2: OBSTETRICS

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CHAPTER 2 OBSTETRICS

PRECONCEPTUAL COUNSELLING

Preconceptual counselling ensures that the woman is fully informed about measures which may be taken to protect herself and the developing foetus during any future pregnancy.

Management

Advice

Smoking and alcohol.

Women should be advised to stop smoking and to reduce their alcohol intake to a minimum.

Diet and nutrition

• Advise a well-balanced diet.

• Advise a diet rich in folic acid (green vegetables, bread, potatoes, fruit and fortified cereals). Advise all women to take supplements of folic acid, 400 mg per day, from before conception to 12 weeks of gestation. This may reduce the risk of neural tube defects. (Folic acid can be prescribed on FP10 or bought OTC.)

• To minimise the risk of listeriosis, avoid unpasteurised soft cheeses, cooked chilled foods, prepacked salads and pâtés.

• To minimise the risk of toxoplasmosis, avoid undercooked meat, wash all vegetables and fruit prior to consumption, and avoid handling soil or cat faeces.

• Avoid high vitamin A intake.

• Avoid peanuts.

• Advise a high-calcium diet or calcium supplements for women who may require it, e.g. grand multiparous women or those who are socially deprived.

Contraception.

If oral contraception or an IUCD is being used, one natural period without contraception should ideally be allowed before conception.

Referral

Obstetric problems

• Previous miscarriages: if the woman has had three or more miscarriages, refer for assessment of, e.g. cervical incompetence (which tends to cause mid-trimester miscarriages) or chromosomal abnormalities.

• Previous still births, foetal abnormalities or a family history of foetal abnormalities: refer for genetic counselling where this is likely to be beneficial. Advise, where appropriate, on antenatal screening and diagnosis. If the patient has a previous history or family history of a neural tube defect, advise her to take folic acid 5 mg daily from 1 month prior to stopping contraception to 12 weeks of gestation.

Medical problems

• Hypertension: refer for assessment. Methyldopa and some beta blockers, e.g. propranolol, are known to be safe and effective in pregnancy.

• Diabetes: refer for assessment. Perinatal mortality is around 10%, even with excellent control of blood sugar, which is crucial. The incidence of congenital abnormalities can be significantly reduced by good blood sugar control both before and during pregnancy. HbA_1c levels should be checked before stopping contraception.

• Epilepsy: refer for assessment. Congenital abnormalities are more than twice as common as usual. All anticonvulsants increase the incidence of foetal abnormalities to varying degrees, and this has to be assessed against the risk of untreated epilepsy and convulsions during pregnancy.

BOOKING VISIT

The booking visit is ideally between 8 and 14 weeks, and usually requires a 20–30 minute appointment.

Diagnosis

Pregnancy can be confirmed by home or laboratory testing of an early morning urine specimen taken after a missed period, measuring urinary HCG.

A diagnosis of pregnancy can usually be made on the history alone.

History.

• LMP (and degree of certainty of that date), and calculate EDD

• age, occupation, race of both patient and partner (if appropriate), medical and obstetric problems (see p. 23), socioeconomic background, family history, alcohol, smoking and dental hygiene.

Examination

• legs (for varicose veins)

Vaginal examination is unnecessary.

Management

After assessing risk factors, discuss the most appropriate form of antenatal and intrapartum care. The usual options are ‘shared care’ (the patient’s care is shared between hospital doctors and GPs/midwives, and the mother is delivered by the hospital team) and community care (involving the GP and the community midwives with delivery in hospital, community units or at home). Arrangements and criteria for low-risk community units will vary according to the locality. Refer as appropriate.

Advice

• Discuss diet (see p. 22).

• Discuss prenatal screening and diagnosis (see p. 25), as appropriate.

• Discuss the woman’s concerns and expectations with regard to the pregnancy and delivery.

Administration

• Complete form FW8. This authorises free prescriptions and dental care throughout the pregnancy and for 12 months after delivery.

• Complete the relevant maternity hospital registration form.

PRENATAL SCREENING AND DIAGNOSIS

SCREENING TESTS

All women may be offered ultrasound, serum AFP and the triple test or integrated test as part of routine screening. Discussion of the pros and cons of these tests must take account of the patient’s feelings regarding termination of pregnancy. False-positive results can cause considerable unnecessary anxiety. Diagnostic tests are necessary to confirm a positive screening test.

Serum AFP.

This is performed from 15 weeks. A high level indicates a higher risk of neural tube defect, or twins. A low level indicates a higher risk of Down’s syndrome.

Triple test.

This is a blood test, performed between 15 and 21 weeks and in some areas only available privately; it estimates the risk of Down’s syndrome and neural tube defects. The estimated risk of Down’s syndrome is based on serum AFP, HCG and unconjugated oestriol, as well as maternal age. The risk of a neural tube defect is based on AFP alone. It is particularly helpful for older mothers. (The risk of Down’s at age 35 years is 1:400, while at age 40 it is 1:100.)

Integrated test.

This is the best available screening test. It involves:

• a 10–13 week nuchal scan

• a 10 week assay of serum pregnancy associated protein A

• a 14 week quadruple test (serum AFP, B-HCG, unconjugated oestriol and inhibin-A).

The measurements are integrated into a single screening result, taking account of maternal age. The test detects 92% of Down’s syndrome babies, with a false-positive rate of only 0.9%. Other tests involving a nuchal scan and blood tests are also available. In most areas they are only available privately.

DIAGNOSTIC TESTS

Chorionic villus biopsy.

This is performed at 8–12 weeks, allowing termination in the first trimester if an abnormality is confirmed. It enables early detection of chromosomal abnormalities and other rare genetic diseases. There is a 1–2% miscarriage rate. Limb deformities are a rare risk of this biopsy.

Amniocentesis.

This is performed at 15–16 weeks, allowing termination before 20 weeks if an abnormality is confirmed. The miscarriage rate is 0.5–1%. It detects Down’s syndrome, X-linked disorders (e.g. haemophilia and Duchenne muscular dystrophy) and some inborn errors of metabolism (e.g. Tay–Sachs disease). Results of fluid analysis for AFP usually take 1 week, while cell culture for karyotype or biochemistry takes 3 weeks. Anti-D is given if the woman is rhesus negative.

BLEEDING IN EARLY PREGNANCY (<14 WEEKS)

Management

For vaginal spotting without pain:

• Telephone advice is usually adequate.

• Advise to rest at home.

For vaginal bleeding with pain:

• Mild discomfort and light bleeding can usually be managed at home.

• Worsening pain usually suggests the need for admission, especially if it is associated with the passing of clots.

• An open cervix confirms the need for admission. If the bleeding is heavy, remove any products of conception, with a gloved hand, and give syntometrine im, 1 ml.

Vaginal bleeding at >12 weeks in a rhesus-negative woman requires an injection of anti-D 500 IU im within 72 hours of the start of bleeding. At <12 weeks, anti-D only needs to be given if the bleeding is heavy, e.g. ERPC is required.

If the miscarriage is complete (i.e. products have been passed and the pain and bleeding have settled):

• Advise rest at home and arrange early review.

• Tell the patient to contact the doctor if bleeding recurs.

• Give an explanation, as appropriate:

– the likely cause is foetal abnormality or implantation failure

– investigation is not useful in first-trimester miscarriages unless there have been three or more.

• Bereavement counselling is often important.

If the pregnancy continues and the symptoms settle:

• Review. If not already performed, arrange an ultrasound scan to exclude a missed abortion.

• Explain that bleeding in pregnancy does not increase the risk of foetal abnormalities.

BLEEDING IN LATER PREGNANCY

After 14 weeks, admission should be arranged when bleeding occurs, with or without pain. Bleeding with severe pain is likely to be due to placental abruption. If the woman’s blood group is rhesus negative, she requires an injection of anti-D 500 IU im within 72 hours of the start of bleeding.

Do not perform a vaginal examination after 14 weeks in case of placenta praevia.

NAUSEA AND VOMITING

Vomiting in pregnancy can be extremely debilitating and the patient often requires considerable support and reassurance.

Management

• Explain that the symptoms are likely to resolve by 14–16 weeks.

• Encourage fluids (carbonated drinks can be helpful) and frequent, small, plain meals.

• Consider drug treatment if the symptoms are severe, e.g. promethazine 25 mg mane, 50 mg nocte.

• Consider admission if vomiting is prolonged or dehydration is a concern.

HEARTBURN

Heartburn usually worsens as pregnancy progresses. It can be exacerbated by oral iron.

Management

• Recommend frequent small meals.

• Prescribe an antacid with a low sodium content, e.g. Maalox 10 ml after meals or prn.

SWOLLEN ANKLES

Swollen ankles are common in pregnancy.

Management

• Exclude pre-eclampsia. (Check for more generalised oedema, hypertension and/or proteinuria.)

• Advise the patient to avoid long periods of standing. If oedema becomes uncomfortable, advise her to sit with the ankles above the level of the hips when resting, and to wear support stockings or tights (see below).

VARICOSE VEINS

Varicose veins tend to worsen with each pregnancy.

Management

• Avoid long periods of standing.

• Advise the patient to sit with the ankles above the level of the hips when resting, and to wear support stockings or tights. Support stockings are obtainable on FP10 in three grades. Support tights are usually more comfortable, but are only available OTC. Support hosiery should ideally be put on before getting out of bed in the morning.

• Surgery should be avoided until the woman has completed her family.

PROTEINURIA

A trace of protein in the urine can be ignored.

Management

• Check the blood pressure to exclude pre-eclampsia.

• Arrange an MSU to exclude a UTI.

• If the MSU is negative, exclude any underlying renal disease by checking serum creatinine and 24-hour urinary protein. (Proteinuria in pregnancy is defined as >300 mg/l.)

• Refer as appropriate.

ANAEMIA

The importance of severe anaemia during pregnancy is that perinatal mortality is increased and postpartum haemorrhage may become life-threatening.

Haemoglobin is measured routinely at booking, and at 28 and 34 weeks. The Hb concentration falls during pregnancy due to haemodilution. A low to normal Hb (10–11 g/dl) with a normal MCV and MCH suggests simple haemodilution. A pregnant woman is anaemic if the Hb is <10.

Management

Mild anaemia can initially be assumed to be secondary to iron deficiency and treated with, e.g., Pregaday, one tablet daily (100 mg elemental iron as ferrous fumarate and 350 mg of folate). Check the Hb 2 weeks later. It should rise at the rate of 0.5 g/dl per week. If the response is poor, or if the anaemia is more severe, double the dose of Pregaday. Check 2 weeks later, and refer if the haemoglobin is <9.

Iron prophylaxis

This should be given to those at high risk of deficiency, e.g. those with:

• a poor diet

• closely spaced pregnancies

• a past history of iron deficiency anaemia.

Folate prophylaxis

This should be given to all mothers at a dose of 400 mg per day up to 12 weeks of pregnancy. A higher dose of 5 mg per day should be given to mothers with a previous spina bifida child or a family history of spina bifida, as well as to mothers with:

• a past history of folate deficiency

• malabsorption

• haemoglobinopathies

• anticonvulsant therapy, e.g. phenytoin

• multiple pregnancies

• grand multiparity.

ABNORMAL LIE

An oblique or transverse lie or breech presentation should be referred for hospital assessment from 34 weeks for discussion of possible trial of external cephalic version and/or mode of delivery.

HIGH HEAD

A ‘high head’ (i.e. one that lies totally outside the pelvis) is of less significance in a multiparous woman who has already experienced a vaginal delivery than in a primiparous woman. Before making this diagnosis, ensure that the bladder is empty. It is useful to ask the patient to lift her upper body onto her elbows. This may cause the head to descend. Refer primiparous women at 34 weeks for consultant assessment, and arrange an ultrasound to assess placental position. Multiparous women should be referred at 38 weeks for assessment of placental position, if not already known.

BACK PAIN

Back pain in pregnancy is usually lumbar, secondary to ligament laxity.

Management

• Advise on posture: try to eliminate, as far as possible, the lumbar lordosis when standing and sitting.

• Avoid heavy lifting.

• An elastic back support may be helpful (obtainable OTC or from the maternity physiotherapy department).

• Consider referral to maternity physiotherapy.

POSTPARTUM BLEEDING

The lochia usually disappear by 6 weeks. However, they may persist for some further weeks, and as long as they are decreasing and fading to pink or brown the patient can be reassured.

If the lochia remain red but bleeding is mild, consider using oral ergometrine 500 μg tds for 3 days. Co-amoxiclav 1 tds for 7 days may be useful in suspected endometritis (see below).

If bleeding is excessive (especially if there are clots present) or if the patient is pyrexial, admit with a view to ultrasound and/or ERPC.

POSTPARTUM PYREXIA

UTIs, DVTs and breast infections may present with pyrexia. Patients with endometritis (fever, foul discharge and low abdominal pain) should be admitted with a view to ERPC and/or intravenous antibiotics. (Foul lochia without fever can be treated at home with amoxicillin and metronidazole, or co-amoxiclav.)

POSTNATAL DEPRESSION

The maternity blues are considered to be normal. They are experienced by one-half to two-thirds of mothers, and usually occur in the first week. Postnatal depression, however, affects 10–15% of mothers, usually within the first 3 postnatal months.

Management

• The health visitor can play an important role in non-directive counselling. Encourage women to discuss their own needs separately from those of the baby.

• Antidepressants play an important role. Most are secreted in breast milk. Lofepramine 140–210 mg daily in divided doses is safe for breast-feeding mothers. The higher dose is often necessary.

• Consider involving other social support agencies, e.g. a social worker.

• Refer for counselling or to a psychiatrist, as appropriate.

• See depression (p. 292).

POSTNATAL CHECK

This takes place at 6 weeks. It is often the first time that the GP and the mother meet after the immediate postnatal period. It is a particularly important time to assess maternal mood.

Assessment

History.

• any continuing vaginal bleeding (persisting brown lochia is neither uncommon nor abnormal; see also p. 32)

• feelings about the birth and postnatal period

• sleep, mood, perineal discomfort, incontinence and breast- or bottlefeeding

• contraception

• rubella status.

Examination

• BP (especially if raised in pregnancy).

• Weight (if appropriate).

• Abdomen for muscle laxity. When divarication of the recti muscles is significant (i.e. three or more fingers’ breadths can be inserted between them), consider referral to a maternity physiotherapist.

• Breasts, especially if there are specific problems, e.g. sore nipples.

• Perineal wounds. Intercourse may already be pain-free, but there is often residual perineal soreness and tenderness.

• If a cervical smear is due, it is ideally delayed until about 3 months postpartum.

Management

• See sections on breast-feeding (p. 35) and postnatal depression (p. 33), if appropriate.

• Discuss the importance of long-term abdominal and pelvic-floor exercises. Consider referral to a maternity physiotherapist if pelvic-floor weakness is significant.

BREAST-FEEDING

Many early breast-feeding problems, e.g. mastitis, sore nipples and infant colic, are likely to be due to a failure to position the baby correctly on the breast. Therefore, always ensure a good feeding position. The midwife and health visitor are best placed to advise. Encourage unrestricted, demand feeding in order to stimulate lactation, and advise the mother to avoid giving the baby additional water or supplementary feeds, if possible.

SORE OR CRACKED NIPPLES

• Check positioning: the nipple should be in the roof of the baby’s mouth, thus avoiding friction from the tongue.

• Encourage continued suckling as far as possible.

• Creams, ointments and local treatments are probably not effective.

• Apply breast milk to sore nipples and allow them to dry.

ENGORGEMENT

• Check positioning.

• Encourage continued suckling.

• A good supportive bra is helpful.

• It is often helpful to express engorged breasts gently before feeds. This may be more comfortable in a warm bath.

• Cold compresses between feeds may be soothing.

BLOCKED DUCTS (CAUSING TENDER LUMPS)

• Check positioning.

• Feed on the tender breast first.

• Gentle massage of a hard lump while feeding may be helpful. The milk should be smoothed towards the nipple.

MASTITIS

• A segment of the breast is usually red and tender and the patient is often pyrexial.

• 50% of cases may be non-infective, i.e. related to poor positioning, engorgement or localised obstructions (see above).

• If appropriate, treat with flucloxacillin 500 mg qds for 5 days (or erythromycin if the patient is allergic to penicillin). Antibiotic treatment will alter the taste of the milk and may cause the baby to develop mild diarrhoea.

SUPPRESSION OF LACTATION

• Lactation is naturally suppressed within 5 days of the cessation of breast-feeding.

• Advise simple analgesia and good breast support only.

• If lactation needs to be stopped more quickly, e.g. after stillbirth, prescribe bromocriptine 2.5 mg daily for 3 days and then increase to 2.5 mg bd for 2 weeks.

Related

Churchills Pocketbook of General Practice