The general health implications of maintaining normal weight have long been understood. More recently, studies have given us a better understanding of the effects of weight on fertility .Both underweight and overweight women and men suffer from a higher incidence of infertility.
Adipose tissue is an active endocrine organ; in obese women, leptin is increased and adiponectin is decreased, leading to increased insulin resistance. Androgen levels may also be increased. These changes are associated with anovulation (failure of the ovary to release ova over a period of time)
There are numerous potential complications for obese women trying to get pregnant through IVF technology. Some of these include:
- Lower response to medication used to regulate or initiate ovulation.
- Greater need for carefully titrated dosing of medication, especially in patients with polycystic ovaries.
- Greater risk of multiple pregnancies in response to medications used to induce ovulation
- More complicated IVF cycles
- For those who do conceive, greater complications of pregnancy exist including :
- Higher frequency of miscarriage
- Greater anesthesia and surgical complications if any surgery required (e.g. D&C for miscarriage)
- Greater frequency of hypertension, gestational diabetes, pre-eclampsia, stillbirth and other complication of pregnancy.
- Increased risks of requiring caesarean section delivery. The caesarean section rate is almost 50% in obese women & the postoperative complications following C Section
- Due to larger babies, there is a greater delivery complication rate for those delivering vaginally.
- Epigenetic changes in response to increased fetal exposure to glucose, lipids, and inflammatory cytokines may result in permanent or transient changes in metabolic programming, leading to adverse health outcomes in adult life
Importantly, with all these potential complications & adverse effects, reduction in BMI (person's weight in kilograms divided by his or her height in meters squared) through weight loss has been demonstrated to significantly improve fertility therapy success, lower complications of therapy & lower complications of pregnancy