The mediating role of placenta in the relationship between maternal exercise during pregnancy and full-term low birth weight

Abstract

Objective: To explore the association of maternal exercise during pregnancy with full-term low birth weight (FT-LBW) and whether placenta mediates their association.

Study design: We investigated 326 pregnant women delivering FT-LBW weight newborns (cases) and 1644 delivering full-term normal birth weight newborns (controls) in this case-control study. Information concerning maternal exercise during pregnancy, socio-demographics and obstetric characteristics were collected at Women and Children’s Hospitals of Shenzhen and Foshan in Guangdong, China.

Results: After adjusting for the potential confounders, maternal exercise frequency and duration during pregnancy were significantly negatively associated with FT-LBW, respectively. Moreover, compared with mothers taking no exercise during pregnancy, those taking exercises were significantly negatively associated with FT-LBW except those taking low/medium frequency and short duration exercise and high-frequency and long duration exercise, and their adjusted ORs ranged from 0.30 to 0.62. Furthermore, mediation analysis illustrated that placental weight partially mediated 27.20% of the association between maternal exercise frequency during pregnancy and FT-LBW, but not the association between maternal exercise duration during pregnancy and FT-LBW.

Conclusions: Maternal exercise during pregnancy is beneficial for lowering FT-LBW risk, especially when taking appropriate and enough exercise. Placenta weight partially mediates the association between maternal exercise frequency during pregnancy and FT-LBW.

Keywords:

• Case-control study
• full-term low birth weight
• maternal exercise during pregnancy
• placental weight

Acknowledgements

This study was supported by the National Natural Science Foundation of China (Grant No. 30872164 and 81172758). The authors acknowledge the support of the Shenzhen Women and Children’s Hospital and the Foshan Women and Children’s Hospital.

Disclosure statement

The authors have no conflicts of interest to declare.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China (Grant No. 30872164 and 81172758).