[Biochemical screening for fetal abnormalities - alpha-fetoprotein.].

The use of maternal serum alpha-fetoprotein (MSAFP) in screening for open neural tube defects and other fetal abnormalities is discussed. The arguments for the introduction of this screening test in certain areas of Iceland are provided and its possible application. MSAFP could be used as part of the triple test used for the screening of chromosomal abnormalities at 15-18 weeks of pregnancy, or as a single marker for neural tube defects.

[Amniocenteses and chorion villus biopsies to diagnose fetal karyotyping.].

In this article amniocenteses and chorion villus biopsies are reviewed. The technique is described for both procedures and any side effects discussed, both immediate and possible long term effects. The procedures are compared in terms of timing during pregnancy, complication rates and accuracy of test results.

[Prevalence and diagnosis of neural tube malformations in Iceland 1972-1991.].

OBJECTIVE: The incidence and types of central nervous system (CNS) defects diagnosed in fetuses and newborns over a 20-year period, 1972-1991, were investigated. Concurrently the effect of prenatal ultrasound screening on the rates of delivered babies with neural tube defects were evaluated. MATERIAL AND METHOD: All CNS defects diagnosed in newborn babies and in miscarried or legally aborted fetuses in Iceland during the study period were searched for using the Icelandic Birth and Abortion Registries. For ascertainment maternity case records, hospital records and autopsy and pathology reports were scrutinized. The number and types of defects were noted for each year and the prevalence evaluated for five- and 10-year periods as well as for the time after introduction of organised obstetric ultrasound screening. RESULTS: There was considerable yearly variation in the incidence of CNS defects. In the first five-year period no CNS defect was diagnosed prenatally, but thereafter the number of cases diagnosed before birth rose, partly because of improved identification of more subtle defects. In spite of an increase in the number of cases to 2.2/1000 births, the incidence of babies born with CNS defects was more than halved to 0.8/1000 births. Organised nationwide ultrasound screening in and after 1984 had a marked lowering effect on the number of births with these defects. In 60% of cases the diagnosis was obtained before birth, most often before 22 weeks gestation. Most severe malformations were diagnosed, except for spina bifida, where after 1984 only 40% were diagnosed early enough to allow termination of pregnancy. CONCLUSION: The incidence of CNS defects has risen, probably because of improved recognition of these malformations during pregnancy and to some extent after birth. Organised obstetric ultrasound allowed diagnosis of most severe defects, although 1/3 of defects leading to severe handicap went undiagnosed until after birth, particularly in smaller hospitals and health centers outside Reykjavik. Improving the diagnostic possibilities through training of staff handling obstetric screening is important, but the introduction of nationwide biochemical screening must also be considered.

A randomised double blind placebo controlled trial of fish oil in high risk pregnancy.

OBJECTIVE: To determine whether n-3 fatty acid (EPA/DCHA) prophylaxis is beneficial in high risk pregnancies. DESIGN: A randomised, double blind, placebo controlled trial. SETTING: Antenatal clinic of St James's University Hospital, Leeds. SUBJECTS: Two hundred and thirty-three pregnant women at high risk of developing proteinuric or nonproteinuric pregnancy induced hypertension or asymmetrical intrauterine growth retardation. INTERVENTION: Active treatment was 2.7 g of MaxEpa daily (1.62 g of eicosapentaenoic acid and 1.08 g of docosahexaenoic acid). Placebo were matching air-filled capsules. MAIN OUTCOME MEASURES: Occurrence of proteinuric, nonproteinuric pregnancy induced hypertension or birthweight < 3rd centile. RESULTS: There was no difference in an intention to treat analysis between the placebo and active treatment groups for occurrence of proteinuric pregnancy induced hypertension (relative risk (RR) = 0.88; 95% CI 0.47-1.66), nonproteinuric pregnancy induced hypertension (RR = 0.89; 95% CI 0.48-1.64), birthweight < 3rd centile (RR = 0.89; 95% CI 0.48-1.64), or the duration of pregnancy (difference of mean durations = 0.1 days; 95% CI -4.8 to 4.9 days). Analyses stratified by use of tobacco, and analyses excluding known major protocol violators gave essentially identical results. CONCLUSION: There is no evidence from this study for any useful effect of fish oil supplementation for women at high risk of adverse outcomes from a pregnancy, but a small protective effect remains a possibility.