Results and benefits of a maternal serum alpha-fetoprotein screening program
A. Milunsky and E. Alpert
Maternal serum alpha-fetoprotein (MSAFP) screening was offered in a private
suburban practice to 21,000 nondiabetic and 442 diabetic women with
apparently normal pregnancies. Using 2.5 or greater multiples of the median
as the normal upper limit, 249 (1.2%) had a raised MSAFP level. There were
25 neural tube defects (NTDs) (1.2/1,000 births); 18 were detected by
screening and two by ultrasound scanning. Three had closed spina bifida
lesions. Two had anencephaly with normal MSAFP levels, but were studied at
more than 24 weeks' gestation. An additional 13 with raised MSAFP levels
had other congenital defects. One in 400 women screened had a recommended
amniocentesis; 26.4% of them had a fetus with an NTD or major malformation.
Our detection efficiency before 24 weeks' gestation for anencephaly was
85.7% (12/14), 62.5% (5/8) for open and closed spina bifida, and 1/1 for
encephalocele. A raised MSAFP level occurred in ten (2.3%) of the 442
diabetic women, four (0.9%) of whom had a fetus with an open NTS. A
screening program should be established only where there is linked
excellent interdisciplinary support among obstetrician, laboratory,
clinical geneticist, ultrasonographer, and an identified program
coordinator.
