The incidence of pulmonary tuberculosis remains high in many developing countries and it is therefore commonly associated with pregnancy. It is important that the attendant should be aware of this, and should look for a history suggestive of tuberculosis whenever the pregnant patient presents. Clinical examination of the chest should always be performed. Where there is a high incidence of tuberculosis, and chest radiography is easily available, routine screening is indicated.
If the disease is diagnosed in pregnancy the ideal management would be in-patient treatment until the disease is controlled, followed by out-patient therapy.
This would be an opportunity also for rest and advice on diet. Where this is not possible, out-patient treatment has to suffice with efficient follow-up of defaulters. Drug regimens vary with local programmes, and with cost and availability of drugs. An example would be isoniazid (300 mg) and ethambutol (15 mg/kg daily) for one year. These women are often anaemic as well and prophylactic haematinics should be prescribed.
In labour, care should be taken to maintain adequate hydration and to prevent respiratory embarrassment, and the second stage should be shortened by timely prophylactic forceps delivery or vacuum extraction which can be performed in the health centre.
Management of the neonate
In the tropics the decision as to whether to allow the infant to breast-feed has to be based on the relative dangers of tuberculous infection from the mother, and disease and death from unhygienic bottle-feeding.
If the mother has been effectively treated the child should breast-feed but should also receive BCG vaccination in the neonatal period. This should be repeated at about six weeks if tuberculin testing is negative. Should the mother still be infectious at the time of delivery she must be given antituberculous therapy immediately. If INAH-resistant BCG is avail-able it should be given to the infant at birth; the infant breast-fed and protected from tuberculosis by prophy-lactic INAH. This should be continued until Mantoux conversion occurs. Should INAH-resistant BCG not be available, the child can be given ordinary BCG at birth, followed by temporary segregation from the mother (while the breasts are manually expressed) and the commencement of INAH prophylaxis and breast-feeding. This should be continued until the mother is non-infectious, or the child has achieved Mantoux converSIOn.
Heart disease
Physiological changes in pregnancy and labour Pregnancy is a time of added strain to the cardio-vascular system. Cardiac output rises in the first trimester, continues to rise until about 32 weeks, and remains at this high level until term. Heart rate increases 10 to 15 beats per minute, reaching its peak near term, while stroke volume is highest in early to mid pregnancy. Blood volume increases variably in different women most rapidly during the first 20-30 weeks of gestation, and continuing gradually to term.
Common medical diseases 141 Plasma volume often increases more than red cells, causing a lowering of haemoglobin values if iron supplies are insufficient. Labour and delivery impose a further burden on the heart, and this is compounded by pain and anxiety.
The problem of heart disease in pregnancy
In developed parts of the world, the incidence of heart disease in pregnancy has lessened and changed in pattern; less rheumatic heart disease is seen, and more congenital heart disease, often post-surgery. However, in poorer countries, rheumatic heart disease is still common, and pregnant patients with heart disease are a significant risk group. Pregnancy may be the first opportunity for diagnosis, and antenatal clinic staff should be alert to this.
Clinical classification of physical disability in the non-pregnant state, and the nature of the lesion are the best guide to prognosis when sophisticated investi-gation is not available.
The aim of medical care throughout pregnancy and delivery is the prevention of cardiac failure and the other complications of heart disease. The patient must therefore be seen more often and by the most experienced personnel available. She must rest more than her healthy sister, and may need to be admitted to hospital for prolonged periods. Anaemia should be prevented, or energetically treated when diagnosed.
Dental extractions should be covered with antibiotics and infections, e.g. in the chest, regarded as potentially dangerous. Antibiotics should be given in labour also.
Tachycardia, cardia arrhythmias, pulmonary oedema and cardiac failure should be looked for, diagnosed early and treated. If anticoagulants are needed heparin is safe in pregnancy.
Ideally the patient should be resting in hospital when she goes into labour (digoxin causes earlier and shorter labour) and this should be as pain- and anxiety-free as possible. Conduction anaesthesia is ideal if available, and if Caesarean section is necessary for obstetric reasons, it can be done under epidural anaesthesia. The condition of the mother should be very closely moni-tored, and the second stage shortened by forceps delivery. Intravenous oxytocics should usually be avoided, and particular vigilance taken during the hours following delivery, as complications are more likely at this time. Return to normal activity should be gradual and contraceptive advice should be given in the hope that birth intervals will be prolonged and family size limited. Sterilization may be indicated in some cases.
142 Maternal health
Diabetes
Diabetes and pregnancy are an unhappy partnership.
Pregnancy is a diabetogenic state and therefore makes diabetes worse, and diabetes is associated with many complications in pregnancy, from preconception to puerperium. Diabetic pregnancy outcome will only be suecessful when the diabetes is controlled meticulously from preconception through delivery, and this requires, if possible, the supervision of an experienced physician and obstetrician, the availability of drugs and equip-ment for monitoring and a motivated, cooperative patient. All this emphasizes the difficulty of achieving good results in diabetic pregnancy in much of the developing world.
Principles, however, remain. If a woman is known to be a diabetic, she should be counselled about the importance of preconception diabetic control and advised about antenatal and delivery care. An estima-tion of glycosylated HbA if available, reflects the degree of metabolic control in a patient over the previous months. During pregnancy, the ideal management is to maintain a blood glucose below 120 mg/lOO ml (approx. 7 mmolll), and this often needs a controlled diet and changing combinations of soluble and isophane insulin, which in turn requires an efficient monitoring system. This is often very difficult to achieve in the Third World, but every effort should be made to see the pregnant diabetic regularly and adjust treatment according to blood glucose levels. Pro-longed hospitalization may be the only way to achieve this, and patients and their families need to be con-vinced that one or two well-supervised pregnancies with successful outcome are far better than several resulting in perinatal death. The severity of the dia-betes is a guide to the outcome of pregnancy, but all need close surveillance.
Diabetes may be diagnosed for the first time in pregnancy. The attendant should look for factors such as unexplained stillbirth or neonatal death, or a history of a baby weighing more than 4000 g in a previous pregnancy, and investigate these patients as early as possible.
Routine screening by urine examination for glucose and further investigation of those with glycosuria, remains sound practice. However, the availability of resources and the prevalence of diabetes in the population, will determine the extent of screening. It is far better to screen potential diabetics routinely than to screen all patients while reagents last and then screen nobody.
The obstetric management should look for compli-cations in the fetus caused by the diabetes, monitor
growth and well-being of the fetus by whatever methods are available and decide on the optimum time and method of delivery. In early pregnancy it is important to assess the gestation as accurately as possible from menstrual history, uterine size and ultrasound examination if available. Ultrasound examination will also assist in the diagnosis of fetal abnormalities. This early contact with the mother is an opportunity for convincing her of the importance of good diabetic control and for teaching her any home monitoring methods that are available. As the pregnancy progresses, the obstetrician should look for signs of hydramnios and excessive fetal growth, which are evidence of poor control and fetal compromise, as well as for pregnancy complications such as hypertension and pyelonephritis, which may have more sinister effects in the diabetic than the normal pregnancy.
Preterm labour, intrauterine deaths and neonatal morbidity are also more common III diabetic pregnancy.
Fetal well-being has to be assessed by whatever methods are possible. Clinical assessment of fetal size and the presence of hydramnios remain important, even if regular antenatal fetal heart monitoring and ultrasound examinations are available.
If insulin-treated diabetic control is satisfactory and there is no evidence of fetal compromise, macrosomia, hydramnios or pre-eclampsia, then labour can be induced at 37 to 38 weeks. If diet alone has achieved good control, and providing there is no evidence of placental insufficiency, induction can be left to 39 to 40 weeks, allowing more possibility of spontaneous labour.
Intravenous infusion of 5 per cent glucose is commenced one hour before and continued at 80 ml per hour. A simple regimen would be to give 14 units isophane insulin subcutaneously; others prefer to give half the normal morning dose of soluble insulin.
Rupture of the forewaters is performed and intravenous syntocinon infusion in normal saline commenced.
Progress should be good and the labour complete within 12 hours. Close monitoring of the fetal heart is essential, with maternal blood sugar estimation done every two hours and the infusion adjusted to keep this between 4 and 8 mmol/l. Failure to progress will justify intervention and delivery by Caesarean section.
Mothers with a previous bad obstetric history will need delivery by elective Caesarean section at 37 weeks.
Care should be taken in the 24 hours after delivery, as hypoglycaemia may result from postpartum increased sensitivity to insulin. The mother's insulin require-ments will then usually return to prepregnancy levels.
Following delivery, contraceptive advice should be
given and the parents reminded again of the advis-ability of limiting family size.
Hypertension
The older the childbearing population, the more common is hypertension and its complications. This will usually be due to essential hypertension, but may also be due to renal disease and to rare causes like phaeochromocytoma, coarctation of the aorta and Cushing's syndrome. The importance of chronic hypertension in pregnancy is that it is one of the major predisposing factors of pre-eclampsia and also intra-uterine growth retardation.
Chronic hypertension can only be diagnosed with confidence in pregnancy if it is known to be present outside pregnancy, or if a blood pressure of 140190 or over is found on two occasions before 20 weeks. If a pregnant patient is first seen in the middle trimester, the usual physiological decrease in blood pressure may mask such hypertension, and if she is seen later in pregnancy it is difficult to distinguish between this and pre-eclampsia. Treatment is only necessary in pregnancy for maternal reasons, and a maximum blood pressure of 160/100 would be an acceptable level of control. The drug methyldopa (dosage 250-500 mg three times a day) is preferred, as it has proved not to have teratogenic or other adverse effects on the fetus.
However, more recently labetalol, a combined ex - and
13 -
adrenoceptor blocking drug (dosage 100-200 mg three times a day) is becoming more widely used.Diuretics would only rarely be needed for control of hypertension; it should be noted that they have dis-advantages in superimposed pre-eclampsia. It is important to remember that a raised blood pressure, whenever it is found, implies a significant risk and the patient must be seen more often and referred to hospital if necessary. These patients will often need varying periods of hospitalization.
Renal disease
The most common renal complication of pregnancy is acute pyelonephritis which presents with pyrexia, pain, frequency, and vomiting. It may cause abortion, pre-term labour and intrauterine death. Antibiotic therapy should be aggressive (commenced while waiting for bacterial culture sensitivities) and continued for about three weeks. After cessation of treatment, regular urine cultures should be taken. Seventy per cent of these patients will have had asymptomatic bacteriuria, and if tests are available it is worth screening for bacteriuria early in pregnancy. The 2 to 5 per cent of patients who