Subfecundity in overweight and obese couples.
BACKGROUND
Recent studies indicate that not only women's but also men's obesity has adverse effects on fecundity and since fecundity is a couple concept, we examined fecundity in relation to overweight and obesity of the couple. We also examined the association between weight changes and fecundity over time.


METHODS
Between 1996 and 2002, 64 167 pregnant women enrolled in the Danish National Birth Cohort were interviewed during and 18 months after pregnancy. Information on body mass index (BMI) and waiting time to pregnancy (TTP) was available for 47 835 couples.


RESULTS
Among men and women with a BMI of 18.5 kg/m(2) or more, we found a dose-response relationship between increasing BMI group and subfecundity (a TTP of more than 12 months): Odds ratio (OR) = 1.32 (95% CI: 1.26-1.37) for women and OR = 1.19 (95% CI: 1.14-1.24) for men. Among 2374 women with an initial BMI of 18.5 kg/m(2) or more, who participated more than once in the Danish National Birth Cohort, each kilogram increment in weight between the two pregnancies was associated with a 2.84 (95% CI: 1.33-4.35) days longer TTP.


CONCLUSIONS
Couples have a high risk of being subfecund if they are both obese.
Ramlau-Hansen
C H
CH
Department of Epidemiology, UCLA School of Public Health, University of California-Los Angeles, 650 Charles E. Young Drive S., Los Angeles, CA 90095, USA. craha@as.aaa.dk
Thulstrup
A M
AM
Nohr
E A
EA
Bonde
J P
JP
Sørensen
T I A
TI
Olsen
J
J
D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005298:Fertility; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight; D011247:Pregnancy