Cnattingius S, Bergström R, Lipworth L, Kramer M S
Department of Medical Epidemiology, Karolinska Institute, Stockholm, Sweden.
N Engl J Med. 1998 Jan 15;338(3):147-52. doi: 10.1056/NEJM199801153380302.
Obesity before pregnancy is associated with an increased risk of several adverse outcomes of pregnancy. The risk profiles among lean, normal, or mildly overweight women are not, however, well established.
We studied the associations between prepregnancy body-mass index (defined as the weight in kilograms divided by the square of the height in meters) and the frequency of late fetal death, early neonatal death, preterm delivery, and delivery of a small-for-gestational-age infant in a population-based cohort of 167,750 women in Sweden in 1992 and 1993. The women were categorized as follows, according to body-mass index: lean, less than 20.0; normal, 20.0 through 24.9; overweight, 25.0 through 29.9; and obese, 30.0 or more. The estimates were adjusted for maternal age, parity, smoking, education, whether the mother was living with the father, and maternal height.
Among nulliparous women, the odds ratios for late fetal death were increased among women with higher body-mass-index values as compared with lean women, as follows: normal women, 2.2 (95 percent confidence interval, 1.2 to 4.1); overweight women, 3.2 (95 percent confidence interval, 1.6 to 6.2); and obese women, 4.3 (95 percent confidence interval, 2.0 to 9.3). Among parous women, only obese women had a significant increase in the risk of late fetal death (odds ratio, 2.0; 95 percent confidence interval, 1.2 to 3.3). Among nulliparous women, the risk of very preterm delivery (at < or =32 weeks' gestation) was significantly increased among obese as compared with lean women (odds ratio, 1.6; 95 percent confidence interval, 1.1 to 2.3), whereas among parous women, the risk was highest among those who were lean. The risk of delivering a small-for-gestational-age infant decreased more with increasing body-mass index among parous than among nulliparous women.
Higher maternal weight before pregnancy increases the risk of late fetal death, although it protects against the delivery of a small-for-gestational-age infant.
孕前肥胖与多种不良妊娠结局风险增加相关。然而，体重正常或轻度超重女性的风险状况尚未明确。
我们在1992年和1993年对瑞典167,750名女性的人群队列进行研究，探讨孕前体重指数（定义为体重千克数除以身高米数的平方）与死胎、早期新生儿死亡、早产以及小于胎龄儿出生频率之间的关联。根据体重指数将这些女性分类如下：体重过轻，小于20.0；正常，20.0至24.9；超重，25.0至29.9；肥胖，30.0及以上。对估计值进行了产妇年龄、产次、吸烟情况、教育程度、母亲是否与父亲同住以及产妇身高的校正。
在未生育女性中，与体重过轻的女性相比，体重指数较高的女性死胎的比值比升高，情况如下：正常体重女性，2.2（95%置信区间，1.2至4.1）；超重女性，3.2（95%置信区间，1.6至6.2）；肥胖女性，4.3（95%置信区间，2.0至9.3）。在已生育女性中，只有肥胖女性死胎风险显著增加（比值比，2.0；95%置信区间，1.2至3.3）。在未生育女性中，肥胖女性与体重过轻的女性相比，极早产（孕周≤32周）风险显著增加（比值比，1.6；95%置信区间，1.1至2.3），而在已生育女性中，体重过轻的女性风险最高。已生育女性中，随着体重指数增加，小于胎龄儿出生风险的降低幅度大于未生育女性。
孕前母亲体重增加会增加死胎风险，尽管可降低小于胎龄儿出生风险。
