Maternal serum alpha-fetoprotein in twin pregnancy.
Maternal serum alpha-fetoprotein concentration was measured at 14 to 20 weeks' gestation in 138 twin pregnancies. All patients had at least one ultrasonographic examination (86% before 20 weeks' gestation). Two pregnancies were discordant for open fetal defects (one anencephaly, one gastroschisis). The median serum alpha-fetoprotein value in the remaining 136 twin pregnancies paralleled a curve 2.5 times the median curve for singleton pregnancies over the gestational range studied. Higher serum alpha-fetoprotein values correlated significantly with increasing incidence of fetal and neonatal death, premature delivery (less than 35 weeks' gestation), and twin-to-twin birth discordance (greater than 20%), most pronounced at greater than 4 multiples of the singleton median level. A significant negative correlation between alpha-fetoprotein and birth weight was observed (p less than 0.001), but was related more to prematurity than to poor fetal growth. Theoretically, serum alpha-fetoprotein screening detected 56.5% of the twins in this study when a cutoff level of 2.5 multiples of the median was used, enhancing twin detection in the study population by 40%. These data indicate that maternal serum alpha-fetoprotein screening has a valuable role in the management of twin pregnancy, both in the detection of twins and in the prediction of perinatal outcome in twin pregnancy.
Johnson
J M
JM
Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Manitoba, Winnipeg, Canada.
Harman
C R
CR
Evans
J A
JA
MacDonald
K
K
Manning
F A
FA
D005260:Female; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000097:blood*; D012016:Reference Values; D014427:Twins; D000509:alpha-Fetoproteins / Q000032:analysis*
D000509:alpha-Fetoproteins