These attachments provide experience of the range of medical and social problems commonly found in the community, while also o?ering them allocated time to learn clinical skills away from the more specialist environment of the hospital.

In addition to teaching commitments, many GPs are also choosing to spend one or two sessions away from their practices each week, doing other kinds of work. Most will work in, for example, at least one of the following: a hospital specialist clinic; a hospice; occupational medicine (see under OCCUPATIONAL HEALTH, MEDICINE AND DISEASES); family-planning clinics; the police or prison services. Some also become involved in medical administration, representative medicopolitics or journalism. To help them keep up to date with advances and changes in medicine, GPs are required to produce personal-development plans that outline any educational activities they have completed or intend to pursue during the forthcoming year.

NHS GPs are allowed to see private patients, though this activity is not widespread (see PRIVATE HEALTH CARE).

Primary Care Trusts (PCTs) Groups of GPs (whether working alone, or in partnership with others) are now obliged by the NHS to link communally with a number of other GPs in the locality, to form Primary Care Trusts (PCTs). Most have a membership of about 30 GPs, working within a de?ned geographical area, in addition to the community nurses and practice counsellors working in the same area; links are also made to local council social services so that health and social needs are addressed together. Some PCTs also run ambulance services.

One of the roles of PCTs is to develop primary-care services that are appropriate to the needs of the local population, while also occupying a powerful position to in?uence the scope and quality of secondary-care services. They are also designed to ensure equity of resources between di?erent GP surgeries, so that all patients living in the locality have access to a high quality and uniform standard of service.

One way in which this is beginning to happen is through the introduction of more overt CLINICAL GOVERNANCE. PCTs devise and help their member practices to conduct CLINICAL AUDIT programmes and also encourage them to participate in prescribing incentive schemes. In return, practices receive payment for this work, and the funds are used to improve the services they o?er their patients.... general practitioner (gp)

ERGOT of rye. Secale. Claviceps purpurea, Tulasne.

Constituents: indole alkaloids, tyramine, acetylcholine.

Action: abortifacient, parturient, haemostatic, hypertensive, uterine stimulant, oxytocic. Uses. Obstetrics.

Difficult childbirth. Applied to excite uterine contractions in the third stage of labour. Preparations. Liquid Extract. BPC 1954, dose, 0.6 to 1.2ml.

Registered medical practitioner only. ... ergot

Ultrasound, or ultrasonic, waves comprise very-high-frequency sound waves above 20,000 Hz that the human ear cannot hear. Ultrasound is widely used for diagnosis and also for some treatments. In OBSTETRICS, ultrasound can assess the stage of pregnancy and detect abnormalities in the FETUS (see below). It is a valuable adjunct in the investigation of diseases in the bladder, kidneys, liver, ovaries, pancreas and brain (for more information on these organs and their diseases, see under separate entries); it also detects thromboses (clots) in blood vessels and enables their extent to be assessed. A non-invasive technique that does not need ionising radiation, ultrasound is quick, versatile and relatively inexpensive, with scans being done in any plane of the body. There is little danger to the patient or operator: unlike, for example, XRAYS, ultrasound investigations can be repeated as needed. A contrast medium is not required. Its reliability is dependent upon the skill of the operator.

Ultrasound is replacing ISOTOPE scanning in many situations, and also RADIOGRAPHY. Ultrasound of the liver can separate medical from surgical JAUNDICE in approximately 97 per cent of patients; it is very accurate in detecting and de?ning cystic lesions of the liver, but is less accurate with solid lesions – and yet will detect 85 per cent of secondary deposits (this is less than COMPUTED TOMOGRAPHY [CT] scanning). It is very accurate in detecting gall-stones (see GALL-BLADDER, DISEASES OF) and more accurate than the oral cholecystogram. It is useful as a screening test for pancreatic disease and can di?erentiate carcinoma of the pancreas from chronic pancreatitis with 85 per cent accuracy.

Ultrasound is the ?rst investigation indicated in patients presenting with renal failure, as it can quickly determine the size and shape of the kidney and whether there is any obstruction to the URETER. It is very sensitive to the presence of dilatation of the renal tract and will detect space-occupying lesions, di?erentiating cysts and tumours. It can detect also obstruction of the ureter due to renal stones by showing dilatations of the collecting system and the presence of the calculus. Adrenal (see ADRENAL GLANDS) tumours can be demonstrated by ultrasound, although it is less accurate than CT scanning.

The procedure is now the ?rst test for suspected aortic ANEURYSM and it can also show the presence of clot and delineate the true and false lumen. It is good at demonstrating subphrenic and subhepatic abscesses (see ABSCESS) and will show most intra-abdominal abscesses; CT scanning is however better for the retroperitoneal region. It has a major application in thyroid nodules as it can di?erentiate cystic from solid lesions and show the multiple lesions characteristic of the nodular GOITRE (see also THYROID GLAND, DISEASES OF). It cannot differentiate between a follicular adenoma and a carcinoma, as both these tumours are solid; nor can it demonstrate normal parathyroid glands. However, it can identify adenomas provided that they are more than 6 mm in diameter. Finally, ultrasound can di?erentiate masses in the SCROTUM into testicular and appendicular, and it can demonstrate impalpable testicular tumours. This is important as 15 per cent of testicular tumours metastasise whilst they are still impalpable.

Ultrasonic waves are one of the constituents in the shock treatment of certain types of gallstones and CALCULI in the urinary tract (see LITHOTRIPSY). They are also being used in the treatment of MENIÈRE’S DISEASE and of bruises and strains. In this ?eld of physiotherapy, ultrasonic therapy is proving of particular value in the treatment of acute injuries of soft tissue. If in such cases it is used immediately after the injury, or as soon as possible thereafter, prompt recovery is facilitated. For this reason it is being widely used in the treatment of sports injuries (see also SPORTS MEDICINE). The sound waves stimulate the healing process in damaged tissue.

Doppler ultrasound is a technique which shows the presence of vascular disease in the carotid and peripheral vessels, as it can detect the reduced blood ?ow through narrowed vessels.

Ultrasound in obstetrics Ultrasound has particular applications in obstetrics. A fetus can be seen with ultrasound from the seventh week of pregnancy, and the fetal heart can be demonstrated at this stage. Multiple pregnancy can also be diagnosed at this time by the demonstration of more than one gestation sac containing a viable fetus. A routine obstetric scan is usually performed between the 16th and 18th week of pregnancy when the fetus is easily demonstrated and most photogenic. The fetus can be measured to assess the gestational age, and the anatomy can also be checked. Intra-uterine growth retardation is much more reliably diagnosed by ultrasound than by clinical assessment. The site of the placenta can also be recorded and multiple pregnancies will be diagnosed at this stage. Fetal movements and even the heartbeat can be seen. A second scan is often done between the 32nd and 34th weeks to assess the position, size and growth rate of the baby. The resolution of equipment now available enables pre-natal diagnosis of a wide range of structural abnormalities to be diagnosed. SPINA BIFIDA, HYDROCEPHALUS and ANENCEPHALY are probably the most important, but other anomalies such as multicystic kidney, achondroplasia and certain congenital cardiac anomalies can also be identi?ed. Fetal gender can be determined from 20 weeks of gestation. Ultrasound is also useful as guidance for AMNIOCENTESIS.

In gynaecology, POLYCYSTIC OVARY SYNDROME can readily be detected as well as FIBROID and ovarian cysts. Ultrasound can monitor follicular growth when patients are being treated with infertility drugs. It is also useful in detecting ECTOPIC PREGNANCY. (See also PREGNANCY AND LABOUR.)... ultrasound

Most of the hospitals in the are part of the National Health Service.

Each district has a general hospital providing services that include medicine, surgery, gynaecology, obstetrics, and paediatrics.

Some more specialist services are concentrated in fewer centres.

Many of the ’s private hospitals are nursing homes for the elderly; others cater for nonemergency surgery, obstetric care, or inpatient care for the mentally ill.... hospitals, types of

A branch of obstetrics and paediatrics concerned with the study and care of the mother and baby during pregnancy and just after birth.... perinatology

n. (in obstetrics) see labour.... birth

n. 1. (in obstetrics) the *amnion, either as a piece of membrane that covers an infant’s head at birth or the entire unruptured sac that encloses the fetus during pregnancy. 2. (in anatomy) see omentum.... caul

System of sacred medicine originating from Ancient India, dating from 1000 to 3000BC. Most likely it goes back to Babylonian times. It is generally believed that Western medicine has grown out of Greek medicine which, in turn scholars claim to have come from India.

Ayur (“life”) and veda (“science”), the science of life, is part of the Hindu writings – the Artharva- veda. By 500BC many of these writings, including a vast collection of ‘Materia medica’ gravitated to the University of Benares, to be joined 700 years later with another huge volume of medical literature which together formed the basis of the Ayurveda system. In rural India where Western medicine is absent it is still practised by 80 per cent of the population. Like the medical culture of China, that of India is among the oldest in the world. Today, its practitioners are skilled in gynaecology, obstetrics and other specialties.

It is a branch of Holistic medicine whereby body imbalances are restored by a natural regime, baths, fasting, enemas, cleansing diets and herbs. Time is given up to meditation and prayer for which many mantras exist. Those who practise it support the role of preventive medicine, insisting it is not only a system of cure but a metaphysical way of life touching body, mind and spirit. A strict daily discipline embraces yoga and special foods to maintain a sound and wholesome life. Ayurvedic medicine regards the herb Valerian as important for epilepsy.

Important Ayurvedic medicines include Borage, Liquorice, Cinnamon, Garlic, Gotu Kola and Wild Yam, renowned for their versatility. Of special importance to this system of medicine is the hypoglycaemic plant, Gymnema sylvestre, used since the 6th century for a condition known as “honey urine”, which today grows in popularity in the West for the treatment of diabetes. ... ayurveda medicine

Pre-eclampsia. Toxaemia of last 3 months of pregnancy. Due to a number of causes, one of which is calcium deficiency. Calcium controls muscular spasms that are a feature of the condition. Eclampsia is due, in part, to a traffic jam of blood through the placenta causing a compensatory rise in blood pressure. Black women run 12 times the risk of developing pre-eclampsia during their first pregnancy as non-black women. (American researchers)

Women who use barrier contraceptives are more than twice as likely to develop pre-eclampsia in pregnancy than those using non-barrier methods. (North Carolina Memorial Hospital)

Symptoms. Headache, dizziness, nausea, upper abdominal pain, twitching of face and limbs, albumin in the urine. Extreme cases: high blood pressure, rigidity, congestive heart failure.

Treatment. Hospitalisation. To be treated by qualified obstetrician.

Formula. Cramp bark 2; Motherwort 1; Black Cohosh 1. Dose: Powders: 750mg (three 00 capsules or half a teaspoon). Liquid extracts: one to two 5ml teaspoons. Tinctures: 1-3 teaspoons. Hourly, or more frequently as tolerated; in water or honey. Magnesium sulphate for fits.

Suppression of urine. Dilation of kidney arterioles to increase flow of blood and to re-start kidney function.

Bearberry (Uva Ursi) tea. 1-2 teaspoon to each cup boiling water; infuse 15 minutes; 1 cup freely. Bearberry Liquid extract. 2-4ml hourly, or as tolerated, in water or honey.

White Willow. Conventional treatment places high-risk women on low-dose aspirin therapy. As White Willow is a source of natural aspirin, it would appear to offer some benefit. White Willow reduces platelet aggregation, and encourages placental blood flow. Aspirin of pharmacy cuts the risk of pregnancy-induced high blood pressure by two-thirds.

Diet. Pre-eclampsia: oily fish or fish oil supplements. (Journal of Obstetrics and Gynaecology 1990, 97 (12) 1077-79)

Supplements. Calcium. Magnesium.

Note: A serious condition which can be fatal but which can be prevented by regular antenatal examinations by a qualified obstetrician. ... eclampsia

n. (in obstetrics) the stage of pregnancy that occurs when the presenting part of the fetus has descended into the mother’s pelvis. Engagement of the fetal head occurs when the widest part has passed through the pelvic inlet.... engagement

a classification drawn up by the International Federation of Gynaecology and Obstetrics to define the extent of the spread of gynaecological cancers.... figo staging

n. 1. (in obstetrics) the starting of labour by artificial means. It is carried out using such drugs as *prostaglandins to prime the cervix and/or *amniotomy prior to synthetic *oxytocin (Syntocinon), which stimulate uterine contractions. Induction of labour is carried out if the wellbeing or life of mother or child is threatened by continuance of the pregnancy. 2. (in anaesthesia) initiation of *anaesthesia. General anaesthesia is usually induced by the intravenous injection of short-acting *anaesthetics, e.g. thiopental.... induction

n. 1. the softening of a solid by leaving it immersed in a liquid. 2. (in obstetrics) the natural breakdown of a dead fetus within the uterus.... maceration

n. (in obstetrics) an abnormal position of the fetal head when this is the presenting part in labour (see presentation). The head is in such a position that the diameter of the skull in relation to the pelvic opening is greater than normal (e.g. occipital transverse, occipital posterior: see occiput). This is likely to result in a prolonged and complicated labour.... malposition

inhalation of regurgitated stomach contents by an anaesthetized patient, which may result in death from anoxia or cause extensive lung damage or pulmonary *oedema with severe *bronchospasm. It is a well-recognized hazard of general anaesthesia in obstetrics and may be prevented by giving gastric-acid inhibitors (e.g. *cimetidine or *ranitidine) or sodium citrate before inducing anaesthesia. [C. L. Mendelson (1913–2002), US obstetrician]... mendelson’s syndrome

n. the profession of providing assistance and medical care to women undergoing labour and childbirth during the antenatal, perinatal, and postnatal periods. See also community midwife; obstetrics. —midwife n.... midwifery

n. the back of the head. In obstetrics, the occiput is used as a *denominator when a fetus presents by the vertex (see presentation). The most favourable position for delivery is occipitoanterior (or occipital anterior), with the occiput of the fetus presenting towards the anterior aspect of the maternal pelvis as it enters the pelvic inlet. In the occipitotransverse (or occipital transverse) and occipitoposterior (or occipital posterior) positions, the occiput presents towards the lateral and posterior aspects, respectively, of the maternal pelvis; these are *malpositions. —occipital adj.... occiput

n. the general medicine of childhood. Handling the sick child requires a special approach at every age from birth (or preterm birth) to adolescence and also a proper understanding of parents. It also requires detailed knowledge of genetics, obstetrics, psychological development, management of disabilities at home and in school, and effects of social conditions on child health. The preventive measures associated with all these aspects of paediatrics are the concern of *public health consultants and *community paediatricians. See also child health clinic. —paediatrician n.... paediatrics

vb. 1. (of a patient) to come forward for examination and treatment because of experiencing specific symptoms (presenting symptoms). 2. (in obstetrics) see presentation.... present

n. 1. (in obstetrics) the state of uterine muscle fibres remaining shortened after contracting during labour. This results in a gradual progression of the fetus downwards through the pelvis. The basal portion of the uterus becomes thicker and pulls up the dilating cervix over the presenting part. 2. (in dentistry) the drawing back of one or more teeth into a better position by an *orthodontic appliance. 3. (in dentistry) the stretching of facial tissues to expose only the teeth during dental photography.... retraction

n. (in obstetrics) any one of the three successive three-month periods (the first, second, and third trimesters) into which a pregnancy may be divided.... trimester

(sonography) n. the use of *ultrasound to produce images of structures in the human body. The ultrasound probe sends out a short pulse of high-frequency sound and detects the reflected waves (echoes) occurring at interfaces within the organs. The direction of the pulse can then be moved across the area of interest with each pulse to build up a complete image. Scans may produce a single stationary image similar to a photograph (static) or multiple sequential images similar to a video (*real-time imaging). The ultrasound waves are transmitted from – and echoes detected by – piezoelectric crystals contained within the scanning probe (see transducer). As far as is known, there are no significant adverse effects from the use of ultrasound at diagnostic energies. Ultrasound waves are blocked by gas, as in the lungs and bowel, which can obscure underlying structures. The detail seen increases with the frequency of the ultrasound but the depth of penetration decreases. Ultrasonography is extensively used in obstetrics, including the diagnosis of pregnancy, assessment of gestational age, diagnosis of *malpresentations, ectopic pregnancies, and *hydatidiform moles, and detection of structural fetal abnormalities (see also transvaginal ultrasonography). It is also used to examine the abdominal organs, urinary tract, blood vessels, muscles, and tendons. More specialized techniques include *echocardiography, *transrectal ultrasonography (TRUS), intraoperative ultrasound (IOUS), and endoscopic ultrasound examinations. See also Doppler ultrasound.... ultrasonography