|03. What Is the Evidence for the Role of Antenatal Care Strategies in the Reduction of Maternal Mortality and Morbidity?|
When discussing prevention, a scrutiny of the causes, and in the present context the part played by antenatal care, is paramount.
Haemorrhage may arise at any time during pregnancy, birth and puerperium. Causes differ, and hence the possibility for their prevention. Acute bleeding will commence before or between routine antenatal care visits and as a rule requires emergency consultation. Bleeding due to spontaneous early abortion is generally self-limiting. Major separation of the placenta is life-threatening, because of acute blood loss and later coagulopathy. Patients with placenta previa are also at high risk and in any case need constant surveillance. Proper antenatal care can lead to the earlier diagnosis of placenta previa, and management according to modern principles can reduce maternal mortality. Referral to second or third level centres for sonographic investigation is mandatory. Education may induce women to seek medical care when they start bleeding in late pregnancy. This education should ideally also be given to husbands, friends or other family members. Advice and counselling are therefore key elements which may help women secure rapid hospital treatment. Previous blood group typing may save blood matching time in emergency situations. Certain individual risk factors should induce more intensive monitoring: history of haemorrhage or coagulopathy in previous pregnancy, grand multiparity, polyhydramnios, hypertensive disease of pregnancy and premonitory bleeding in the present pregnancy.
Anaemia will aggravate the effects of bleeding, and iron prophylaxis should be considered in areas of high anaemia prevalence. This will reduce the proportion of women with low Hb levels and the need of blood transfusions post partum, but trials have not been shown to effect maternal, perinatal and long-term outcomes (see Villar & Bergsjø 1997).
Puerperal sepsis is more prevalent in places with high maternal mortality, mainly due to unclean home deliveries, higher rates of pathogenic genital tract infections and poor cleanliness and delay after rupture of the membranes. The main preventive effort is to secure clean delivery, as advised in the Mother-Baby Package (World Health Organization 1994). The role of antenatal care is mainly educational, with emphasis on cleanliness and the need to seek care in case of spontaneous pre-term rupture of the membranes. Screening for bacteriuria with adequate treatment if positive is a way to possibly eliminate one focus of infection, but its effectiveness in low-income settings in third world countries is far from established (Olsen et al . 2000). Other possibilities for prevention of tetanus and other specific infections are outlined in Table 3. A WHO report from 1991 is still a good source of information (World Health Organization 1991).
Preeclampsia will be diagnosed by blood pressure measurement and detection of protein in the urine. Routine weight recording does not add to the diagnostic accuracy. The rationale behind the increasing frequency of visits in the standard antenatal care programmes was to detect preeclampsia as early as possible, but none of the trials testing schedules of fewer visits have shown any differences for detection and outcome complications of preeclampsia. Those at high risk should be followed more closely or referred to higher level of care (very young primigravidae, those with preeclampsia or eclampsia in previous pregnancies. Eclampsia may strike without prior signs of preeclampsia. All pregnant women and their partners (or sisters and mothers) should be told about early signs and how to react. It remains to be demonstrated that antenatal care leads to improved survival when hypertensive disorders are concerned (Rooney 1992).
Obstructed labour by definition manifests itself at birth. The best predictor is obstructed labour during the previous delivery. For primigravidae, maternal height has been used to select those of low stature for hospital delivery and is still useful in places where one has to select cases for hospital delivery. The test sensitivity is low but obviously increases with decreasing cut-off levels of height. Serial measurements of symphysis-to-fundus distance will detect those with large foetuses and will help select those in special need of caesarean section.
Deaths due to unsafe abortion occur all over the world, with notable exceptions for North America and most parts of Europe where abortion is legal, safe and relatively accessible (World Health Organization 1997). This problem must be attacked at parliamentary and governmental levels, all one can give at antenatal care is education about family planning and the dangers of abortion.