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Developmental biology - The Placenta|
Baby's Sex Affects Pregnancy Complications
Mothers pregnant with girls had higher blood levels of a form of spermine compared to mothers pregnant with boys.
Researchers also found the amount of spermine found in mothers pregnant with a girl predicted risk for pregnancy complications in this order:
• High Levels are associated with an increased risk of pre-eclampsia (mother develops high blood pressure and kidney disease)
• Low Levels are associated with an increased risk of poor fetal growth.
The patterns observed were all consistent with previous work which has shown that boys may be more vulnerable to the effects of fetal growth restriction and that being pregnant with a girl may lead to an increased risk of severe preeclampsia.
"In pregnancy and childbirth, the sex of the baby is at the forefront of many parents' minds, we do not even think of the placenta as having a sex.
Preeclampsia and fetal growth restriction (FGR) are major causes of the more than 5 million perinatal and infant deaths occurring globally each year, and both are associated with placental dysfunction. The risk of perinatal and infant death is greater in males, but the mechanisms are unclear. We studied data and biological samples from the Pregnancy Outcome Prediction (POP) study, a prospective cohort study that followed 4,212 women having first pregnancies from their dating ultrasound scan through delivery. We tested the hypothesis that fetal sex would be associated with altered placental function using multiomic and targeted analyses. We found that spermine synthase (SMS) escapes X-chromosome inactivation (XCI) in the placenta and is expressed at lower levels in male primary trophoblast cells, and male cells were more sensitive to polyamine depletion. The spermine metabolite N1,N12-diacetylspermine (DiAcSpm) was higher in the female placenta and in the serum of women pregnant with a female fetus. Higher maternal serum levels of DiAcSpm increased the risk of preeclampsia but decreased the risk of FGR. To our knowledge, DiAcSpm is the first maternal biomarker to demonstrate opposite associations with preeclampsia and FGR, and this is the first evidence to implicate polyamine metabolism in sex-related differences in placentally related complications of human pregnancy.
Sungsam Gong, Ulla Sovio, Irving L.M.H. Aye, Francesca Gaccioli, Justyna Dopierala, Michelle D. Johnson, Angela M. Wood, Emma Cook, Benjamin J. Jenkins, Albert Koulman, Robert A. Casero Jr., Miguel Constância, D. Stephen Charnock-Jones and Gordon C.S. Smith
The work was supported by NIHR Cambridge Biomedical Research Centre and the Medical Council.>
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The genetic profile of the placentas of male and female babies are very different, and affect the
mother and their own grwoth differently. Image: Gordon Smith, University of Cambridge, UK