McAnarney E R, Bayer C A, Kogut C F, Silverman M G, Iker H P
J Adolesc Health Care. 1986 Mar;7(2):96-100. doi: 10.1016/s0197-0070(86)80003-1.
Seventy-nine percent of a group of adolescent mothers reported coitus during pregnancy. There was a significant difference between the mean birthweight and gestational age of infants born to mothers who reported coitus within 90 days of delivery compared to the mean birthweight and gestational age of infants of mothers who reported no gestational age of infants of mothers who reported no coitus within 90 days of delivery. Thirty-nine percent of the variance in birthweight was explained by maternal factors alone, but only 1.0% of the variance in birthweight was accounted for by the interval between last coitus and delivery. Prepregnancy weight (r = 0.380) and weight gain during pregnancy (r = 0.327) contributed 19.1% and 7.4% of the variance in birthweight, respectively.
一组青少年母亲中有79%报告在孕期有过性交。与在分娩前90天内无性交的母亲所生婴儿的平均出生体重和胎龄相比，报告在分娩前90天内有性交的母亲所生婴儿的平均出生体重和胎龄存在显著差异。出生体重差异的39%仅由母亲因素解释，但出生体重差异中只有1.0%可由最后一次性交与分娩之间的间隔来解释。孕前体重（r = 0.380）和孕期体重增加（r = 0.327）分别占出生体重差异的19.1%和7.4%。
