To assess the influence of in vitro fertilization (IVF) on maternal se
rum human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP), t
he maternal serum hCG and AFP values were studied in 67 IVF pregnancie
s and compared with the results of a control group of 4732 spontaneous
ly conceiving patients. Maternal serum hCG was significantly higher an
d AFP significantly lower in the IVF group. Possible explanations and
implications for prenatal diagnosis in IVF pregnancies are discussed.