Maternal serum alpha‐fetoprotein and fetal sex

Risk of abnormal triple screen for Down syndrome is significantly higher in patients with female fetuses

“…Since the frequency of female fetuses among trisomy 21 cases is actually lower than among euploids (Mutton et al, 1996), and the rates of female and male Down syndrome fetuses detected by triple screen and subsequent amniocentesis are not significantly different (Ghidini et al, 1998), the increased frequency of abnormal triple screen among female fetuses is likely due to a higher false-positive rate. Similar to our results, gender-related differences in maternal serum AFP at triple screen have been reported by other investigators as well (Calvas et al, 1990;Sowers et al, 1983;Petrikovsky, 1989;Lockwood et al, 1993). A consistent finding in all studies is that the fetal genderrelated differences in maternal analytes occur in the direction of yielding abnormal triple-screen results among women with female fetuses.…”

“…A positive triple screen for Down syndrome is characterized by low MoM values for AFP and uE3, and high values for hCG. However, fetal sex affects maternal serum AFP and hCG values: lower AFP levels (Sowers et al, 1983;Petrikovsky, 1989;Calvas et al, 1990;Lockwood et al, 1993) and higher hCG levels (Leporrier et al, 1992) have been reported in women with euploid female than in those with euploid male fetuses. The objective of this study was to evaluate if women with female fetuses are at greater risk of having a positive triple-screen result for Down syndrome.…”

Are Amniotic Fluid Alpha-Fetoprotein Levels Influenced by the Gender in Twin Pairs?

“…Also, there were several studies demonstrating lower maternal serum AFP (MSAFP) levels in pregnant women with female fetuses, as compared to male fetuses [7][8][9]. MSAFP levels are affected by AFAFP levels and by maternal and placental factors.…”

Is maternal serum triple screening a better predictor of Down syndrome in female than in male fetuses?

“…In particular, mothers of female fetuses have been reported to have significantly lower MSAFP and higher hCG levels than those of male fetuses (Sowers et al, 1983;Wald and Cuckle, 1984;Petrikovsky, 1989;Calvas et al, 1990;Lockwood et al, 1993;Leporrier et al, 1992;Szabó et al, 1995). As a consequence, there is a small preponderance of female false-positive results (i.e., female euploid fetuses) among women undergoing amniocentesis because of abnormal MSAFP and hCG results (Petrikovsky, 1989;Leporrier et al, 1992).…”