The effect of fetal gender on the prediction of Down syndrome by means of maternal serum α-fetoprotein and ultrasonographic parameters

2nd-Trimester Maternal Serum Human Chorionic Gonadotropin and α-Fetoprotein Levels in Male and Female Fetuses with Down Syndrome

“…Santolaya-Forgas et al [6] showed that in patients with low 2nd-trimester hCG levels, there was a preponderance of male fetuses. Other studies [4][5][6][7][8][9][10][11] have also shown that in women carrying female fetuses, the maternal serum hCG level is higher as compared with those carrying male fetuses. In contrast, the MSAFP level is lower in the presence of a female fetus [7-9, 11-14, 17] .…”

“…These levels were expressed as gestational-age-corrected multiples of the median. Results: No statistically signifi cant differences were noted in maternal serum levels of hCG or AFP in DS pregnancies between women carrying a female and those carrying a [4][5][6][7][8][9][10][11][12][13][14][15] . In fact, the gender-related difference in maternal serum hCG level has been demonstrated as early as the 3rd week after fertilization [16] .…”

Fetal gender and maternal serum screening markers

“…Although results from several studies have suggested that fetal gender may have an effect on the maternal serum concentration of pregnancy-related products, [1][2][3][4][5][6][7][8] we could not find a controlled study in which clinical confounding variables that may affect the concentration of maternal serum screening markers for chromosomal and pregnancy complications had been excluded from analysis before the evaluation of the possible effect of fetal gender. For this reason, we performed a nested study in which the clinical records of 213 pregnant women who had consented to donate blood for biochemical research purposes during pregnancy were reviewed in a protocol approved by the institutional review board of Texas Tech University.…”

No Effect of Fetal Sex on Amniotic Fluid Alpha-Fetoprotein

“…The reported [1][2][3][4] higher alphafetoprotein levels in maternal serum in pregnancies with a male fetus is probably the result of some modification of alpha-fetoprotein transfer into the maternal circulation, possibly mediated by fetal sex.…”

“…Fetal sex has been noted to affect alpha-fetoprotein concentration in maternal serum -significantly higher alpha-fetoprotein levels have been reported in pregnan cies with a male fetus [1][2][3][4], This effect, which is appar ently true in both the second and the third trimesters [2,3], is not correlated with parity, maternal age, maternal weight or weight gain or with fetal weight [3], Higher alpha-fetoprotein levels in the serum of gravi das carrying a male fetus may result either from sex-spe cific hormonal influences on transcription of the alpha- This article is also accessible online at: http:// www. karger, ch http://BioMedNct.com / karger fetoprotein gene (increased production) or from increased transfer of alpha-fetoprotein into the maternal circulation in male gestations.…”