NO EFFECT OF FETAL SEX ON AMNIOTIC-FLUID ALPHA-FETOPROTEIN

Objective: To evaluate the effect of fetal sex on the concentration of amniotic fluid alpha-fetoprotein (AF-AFP) in singletons and twins. Ma terial and Methods: Amniocentesis was performed for advanced maternal age between 15 and 20 weeks of gestation. Only patients with normal ka ryotypes, uncomplicated gestations and normal ultrasound examination w ere included. AFP was measured in amniotic fluid by RIA and results, e xpressed as multiples of the median (MoM), were grouped according to f etal sex and were compared by t test. Results: A total of 603 singleto n pregnancies (294 females and 309 males) and 45 twin pregnancies disc ordant for sex met the inclusion criteria. The mean AF-AFP in singleto n males was 1.06 vs. 1.04 MoM in singleton females. In twins, the mean AF-AFP was, respectively, 1.05 and 1.07 MoM (p > 0.05). Conclusion: G ender had no impact on AF-AFP in singleton or twin pregnancies, sugges ting that the differential influence of sex hormones on the activity o f the AFP gene is negligible.