Obesity and poor reproductive outcome: the potential role of the endometrium
Authors: José Bellver, Marco Melo, Ernesto Bosch, Vicente Serra, José Remohí, Antonio Pellicer
(Fertility and Sterility 2007; 88: 446-451)
OBJECTIVE: We have performed this study to analyze the potential role of extra-ovarian factors, like endometrium, in the reproductive outcome of obese patients.
DESIGN: Retrospective study.
SETTING: Instituto Universitario IVI, Valencia, Spain.
PATIENTS: All first cycles (n= 2656) of OD taking place in an University- affiliated infertility clinic between January, 2001 and July, 2005, in which good quality embryos were replaced, were included and divided into groups according to their BMI: <20 kg/m2 (n= 471); 20-24.9 kg/m2 (n= 1613); 25-29.9 kg/m2 (n= 450); ≥ 30 kg/m2 (n=122). INTERVENTION: The oocyte donors were submitted to controlled ovarian hyperstimulation. Recipients received an well established hormonal replacement therapy for endometrial preparation. IVF or ICSI were performed according to semen characteristics.
MAIN OUTCOME MEASURE: Recipient BMI groups were compared regarding IVF outcome.
RESULTS: Implantation, pregnancy, miscarriage and ongoing pregnancy rates were similar among BMI groups, though there was a negative trend when BMI increased. Ongoing pregnancy rates per cycle were poorer in the overweight and obese groups than in the underweight and normal groups (p = 0.017). In addition, women under 25 kg/m2 presented an ongoing pregnancy rate per cycle rate of 38.3% compared to 45.5% in those with ≥ 25 kg/m2 (p= 0.002).
CONCLUSION: Weight excess exerts a subtle detrimental extra-ovarian effect on reproduction.
KEYWORDS: Assisted reproduction, endometrium, implantation, miscarriage, obesity, ovum donation, pregnancy.