Chapter 9. The medicine of pregnancy

Table of Contents
Anaemia in pregnancy
Diabetes in pregnancy
Hypertension in pregnancy
Heart failure in pregnancy
Urinary infection and chronic renal disease in pregnancy

Anaemia in pregnancy

Severe anaemia in pregnancy makes a mother sick, and in some parts of the world it commonly kills her as the result of congestive heart failure, before, during, and after labour. Anaemia impairs her resistance to genital and respiratory infection, and the cerebral anoxia it causes can lead to mental confusion and coma. How ill she is depends on how rapidly her anaemia developed. If it developed slowly, she may have suprisingly few symptoms. Even so, a traumatic delivery or a small blood-loss can kill her. Severe anaemia can also harm her baby by causing ]]late abortion, prematurity, low birthweight (IUGR, 19.13), and perinatal deaths. Even moderate anaemia harms him, and severe anaemia can cause a perinatal mortality of thirty per cent.

Mild anaemia (down to 100 g/l) is physiological and is the result of the plasma volume expanding during pregnancy. More severe anaemia is caused by: (1) P. falciparum malaria, especially in primips. (2) Iron deficiency, especially in grand multips, and in patients with hookworms. (4) Folate deficiency, especially if they also have malaria, malnutrition, or twins. (3) Sickle-cell disease and other haemoglobinopathies. (4) AIDS. Fortunately, anaemia is also cheaply preventable, and fairly easily treated; if this is done promptly, it will remove most of its risks to her and her baby. So find out what the causes are in your area and adapt the regime below to them. You will need to measure her haemoglobin. The most practical instruments for doing this at the present time are the Spencer haemoglobinometer (AOC) and the microhaematocrit centrifuge.

Unfortunately, you may see her for the first time late in pregnancy, when she may need blood. The risk of transfusion is that it will increase her blood volume, and may precipitate cardiac failure. You can minimize this risk by giving her packed cells only, by transfusing her slowly, and by giving her a rapidly acting diuretic.

The prevention of anaemia in pregnancy is a community problem. Births must be spaced, parasites controlled, nutrition improved, and prophylactic treatment given to all mothers from the beginning of pregnancy.

Malaria especially falciparum malaria: (1) Destroys red cells and so causes anaemia, which may be megaloblastic if she also has a secondary folate deficiency. (2) Causes abortions, perinatal deaths, premature labour, and low birthweight (IUGR, 19.13). If she is non-immune, her placenta may be so heavily parasitized that it is black with malarial pigment. Malaria may be more serious in areas where it is unstable, than in those in which it is stable. In an area of stable malaria, she may only get attacks when she is pregnant, especially during the second trimester, and while she is a primip.

Antimalarials have their risks. In a village mother in an endemic area the risks lie strongly with the parasite[md]she needs prophylaxis, either from the antenatal clinic, or through PHC workers[md]if you can get them the drugs. For a minimally exposed visitor to an endemic area, you will have to balance the risk of malaria against those of the drugs to prevent it.

Chloroquine gives the best and safest protection against sensitive strains of P. falciparum, and all the other malaria parasites. Proguanil is safe in pregnancy. Although the antifolate pyrimethamine is theoretically embryopathic, it seems to be safe in practice. One contributor considers it should be supplemented with folic acid, especially during the first trimester. Avoid ''Fansidar' (pyrimethamine/sulphadoxine) except for the treatment of chloroquine-resistant strains (see below). ''Maloprim' (dapsone/pyrimethamine) is controversial; one tablet a week gives fairly good protection if there is little resistance locally to pyrimethamine, and is said not to be embryopathic. One contributor considers it should be supplemented with with folic acid.

Fig. 17-1 THE PATHOPHYSIOLOGY OF ANAEMIA, malaria, iron-and- folate deficiency in pregnancy. Kindly contributed by Alan Fleming, from a Distance Learning Module prepared by the Wellcome Tropical Institute.

SEVERE ANAEMIA PREVENTION DEFICIENCY ANAEMIA. If anaemia is common, give all mothers ferrous sulphate 200 mg with folate 50 [gm]g once daily throughout pregnancy. This is the standard UNICEF tablet. There is no need for other more expensive preparations. If anaemia is not common, treat only those with anaemia. Healthy well nourished non-anaemic mothers do not need extra iron in pregnancy.

MALARIA. In highly malarious areas give all mothers, especially all primips, a curative dose of the appropriate antimalarial (usually chloroquine 600 mg base once and 300 mg twice a day for two days), on first coming to the antenatal clinic, and then give them weekly prophylaxis until 4 weeks after delivery.

If the local strains are completely or partly chloroquine-sensitive, give her 5 mg/kg chloroquine base once a week. In some areas a higher dose may be necessary.

If there is chloroquine resistance locally, the choice of drugs is difficult. Proguanil (''Paludrine') 100 mg daily may be suitable. One contributor advises proguanil in all circumstances and never gives chloroquine prophylactically, on the grounds that its routine use for prophylaxis in the community promotes chloroquine resistance.

If she is normally immune, and gets a clinical attack during pregnancy, give her a full curative dose of chloroquine as above. If she is not normally immune, she needs speedy and effective treatment by the most effective drugs available.

If she is non-immune, she must have regular chemoprophylaxis throughout pregnancy, especially in the last trimester.

CAUTION ! (1) No chemoprophylactic regime is completely effective. If you think she is having a modified attack, treat her. (2) Falciparum infection is especially dangerous during the last trimester.

THE MANAGEMENT OF ANAEMIA Screen all antenatal mothers clinically by examining their conjunctivae and their tongues. If a mother seems anaemic, measure her haemoglobin, and diagnose her as having ''anaemia' if it is [lt]100 g/l. The important symptom is progressive dyspnoea on exertion. Look for: pallor, warm hands, dyspnoea at rest, a collapsing pulse, a large pulse pressure, pulsation of her retinal veins, tachycardia, an ejection systolic murmur (all signs of severe anaemia).

If she is moderately anaemic (60 to 100 g/l), before 34 weeks, investigate her as best you can, and examine a thin blood film. Routine tests for malaria and hookworms are of little value. If sickle-cell disease is common in your area, test for it. Give her tablets of ferrous sulphate three times a day, and folic acid 5 mg daily (this is a larger dose than that in the UNICEF ferrous sulphate/folate tablet) for 3 weeks. This will replace her body folate. Don't give more, and don't give it parenterally. Continue it until delivery. In malarious areas give her a therapeutic antimalarial course, followed by a prophylactic one. If necessary, treat her for hookworms. See her every two weeks in the high-risk clinic, and measure her haemoglobin.

If she is moderately anaemic after 34 weeks, proceed as above, but consider admitting her for parenteral iron and a blood transfusion.

If she is severely anaemic ([lt]60 g/l), admit her, treat as above, and transfuse her if you can.

If she is very severely anaemic (45 g/l or less), or her haemoglobin has has fallen rapidly, watch for these danger signs: Cardiovascular: pulse [mt]120, respirations [mt]24, dyspnoea at rest. Cerebral: mental confusion or coma. Signs that the haemoglobin is falling due to bleeding or haemolysis: bleeding, jaundice, and fever. If she has any of these admit her to the labour ward or an ICU. Nurse her in the half-sitting position. Give her at least 2 units of packed cells and medical treatment as above.

PARENTERAL IRON [s7]FOR ANAEMIA This will not make her haemoglobin rise any faster; it is more expensive, more painful, and may cause reactions. Its only advantage is that it avoids the oral route and the need for her co-operation.

INDICATIONS. Proven iron deficiency anaemia (haemoglobin [lt]60 g/l), in which: (1) oral treatment is unlikely to succeed, or (2) there is not time for it to succeed because she is in the last trimester of pregnancy. And there are no contraindications such as sickle-cell anaemia or some other haemolytic anaemia.

AS A COURSE OF INJECTIONS. Calculate her iron need from her haemoglobin. Give her 150 mg of elemental iron parenterally for every 5 g/l that her haemoglobin needs raising. This will correct the iron deficit in her circulating red cells, with 50% ]]extra to correct her iron stores. A typical dose is 1800 mg. Give her 1 ml (50 mg) the first day, then 2 ml (100 mg) daily or at longer intervals; the maximum daily dose is 5 ml (250 mg). Also give her a 20-day course of 5 mg folic acid tablets by mouth at the same time.

TOTAL DOSE IRON INFUSION (TDI) can supply a patient with all the iron she needs in half a day. But it has risks and can be fatal. A typical indication is the patient who lives far from hospital, can make few antenatal visits, and cannot be admitted. It is contraindicated if she is asthmatic. Give her the iron she needs, calculated as above, in a litre of dextrose slowly over 6 to 8 hours. Give her an antihistamine (promethazine 50 mg) 30 minutes before. For the first 15 minutes, give her 10 drops a minute, then, if all is well, give her the rest of the dose at not more than 1 ml/minute. Expect the maximum effect in 4 to 6 weeks.

CAUTION ! (1) Stop the drip if she has rashes, if her blood pressure falls, her pulse rises, or she has giddiness or rigors. (2) Have adrenalin, aminophylline, and an injectable glucocorticosteroid immediately available. (3) Don't give intravenous iron by bolus intravenous injection. (4) There is some evidence that TDI can make iron available for the metabolism of invading pathogens, increase her susceptibility to infection, and increase the incidence of postnatal malarial parasitaemia, so watch her carefully, and treat her if necessary.

Mr Printer. Please take in the ''not in series' figure ''Blood Bank' somewhere here.

TRANSFUSION [s7]FOR ANAEMIA INDICATIONS. These vary with the risk of HIV:

If there is little or no risk of HIV transfuse her if: (1) She is in incipient cardiac failure with a Hb [lt]40 g/l. (2) She is breathless at rest or needs an operative delivery with a Hb of [lt]60 g/l. One contributor would transfuse all women with a haemoglobin of [lt]60 g/l who are [mt]36 weeks. (3) She has sickle-cell disease and needs an operative delivery with a Hb [lt]80 g/l (transfusion may prevent a sickle-cell crisis). (4) You expect her to lose [mt]1000 ml of blood at operation and her Hb is [lt]80 g/l (500 ml is commonly lost at a normal delivery). (5) She bleeds severely and loses [mt]30% of her blood volume.

If HIV is a risk, only transfuse her to save her life. See Chapter 28a. She is at particular risk if her Hb is [lt]40 g/l, she has twins, or a large spleen, or heart disease, or she needs an operative delivery.

TRANSFUSING RED CELLS. If she has a haemoglobin of less than 60 g/l, give her repeated small transfusions of cells only over several days. You will not be able to centrifuge bottles of blood, so: (1) decant the plasma and transfuse only the packed cells. Or, (2) slowly invert a bottle after you have inserted a giving set. Or, (3) if the blood is in bags, so that decantation is difficult, let them hang upright in a refrigerator to allow the cells fall to the bottom. Open the vent at the top of a bag, squeeze out the plasma by hand, or use a home-made instrument made of two sprung boards. You can then transfuse the packed cells without transfusing most of the plasma.

Don't give her more than 500 ml of packed cells at a time. Add 20 mg of frusemide to 500 ml of packed cells, and transfuse them slowly over 6 hours. Or, precede the transfusion by frusemide 40 mg intravenously. It will cause an intense diuresis, which will reduce her plasma volume, and make room for the packed cells.

If she has rigors or a rise in temperature, stop the drip immediately.

If her pulse pressure or her heart rate rise, they are the earliest signs of cardiac failure, so stop the drip[md]before a rise in her jugular venous pressure and pulmonary oedema make failure obvious. Give her frusemide 40 mg intravenously. Don't repeat it for at least 12 hours.

THE DELIVERY [s7]OF A SEVERELY ANAEMIC PATIENT Premature labour is a common complication of severe anaemia, and may cause heart failure. If her haemoglobin is less than 50 g/l at term, she is an obstetric emergency. A blood ]]transfusion at any stage is often life-saving.

Deliver her sitting up, and give her oxygen if necessary. Don't put up a routine drip[md]it will overload her circulation unnecessarily. Shorten the second stage with a vacuum extractor. Take great care to reduce blood loss. Do an episiotomy only if it is important. Give her ergometrine, or oxytocin, with the third stage. Deliver the placenta actively, using ergometrine and controlled cord traction. Manage any operative procedure with scrupulous asepsis, because she runs an increased risk of puerperal infection. If she loses more than 500 ml transfuse her.

If she is clearly in heart failure, avoid ergometrine and oxytocin (''Syntometrine').

Keep her in the labour ward or the ICU for at least 24 hours after her condition has stabilized. Before you discharge her, warn her to come for antenatal care in her next pregnancy, because she may become anaemic again.

CAUTION ! She can easily go into failure after delivery.

DIFFICULTIES [s7]WITH SEVERE ANAEMIA If, during pregnancy, her ANAEMIA FAILS TO RESPOND to conventional treatment: (1) Is your diagnosis correct? For example, are you really dealing with iron-deficiency anaemia? (2) Is she taking her drugs? (3) Is she continuing to bleed (perhaps hookworms) or to haemolyse (perhaps malaria)?

If she becomes SEVERELY ANAEMIC IN EARLY PREGNANCY, consider the possibility of an ectopic pregnancy.

If she presents with GROSS ANAEMIA DURING THE PUERPERIUM, consider a retained placenta and puerperal sepsis, correct her anaemia, and control infection before you try to remove it.

If she has chloroquine-resistant falciparum malaria (RII), try three tablets of pyrimethamine 25 mg with sufladoxine 500 mg (''Fansidar'). Or, amodiaquine base 600 mg orally once and 400[nd]600 mg daily for two days. If this fails, give her oral quinine 600 mg three times daily for 7 days. If necessary give quinine intravenously 10 mg/kg base over 2[nd]4 hours. Quinine occasionally provokes uterine activity, slows the fetal heart, and causes hypoglycaemia.