How does BMI influence fertility and ART outcomes?

• A. Obesity and underweight status can disrupt ovulation, reduce response to stimulation, increase miscarriage risk, and lower live birth rates in ART.
• B. BMI has no impact on fertility.
• C. Only obesity affects fertility; underweight has no effect.
• D. Higher BMI improves response to stimulation.

Answer: (C)

BMI extremes influence fertility and ART outcomes because energy balance and hormonal regulation tightly control ovulation and how the ovaries respond to stimulation. Obesity disrupts ovulatory function through insulin resistance and higher androgens, can blunt ovarian response to gonadotropin, and may impair endometrial receptivity, all of which raise miscarriage risk and lower live birth rates in ART. Underweight also affects fertility by suppressing the hypothalamic-pituitary-ovarian axis due to insufficient energy reserves, leading to irregular or absent ovulation and poorer follicular development and endometrial conditions, reducing ART success. In short, both ends of the BMI spectrum can harm fertility and ART outcomes, affecting ovulation, stimulation response, implantation, and pregnancy viability.