Female obesity impairs in vitro fertilization outcome without affecting embryo quality.
OBJECTIVE
To compare embryo quality and reproductive outcome in our IVF program according to the women's body mass index (BMI).


METHODS
Retrospective study.


METHODS
University-affiliated infertility clinic, between January 2001 and April 2007.


METHODS
Women undergoing a total of 6,500 IVF-intracytoplasmic sperm injection (ICSI) cycles.


METHODS
Six thousand five hundred IVF-ICSI cycles were included and divided into four groups: lean (<20 kg/m(2); n = 1,070; 16.5%); normal (20-24.9 kg/m(2); n = 3,930; 60.5%); overweight (25-29.9 kg/m(2); n = 1,081; 16.6%); and obese (> or =30 kg/m(2); n = 419; 6.4%).


METHODS
Comparison of embryo quality and reproductive outcome (implantation, pregnancy, miscarriage, and live birth rates) among BMI groups.


RESULTS
No difference in insemination procedure, fertilization rate, day of ET, mean number of transferred and cryopreserved embryos, percentage of blastocyst transfers, or embryo quality on day 2 and 3 was found among groups. However, implantation, pregnancy, and live birth rates were poorer in obese women. In fact, pregnancy and live birth rates were reduced progressively with each unit of BMI (kilograms per square meter) with a significant odds ratio of 0.984 (95% confidence interval 0.972-0.997) and 0.981 (95% confidence interval 0.967-0.995), respectively. In addition, the cumulative pregnancy rate after four IVF cycles was reduced as BMI increased.


CONCLUSIONS
Female obesity impairs IVF outcome, but embryo quality is not affected, pointing to an alteration in the uterine environment.
Bellver
José
J
Instituto Valenciano de Infertilidad, University of Valencia, Plaza de la Policía Local, 3, 46015 Valencia, Spain. jbellver@ivi.es
Ayllón
Yanira
Y
Ferrando
Marcos
M
Melo
Marco
M
Goyri
Eduardo
E
Pellicer
Antonio
A
Remohí
José
J
Meseguer
Marcos
M
D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D005306:Fertilization / Q000502:physiology; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D008297:Male; D008677:Metaphase; D009765:Obesity / Q000503:physiopathology*; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D050177:Overweight / Q000503:physiopathology; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods; D013851:Thinness / Q000503:physiopathology; D016896:Treatment Outcome