Selection bias in determining the age dependence of waiting time to pregnancy
Selection bias in determining the age dependence of waiting time to pregnancy
复制标题
DOI：
10.1093/aje/152.6.565
复制
发表时间：
2000-09-15
影响因子：
5
通讯作者：
Grandjean, P
中科院分区：
文献类型：
--
作者：
Jensen, TK;Scheike, T;Grandjean, P
许多研究发现，随着女性年龄的增长，生育能力下降，即在月经周期中怀孕的能力。为了评价孕妇年龄对等待怀孕时间的影响，作者回顾了1972-1987年在丹麦欧登塞大学医院接受预防性产前保健的所有孕妇的病历，其中只包括每个妇女的首次怀孕和计划怀孕（n = 14，754），生育率比值比（FR）计算为年龄较大的女性在月经周期中受孕的几率除以15-24岁女性的几率。校正混杂因素后，25-29岁女性的FR为1.12（95%置信区间（CI）：1.04，1.20），30-34岁女性为1.15（95% CI：1.01，1.30），34岁以上女性的FR为2.44（95% CI：1.84，3.22）。随着年龄的增加，受孕能力与以前的研究相反，可能是由于选择偏差，因为不孕妇女不包括在内。此外，一些在有效的避孕方法可用之前意外怀孕的非常有生育能力的年轻女性，因此被排除在妊娠研究之外，现在可以使用口服避孕药，直到她们计划在以后的生活中怀孕并被纳入。
Many studies have found decreased fecundability, that is, the ability to conceive in a menstrual cycle, with increasing female age. To evaluate the effect of maternal age on waiting time to pregnancy, the authors reviewed hospital charts of all pregnant women attending prophylactic antenatal care at Odense University Hospital, Denmark, during 1972-1987, Only the first pregnancy of each woman and only planned pregnancies were included (n = 14,754), The fecundability odds ratio (FR) was calculated as the odds of a conception in a menstrual cycle among the older women divided by the odds among women aged 15-24 years. The FR for women aged 25-29 years was 1.12 (95% confidence interval (CI): 1.04, 1.20), for women aged 30-34 years it was 1.15 (95% CI: 1.01, 1.30), and for women above 34 years the FR was 2.44 (95% CI: 1.84, 3.22) after adjustment for confounders. The increased fecundability with age is contrary to previous studies and may be explained by selection bias, as sterile women were not included. In addition, some very fertile young women who became pregnant by accident before efficient birth control methods were available and therefore were excluded from time to pregnancy studies may now use oral contraceptives until they plan a pregnancy later in life and are included.