The Genetic Impact of Basal Metabolic Rate on Pregnancy Complications: A Mendelian Randomization Study

Objectives: As an indicator of an individual's energy metabolism at rest，the basal metabolic rate (BMR) has been demonstrated to be linked to the onset and progression of various diseases. However, the relationship between BMR and pregnancy complications remains unkown. The present study aimed to explore the causal relationship between BMR and pregnancy complications through the application of Mendelian randomization(MR) analysis. Methods: We identified a range of complications that can arise throughout pregnancy as our objects and obtain the instrumental variables of BMR and pregnancy complications in genome-wide association studies (GWAS). The causal association between BMR and these complications was assessed using a two-sample MR analysis. Additionally, sensitivity analyses were conducted to ascertain the robustness and reliability of results. And multivariate Mendelian randomization(MVMR) analysis was employed to mitigate the impact of potential confounders. Results: A higher BMR is significantly associated with an elevated risk of gestational hypertension, preeclampsia or eclampsia, and postterm pregnancy. Conversely, a lower BMR was found to be significantly associated with an increased risk of preterm birth, Hyperemesis Gravidarum, and dystocia due to pelvic narrowing .In reverse MR analysis,we did not identify any significant causal impact of pregnancy complications on BMR. Furthermore, MVMR analysis confirmed that the associations between BMR and gestational hypertension, preterm birth, and dystocia due to pelvic stenosis were independent of potential confounding factors.Conclusions: This investigation is the first to highlight the correlation between BMR and pregnancy complications. The maintenance of BMR balance may contribute to the improvement of pregnancy outcomes, offering a novel theoretical foundation and practical guidance for health management during pregnancy.