The significance of raised maternal plasma alpha-fetoprotein in twin pregnancy.

A hundred twin pregnancies were examined before 27 weeks gestation. The level of maternal plasma alpha-fetoprotein (AFP) was correlated with outcome of the pregnancy. Forty per cent of all women had elevated plasma AFP levels. At birth the combined infant weights were greater in the women with elevated AFP; the gestational age at delivery was unrelated to the level of AFP in early pregnancy.