The Heavy Burden: How Obesity Compounds Fertility and Pregnancy Risks – ARC Summit

The Nurses’ Health Study from 2002 highlighted the direct correlation between BMI and ovulatory infertility, showing a nearly exponential increase in risk as BMI rises. This study underscores the complex, multifactorial impact of obesity on fertility, affecting egg quality, steroidogenesis, mitotic spindle formation, and mitochondrial function in oocytes. Moreover, obesity complicates the receptivity of the placenta, adding to infertility challenges.

The pathophysiology behind these issues is intricate and not entirely understood, but it is evident that obesity interferes with several reproductive processes, including follicular recruitment, development, fertilization, and implantation. Beyond conception difficulties, obesity significantly increases maternal risks during pregnancy. Women face heightened risks of miscarriage, venous thromboembolism, gestational diabetes, preeclampsia, labor complications, cesarean delivery, wound complications, anesthetic challenges, and even maternal mortality. The relationship between increased BMI and these complications is clear and concerning.

For the fetus, the risks are equally severe. Obesity in mothers is linked to a higher likelihood of congenital abnormalities, fetal macrosomia, shoulder dystocia, stillbirth, neonatal death, and intensive care admissions post-birth. These risks underscore the critical nature of managing weight before and during pregnancy to ensure both maternal and fetal health.

Furthermore, insulin resistance emerges as a pivotal factor in obesity-related fertility issues, particularly in polycystic ovary syndrome (PCOS). Elevated insulin levels can exacerbate androgen production by the ovaries, leading to disrupted ovulation and increased testosterone levels, which are pivotal in the pathogenesis of infertility. High levels of triglycerides and fatty acids, common in insulin-resistant states, further contribute to this disruption, compounding the challenges faced by obese individuals in achieving and maintaining a healthy pregnancy. This complex interplay of metabolic, hormonal, and reproductive dysfunctions makes managing obesity crucial for those seeking fertility treatments and successful outcomes in pregnancy.