Fetal sex and maternal pregnancy outcomes

a systematic review and meta-analysis


<p>BACKGROUND: Since the placenta also has a sex, fetal sex-specific differences in the occurrence of placenta-mediated complications could exist.</p><p>OBJECTIVE: To determine the association of fetal sex with multiple maternal pregnancy complications.</p><p>SEARCH STRATEGY: Six electronic databases Ovid MEDLINE, EMBASE, Cochrane Central, Web-of-Science, PubMed, and Google Scholar were systematically searched to identify eligible studies. Reference lists of the included studies and contact with experts were also used for identification of studies.</p><p>SELECTION CRITERIA: Observational studies that assessed fetal sex and the presence of maternal pregnancy complications within singleton pregnancies.</p><p>DATA COLLECTION AND ANALYSES: Data were extracted by 2 independent reviewers using a predesigned data collection form.</p><p>MAIN RESULTS: From 6522 original references, 74 studies were selected, including over 12,5 million women. Male fetal sex was associated with term pre-eclampsia (pooled OR 1.07 [95%CI 1.06 to 1.09]) and gestational diabetes (pooled OR 1.04 [1.02 to 1.07]). All other pregnancy complications (i.e., gestational hypertension, total pre-eclampsia, eclampsia, placental abruption, and post-partum hemorrhage) tended to be associated with male fetal sex, except for preterm pre-eclampsia, which was more associated with female fetal sex. Overall quality of the included studies was good. Between-study heterogeneity was high due to differences in study population and outcome definition.</p><p>CONCLUSION: This meta-analysis suggests that the occurrence of pregnancy complications differ according to fetal sex with a higher cardiovascular and metabolic load for the mother in the presence of a male fetus.</p><p>FUNDING: None.</p>

Reference Broere-Brown, Z. A., Adank, M. C., Benschop, L., Tielemans, M., Muka, T., Gonçalves, R., Bramer, W. M., Schoufour, J. D., Voortman, T., Steegers, E. A. P., Franco, O. H., & Schalekamp-Timmermans, S. (2020). Fetal sex and maternal pregnancy outcomes: a systematic review and meta-analysis. Biology of sex differences, 11, 26. Article 26. https://doi.org/10.1186/s13293-020-00299-3
Published by  Urban Vitality 11 May 2020

Publication date

May 2020


Zoe A Broere-Brown
Maria C Adank
Laura Benschop
Myrte Tielemans
Taulant Muka
Romy Gonçalves
Wichor M Bramer
Trudy Voortman
Eric A P Steegers
Oscar H Franco
Sarah Schalekamp-Timmermans


Research database