Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.
Hum Reprod. 2010 Jan;25(1):253-64. doi: 10.1093/humrep/dep360. Epub 2009 Oct 14.
Recent studies have shown that both female and male obesity may delay time-to-pregnancy (TTP). Little is known about central adiposity or weight gain and fecundability in women.
We examined the association between anthropometric factors and TTP among 1651 Danish women participating in an internet-based prospective cohort study of pregnancy planners (2007-2008). We categorized body mass index (BMI = kg/m(2)) as underweight (<20), normal weight (20-24), overweight (25-29), obese (30-34) and very obese (> or =35). We used discrete-time Cox regression to estimate fecundability ratios (FRs) and 95% confidence intervals (CI), controlling for potential confounders.
We found longer TTPs for overweight (FR = 0.83, 95% CI = 0.70-1.00), obese (FR = 0.75, 95% CI = 0.58-0.97), and very obese (FR = 0.61, 95% CI = 0.42-0.88) women, compared with normal weight women. After further control for waist circumference, FRs for overweight, obese, and very obese women were 0.72 (95% CI = 0.58-0.90), 0.60 (95% CI = 0.42-0.85) and 0.48 (95% CI = 0.31-0.74), respectively. Underweight was associated with reduced fecundability among nulliparous women (FR = 0.82, 95% CI = 0.63-1.06) and increased fecundability among parous women (FR = 1.61, 95% CI = 1.08-2.39). Male BMI was not materially associated with TTP after control for female BMI. Compared with women who maintained a stable weight since age 17 (-5 to 4 kg), women who gained > or =15 kg had longer TTPs (FR = 0.72, 95% CI = 0.59-0.88) after adjustment for BMI at age 17. Associations of waist circumference and waist-to-hip ratio with TTP depended on adjustment for female BMI: null associations were observed before adjustment for BMI and weakly positive associations were observed after adjustment for BMI.
Our results confirm previous studies showing reduced fertility in overweight and obese women. The association between underweight and fecundability varied by parity.
最近的研究表明，女性和男性肥胖都可能延迟怀孕时间（TTP）。关于中心性肥胖或体重增加与女性生育能力的关系知之甚少。
我们研究了丹麦 1651 名参与在线妊娠计划前瞻性队列研究的女性（2007-2008 年）中，人体测量因素与 TTP 之间的关系。我们将体重指数（BMI=kg/m²）分为体重不足（<20）、正常体重（20-24）、超重（25-29）、肥胖（30-34）和非常肥胖（≥35）。我们使用离散时间 Cox 回归来估计生育能力比值（FR）和 95%置信区间（CI），并控制潜在的混杂因素。
与正常体重女性相比，超重（FR=0.83，95%CI=0.70-1.00）、肥胖（FR=0.75，95%CI=0.58-0.97）和非常肥胖（FR=0.61，95%CI=0.42-0.88）的女性 TTP 较长。进一步控制腰围后，超重、肥胖和非常肥胖女性的 FR 分别为 0.72（95%CI=0.58-0.90）、0.60（95%CI=0.42-0.85）和 0.48（95%CI=0.31-0.74）。体重不足与初产妇生育能力降低相关（FR=0.82，95%CI=0.63-1.06），与经产妇生育能力增加相关（FR=1.61，95%CI=1.08-2.39）。控制女性 BMI 后，男性 BMI 与 TTP 无明显相关性。与 17 岁以来体重稳定（-5 至 4kg）的女性相比，体重增加≥15kg 的女性 TTP 较长（FR=0.72，95%CI=0.59-0.88），并在调整 17 岁时 BMI 后。腰围和腰臀比与 TTP 的关系取决于对女性 BMI 的调整：在调整 BMI 之前，关联呈零关联，在调整 BMI 之后，关联呈弱阳性。
我们的结果证实了之前的研究，即超重和肥胖女性的生育能力降低。与生育能力的关系因初产状态而异。
