Obesity affects spontaneous pregnancy chances in subfertile, ovulatory women.
BACKGROUND
Obesity is increasing rapidly among women all over the world. Obesity is a known risk factor for subfertility due to anovulation, but it is unknown whether obesity also affects spontaneous pregnancy chances in subfertile, ovulatory women.


METHODS
We evaluated whether obesity affected the chance of a spontaneous pregnancy in a prospectively assembled cohort of 3029 consecutive subfertile couples. Women had to be ovulatory and had to have at least one patent tube, whereas men had to have a normal semen analysis. Time to spontaneous ongoing pregnancy within 12 months was the primary endpoint.


RESULTS
The probability of a spontaneous pregnancy declined linearly with a body mass index (BMI) over 29 kg/m(2). Corrected for possible related factors, women with a high BMI had a 4% lower pregnancy rate per kg/m(2) increase [hazard ratio: 0.96 (95% CI 0.91-0.99)].


CONCLUSIONS
These results indicate that obesity is associated with lower pregnancy rates in subfertile ovulatory women.
van der Steeg
Jan Willem
JW
Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, The Netherlands. j.w.vandersteeg@amc.uva.nl
Steures
Pieternel
P
Eijkemans
Marinus J C
MJ
Habbema
J Dik F
JD
Hompes
Peter G A
PG
Burggraaff
Jan M
JM
Oosterhuis
G Jur E
GJ
Bossuyt
Patrick M M
PM
van der Veen
Fulco
F
Mol
Ben W J
BW
D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007247:Infertility, Female / Q000150:complications* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000473:pathology; D010060:Ovulation; D011247:Pregnancy; D018873:Pregnancy Rate; D011336:Probability; D011446:Prospective Studies