Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon, USA
National Institute of Public Health (INSP), Center for Health Systems Research (CISS), Cuernavaca, Morelos, Mexico.
BMJ Sex Reprod Health. 2021 Jul;47(3):e9. doi: 10.1136/bmjsrh-2020-200795. Epub 2021 Jan 15.
We examined parity and age among women seeking an abortion in Mexico City's public first-trimester abortion programme, Interrupcion Legal de Embarazo (ILE). We hypothesised that younger women, especially students, used abortion to prevent first births while older women used abortion to limit births.
We used clinical data from a sample of 47 462 women who had an abortion between 2007 and 2016 and classified them as nulliparous or parous according to previous births prior to the abortion. We used logistic regression to identify sociodemographic and clinical factors associated with using abortion to prevent a first birth (nulliparous) versus limiting births (parous) and calculated absolute multivariable predicted probabilities.
Overall, 41% of abortions were in nulliparous women seeking to prevent a first birth, and 59% were in women who already had one or more children. The adjusted probability of using abortion to prevent a first birth was 80.4% (95% CI 78.3 to 82.4) for women aged 12-17 years and 54.3% (95% CI 51.6 to 57.0) for women aged 18-24 years. Adolescents (aged 12-17 years) who were employed or students had nearly 90% adjusted probability of using abortion to prevent a first birth (employed 87.8%, 95% CI 82.9 to 92.8; students 88.5%, 95% CI 82.9 to 94.1). At all ages, employed women and students had higher probabilities of using abortion to prevent a first birth compared with unemployed women and women who work in the home.
Legal first-trimester abortion services in Mexico can help prevent first births in adolescents, especially students.
我们研究了在墨西哥城公共早孕堕胎项目（ILE）中寻求堕胎的女性的生育次数和年龄。我们假设年轻女性，尤其是学生，会使用堕胎来避免首次生育，而年长女性则会使用堕胎来限制生育。
我们使用了 2007 年至 2016 年间 47462 名接受堕胎的女性的临床数据，根据堕胎前的生育情况将其分为初产妇和经产妇。我们使用逻辑回归来确定与使用堕胎来避免首次生育（初产妇）与限制生育（经产妇）相关的社会人口学和临床因素，并计算了绝对多变量预测概率。
总体而言，41%的堕胎是初产妇为避免首次生育而进行的，59%是已有一个或多个孩子的女性进行的。调整后的使用堕胎来避免首次生育的概率为 12-17 岁的女性 80.4%（95%可信区间 78.3 至 82.4），18-24 岁的女性 54.3%（95%可信区间 51.6 至 57.0）。就业或学生身份的青少年（12-17 岁）使用堕胎来避免首次生育的调整后概率接近 90%（就业 87.8%，95%可信区间 82.9 至 92.8；学生 88.5%，95%可信区间 82.9 至 94.1）。在所有年龄段，就业女性和学生比失业女性和从事家庭工作的女性更有可能使用堕胎来避免首次生育。
墨西哥的合法早孕堕胎服务可以帮助避免青少年，尤其是学生的首次生育。
