Limited Impact of Fetal Sex and Maternal Body Mass Index on Fetal and Maternal Insulin Resistance and Lipid Metabolism: Findings from the PEARs Study
The intrauterine environment can have a significant impact on fetal and maternal well-being, both during pregnancy and in later life. We aimed to identify how fetal sex and maternal body mass index (BMI) influence insulin resistance and metabolic function during pregnancy with maternal BMI > 25 kg/m2. This secondary analysis assessed data from the PEARS–randomized controlled trial that recruited pregnant women with body mass indexes 25–39.9 kg/m2. Longitudinal measurements of maternal and fetal insulin resistance and metabolic function were recorded throughout pregnancy. Regression models tested the effects of fetal sex and maternal BMI on markers of metabolic function and insulin regulation. A total of 484 women and their newborns (252 (52%) males vs. 232 (48%) females) were included in the analysis. A total of 333 (69%) women were overweight and 151 (31%) were obese. Male newborns were heavier and larger than females, and had a higher rate of instrumental delivery. Males had a lower LDL, but no other markers of insulin resistance or metabolic function were affected by fetal sex. Women with obesity had elevated markers of insulin resistance and metabolic dysfunction compared with women that were overweight, but maternal BMI did not impact these variables in the fetus. Fetal sex did not impact maternal and fetal metabolic parameters in women with BMI > 25 kg/m2. However, a higher BMI caused increasingly deranged maternal blood lipid concentrations and markers of insulin resistance as pregnancy progressed. Lipid monitoring and interventions to reduce lipids during pregnancy therefore require further evaluation.
KeywordsBody mass index Fetal Insulin resistance Lipids Maternal
The authors wish to acknowledge and thank the mothers who participated in the PEARS study in the National Maternity Hospital.
This research was supported by the National Maternity Hospital medical fund.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
This study presents a secondary analysis of the PEARS database, which was a single-centred–randomised controlled trial conducted at the National Maternity Hospital, Dublin, with institutional ethical approval. The trial was registered as ISRCTN29316280.
Statement of Informed Consent
Full written, informed consent was obtained from all participants.
- 6.Sonagra AD, Biradar SM, Dattatreya K, Jayaprakash Murtha DS. Normal pregnancy - a state of insulin resistance. Journal of Clinical & Diagnostic Research. 2014;8(11):CC01–C3.Google Scholar
- 19.Institute of Medicine and National Research Council Committee to Reexamine IOMPWG. The National Academies Collection: Reports funded by National Institutes of Health. In: Rasmussen KM, Yaktine AL, editors. Weight gain during pregnancy: reexamining the guidelines. Washington (DC): National Academies Press (US) National Academy of Sciences; 2009.Google Scholar
- 20.International Association of Diabetes Pregnancy Study Groups Consensus Panel, Metzger BE, Gabbe SG, Persson B, Buchanan TA, Catalano PA, et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care. 2010;33(3):676–82.CrossRefGoogle Scholar
- 29.Lipschuetz M, Cohen SM, Ein-Mor E, Sapir H, Hochner-Celnikier D, Porat S, et al. A large head circumference is more strongly associated with unplanned cesarean or instrumental delivery and neonatal complications than high birthweight. Am J Obstet Gynecol. 2015;213(6):833 e1- e12.CrossRefGoogle Scholar