Impact of Obesity on Intracytoplasmic Sperm Injection Cycle Outcome: a Prospective Cohort Study

Obesity has been associated with menstrual irregularities, chronic an-ovulation, infertility, and poor outcomes in women undergoing in vitro fertilization.

There is strong evidence that obesity is associated with a higher n vitro fertilization cycle cancellation rate (despite administration of higher doses of exogenous gonadotrophins), a lower mature oocyte yield and lower number of cryopreservation cycles.

Furthermore, obese women have been shown to have impaired response to ovarian stimulation and significantly lower live births after in vitro fertilization. Indeed, obesity affects many ovarian intra-follicular steroidogenic, metabolic and inflammatory pathways.This is particularly evident in women with abdominal (central obesity). Waist circumference measurement is used to identify individuals with abdominal obesity but it cannot differentiate between intra-abdominal fat and subcutaneous abdominal fat accumulation.

The reliable measurement of visceral fat and subcutaneous fat is not only important as a tool to predict cardiovascular and metabolic disease risk, but it is also essential to evaluate the effect of these fat compartments on female reproductive function. Intra-abdominal fat accumulation is related to insulin resistance in women with polycystic ovary syndrome and in these women the resulting hyperinsulinemia contributes to an-ovulation.

Obese anovulatory women with polycystic ovary syndrome who resume ovulation during a 6-month lifestyle program lose more visceral fat with no difference in the change of subcutaneous fat compared to the women who did not resume ovulation.

Another recent study that enrolled 140 non-polycystic ovary syndrome in vitro fertilization women demonstrated that women with increased waist circumference and higher follicular fluid leptin have less oocytes fertilized and failed in vitro fertilization outcomes. Increased intra-abdominal fat during early pregnancy is associated with insulin resistance and increased diastolic blood pressure and it can predict glucose intolerance in later pregnancy.