What is the effectiveness of antenatal care? (Supplement)

Summary

The issue

Antenatal Care (ANC) means “care before birth”, and includes education, counselling, screening and treatment to monitor and to promote the well-being of the mother and foetus. The current challenge is to find out which type of care and in what quantity is considered sufficient to ensure good quality of care for low-risk pregnant women. Only interventions of proven effectiveness, for which benefits largely overcome possible harms, and those acceptable to pregnant women and their families, should be offered.

This report is a supplement to the 2003 HEN synthesis report. It is a review of the best available evidence in the scientific literature regarding ANC interventions. It identifies evidence on effective ANC interventions, as well as on those that are not effective but still used, perhaps because of tradition. Additionally, it identifies interventions whose effectiveness is still unknown.

The findings

Evidence-based effective interventions for ANC include:

• antenatal education for breast feeding;
• energy/protein supplementation in women at risk for low birth weight;
• folic acid supplementation to all women before conception and up to 12 weeks of gestation to avoid neural tube defects in the foetus;
• iodine supplementation in populations with high levels of cretinism;
• calcium supplementation in women at high risk of gestational hypertension and in communities with low dietary calcium intake;
• smoking and alcohol consumption cessation for reducing low birth weight and preterm delivery;
• acupressure (sea bands) and ginger for nausea control;
• bran or wheat fibre supplementation for constipation;
• exercise in water, massages and back care classes for backache;
• screening for pre-eclampsia with a comprehensive strategy including an individual risk assessment at first visit, accurate blood pressure measurement, urine test for proteinuria and education on recognition of advanced pre-eclampsia symptoms;
• anti-D given during 72 hours postpartum to Rh-negative women who have had a Rh-positive baby;
• Down’s syndrome screening;
• screening and treatment of asymptomatic bacteriuria during pregnancy;
• screening of hepatitis B infection for all pregnant women and delivery of hepatitis B vaccine and immunoglobulin to babies of infected mothers;
• screening for HIV in early pregnancy, a short course of antiretroviral drugs, and caesarean section for infected mothers at 38 weeks, to reduce vertical transmission;
• screening for rubella antibody in pregnant women and postpartum vaccination for those with negative antigen;
• screening and treatment of syphilis;
• routine ultrasound early in pregnancy (before 24 weeks);
• external cephalic version at term (36 weeks) by skilled professionals, for women who have an uncomplicated singleton breech pregnancy; and
• a course of corticosteroids given to women at risk of preterm delivery to reduce respiratory distress syndrome in the baby and neonatal mortality.

Sexual intercourse and moderate aerobic exercise have been found safe during pregnancy.

Antenatal care from midwives or general practitioners in low-risk pregnancies is cost-effective. A model of ANC with a restricted number of visits for low-risk women has been shown to be safe, more sustainable, and possibly as effective as models with higher number of visits.

While for some interventions there is clear evidence of effectiveness or ineffectiveness, for many there is still uncertainty due to a lack of well-conducted randomized trials.

Policy considerations

• ANC is a right for any pregnant women. Therefore interventions proved effective in the scientific literature should be provided universally, free of charge.
• The package of interventions included in routine ANC should be based on effectiveness; local epidemiology of specific diseases in each country, local priorities and resources; and the preferences and values of recipients.
• The model of care developed by WHO seems the best evidence-based package for low-risk pregnant women. Continuous ANC from a midwife seems to be the most cost-effective way to provide this type of care.
• There are still interventions of unproven effectiveness in use. More research in these areas is needed.

Type of evidence

Interventions whose effectiveness has been assessed through systematic reviews (SR) of randomized or quasi-randomized controlled trials (RCT) were included. Priority was given to RCT, but observational studies were also included when needed. This document is a technical supplement to the 2003 HEN report.