Male-to-female gender ratio in fetuses with increased nuchal translucency

Abstract

More males than females had mild NT enlargement on first-trimester screening, but unless aneuploidy was detected they had normal birth outcomes. A slightly larger NT may be normal in males, while indicating possible fetal abnormalities in females.

The significance of gender in fetuses with increased nuchal translucency: pregnancy outcomes and long‐term outcomes of children

“…The larger of these studies included 581 fetuses with NT ≥95th percentile and they showed euploid male fetuses with increased NT to have almost twofold better prognosis than female fetuses especially in the group of only mildly increased NT (95th percentile – 3.5 mm) . It was shown that the male‐to‐female ratio was higher when the NT was only mildly increased (95th percentile – 3.5 mm), and the conclusion was that a mild increase could be a normal variant in male fetal development . In our study, which included only fetuses with increased NT, the NT thickness of female fetuses was higher compared with that of male fetuses, and the difference became significant when the NT was ≥3.1 mm.…”

“…7 It was shown that the male-tofemale ratio was higher when the NT was only mildly increased (95th percentile -3.5 mm), and the conclusion was that a mild increase could be a normal variant in male fetal development. 7,18 In our study, which included only fetuses with increased NT, the NT thickness of female fetuses was higher compared with that of male fetuses, and the difference became significant when the NT was ≥3.1 mm. This difference was explained by aneuploid female fetuses having thicker NT compared with aneuploid male fetuses.…”

“…The largest of these studies by Cowans et al showed a 9.41% decrease in delta NT for female fetuses compared with male fetuses in a population of 56 024 normal pregnancies . In two studies, the gender impact on fetuses with increased NT was assessed . The larger of these studies included 581 fetuses with NT ≥95th percentile and they showed euploid male fetuses with increased NT to have almost twofold better prognosis than female fetuses especially in the group of only mildly increased NT (95th percentile – 3.5 mm) .…”

“…[14][15][16][17] Evidence shows that the situation could be opposite among fetuses with increased NT. 7,18 Several studies show that the NT in unselected or normal population is thicker among male fetuses compared with that of female fetuses. 1,[4][5][6][7][8][9] The largest of these studies by Cowans et al showed a 9.41% decrease in delta NT for female fetuses compared with male fetuses in a population of 56 024 normal pregnancies.…”

“…5 In two studies, the gender impact on fetuses with increased NT was assessed. 7,18 The larger of these studies included 581 fetuses with NT ≥95th percentile and they showed euploid male fetuses with increased NT to have almost twofold better prognosis than female fetuses especially in the group of only mildly increased NT (95th percentile -3.5 mm). 7 It was shown that the male-tofemale ratio was higher when the NT was only mildly increased (95th percentile -3.5 mm), and the conclusion was that a mild increase could be a normal variant in male fetal development.…”