Scientific basis for the content of routine antenatal care. II. Power to eliminate or alleviate adverse newborn outcomes; some special conditions and examinations

Abstract

Background: There is uncertainty concerning antenatal care as a tool to eliminate or alleviate adverse outcomes in the newborn. We identified congenital conditions, intrauterine infections, intrauterine growth retardation, preterm birth and some specific infectious diseases in the mother with a view to prophylactic and other interventions. The value of some special diagnostic tools is also under discussion.

Methods: Review of recent literature, especially randomized controlled trials and systematic reviews.

Results and conclusions: Genetic abnormalities cannot be prevented after conception, but many of them, and a number of acquired conditions, can be discovered by ultrasonographic and biochemical diagnostics. The advisability of screening must be determined locally for each condition, based on prevalence, treatment options and the legal requirements for abortion. Smoking, excessive alcohol intake, and severe undernutrition cause fetal growth retardation. Interventions to reduce maternal smoking have had limited success. Protein-energy supplementation only modestly affects birthweight. Routine measurement of uterine height is a good predictor of severe growth retardation and in rural settings of perinatal death. Preterm birth has been linked to ascending infection and subsequent rupture of the membranes. Attempts to eradicate local infections have shown some benefit but results are not convincing yet. Cervical cerclage and betamimetic drugs have little, if any, effect. Claims for reduction of physical strain (standing > 5 hours) at work should be supported. Tuberculosis in the mother should be discovered and treated. Malaria prophylaxis during pregnancy will protect the mother and possibly benefit the fetus. Adequate tetanus immunization of all mothers is a high priority intervention in developing countries. In HIV-positive mothers, Zidovudine ante- and perinatally will lower perinatal HIV-transmission significantly. Risk scoring may help identify some women for referral to higher level of care. Routine ultrasonography does not improve the outcome of pregnancy in terms of live births and morbidity, but may influence mortality through discovery and abortion of fetuses with major malformations. One vaginal examination during pregnancy is recommended but no repeat procedure unless medically indicated.