Eskild Anne, Vatten Lars J, Nesheim Britt-Ingjerd, Vangen Siri
Department of Obstetrics and Gynaecology, Akershus University Hospital and Medical Faculty, University of Oslo, Lørenskog, Norway.
Acta Obstet Gynecol Scand. 2009;88(5):569-74. doi: 10.1080/00016340902814567.
We wanted to study to what extent induced abortion rates influence the age-dependent estimates of miscarriage risk.
Register-based study.
Linkage between hospital records and the Norwegian Population Registry.
Included were all women 15-49 years of age in Oslo, Norway, who were pregnant during the three-year study period, 27,932 women.
We estimated proportions with miscarriage according to maternal age with and without inclusion of women with induced abortion in the denominator.
Proportions with miscarriage in each age group and odds ratios of miscarriage, with age group 25-29 years as the reference.
When only women with pregnancies intended to term were included in the denominator, 9.4% of the women were estimated to have miscarriage as the only reproductive event during the three-year period and 6.8% had both miscarriage and delivery. The corresponding figures when also women with induced abortions were included in the denominator, were 7.0 and 5.0%. When taking induced abortion into account, the reduction in estimated proportion with miscarriage during the study period was greatest in the age groups with the highest induced abortion rates, women 15-19 years old (from 22.8 to 6.4%) and women 45-49 years old (from 57.9 to 41.0%).
Estimates of age-dependent risk of miscarriage may be strongly influenced by induced abortion rates.
我们想研究人工流产率在多大程度上影响与年龄相关的流产风险估计。
基于登记处的研究。
医院记录与挪威人口登记处之间的关联。
纳入了挪威奥斯陆所有年龄在15至49岁之间、在三年研究期间怀孕的女性，共27932名女性。
我们根据产妇年龄估计流产比例，分母中分别纳入和不纳入人工流产女性。
各年龄组的流产比例以及流产的比值比，以25至29岁年龄组作为参照。
当分母中仅纳入计划足月分娩的女性时，估计9.4%的女性在三年期间仅有流产这一妊娠结局，6.8%的女性既有流产又有分娩。当分母中也纳入人工流产女性时，相应数字分别为7.0%和5.0%。考虑人工流产因素后，研究期间流产估计比例下降幅度最大的是人工流产率最高的年龄组，即15至19岁女性（从22.8%降至6.4%）和45至49岁女性（从57.9%降至41.0%）。
与年龄相关的流产风险估计可能会受到人工流产率的强烈影响。
