Sexual origins of placental dysfunction.

Lancet · 2000

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Abstract

Severe placental dysfunction is much more common in pregnancies with a male than with a female fetus. Furthermore, the birthweight/placental weight ratio is increased in these pregnancies, consistent with fetal growth restriction, and is higher with a male fetus than with a female fetus. These observations of placental insufficiency may underlie the increased in-utero loss rate of male fetuses.