The relationship between unplanned pregnancy and maternal body mass index 2009-2012.

ObjectiveTo analyse the relationship between unplanned pregnancy and maternal Body Mass Index (BMI). MethodsA prospective case-control study of planned vs. unplanned pregnancies among women who delivered an infant weighing ≥ 500 g during the four years 2009–2012 in a large maternity hospital in Ireland. Maternal weight and height were measured at the first antenatal visit before calculation of BMI. Clinical and sociodemographic details were computerised. BMI was categorised according to the World Health Organization. The epidemiological associations were examined using logistic regression, adjusted for confounding variables. ResultsBetween 2009 and 2012, 34,377 women were included, 31.7% (n= 10,894) reported an unplanned pregnancy and 16.6% (n= 5647) were obese. The odds ratios of unplanned pregnancy were greater among obese women compared with those of normal BMI (unadjusted Odds Ratio (OR) 1.3; 95% Confidence Interval (CI) 1.3–1.4p< 0.001). These ratios increased with increasing BMI (mild unadjusted OR 1.3; CI 1.2–1.4p< 0.001; moderate unadjusted OR 1.4; CI 1.2–1.6p< 0.001; severe obesity unadjusted OR 1.7; CI 1.4–2.0p< 0.001). The higher rate of unplanned pregnancy among obese women was associated with a lower rate of contraception usage and a higher rate of contraceptive failure. Only 37.6% (n= 2112) of obese women took preconceptional folic acid to prevent neural tube defects compared with 46.1% (n= 8176) of women with a normal BMI (p< 0.001). ConclusionHigher rates of unplanned pregnancy among obese women compared with women with a normal BMI is associated with compromised prepregnancy care in this high-risk population. Chinese Abstract 摘要： 目的分析意外怀孕和孕妇体重指数(BMI)之间的关系。 方法对在爱尔兰的一个大型妇产科医院里，从2009 - 2012年四年间，生产婴儿的体重≥500 g的计划内和计划外怀孕的女性，进行前瞻性病例对照研究。在计算体重指数之前的第一次产前随访时，测量孕妇的体重和身高。临床和社会人口的详细资料已用电脑处理。体重指数是根据世界卫生组织进行的分类。使用逻辑回归进行了流行病学关联调查，同时调整混杂变量。 结果从2009年至2012年期间， 34377名女性被纳入研究。据报道， 31.7%(n=10894)的意外怀孕女性中有16.6%(n=5647)为肥胖女性。肥胖女性意外怀孕的比值比比体重指数(BMI)正常的女性意外怀孕的比值比大(未调整的比值比为1.3；95%可信区间：1.3-1.4， p < 0.001)。这些比值随着体重指数的增加而增大(轻微调整的比值比为1.3；可信区间：1.2-1.2， p < 0.001；适度调整的比值比为1.4；可信区间；1.2-1.6 ，p < 0.001；严重肥胖未经调整的比值比为1.7；可信区间；1.4-2.0 ，p < 1.4)。肥胖女性中较高的意外怀孕率与较低的避孕率及较高的避孕失败率有关。与46.1%(n=8176)的体重指数正常的女性相比，只有37.6%(n=2112) 的肥胖女性服用叶酸来预防神经管缺陷(p < 0.001)。 结论肥胖女性意外怀孕的几率比体重指数正常的女性高，这个结论与肥胖女性放弃孕前保健有关。 关键词： 肥胖孕妇；意外怀孕；避孕 [ABSTRACT FROM PUBLISHER]