Last week, the journal JAMA Network Open published a study that found that Canadian teenagers who became pregnant were more likely to die before reaching their 31st birthday. The researchers obtained comprehensive data from Ontario’s health registry. They were able to analyze data from over 2 million Canadian females alive at twelve years of age between 1991 and 2021. This study has been covered by a number of media outlets including the New York Times, Spectrum News, and Yahoo! Canada.
For the most part, the study is analytically rigorous and well done. The researchers are able to hold constant a range of demographic and economic factors. The study provides compelling statistical evidence that pregnancy increased the risk of premature death among Canadian teens. Overall, the risk of premature death was 1.5 times higher among those with one teen pregnancy and over two times higher for those with multiple teen pregnancies. It also found that the risk of premature death was higher among younger Canadian teenagers who became pregnant.
Interestingly, the study purportedly finds that pregnant Canadian teens who obtained abortions had lower mortality rates than pregnant Canadian teens who carried pregnancies to term. However, I would recommend interpreting this finding with caution. This is for several reasons.
First, teens who obtained abortions were still 40 percent more likely to die prematurely than teens who never became pregnant in the first place. Second, the study lumps together Canadian teens who had ectopic pregnancies, miscarriages, and stillbirths with those who carried pregnancies to term. This potentially biases the results. Third, while the researchers held constant some socioeconomic variables, they did not consider the future income or socioeconomic status of pregnant Canadian teens. Pregnant teenagers who were professionally ambitious or planned on attending college might have been more likely to obtain abortions. Their potentially future higher incomes might explain their lower premature-death rates.
For over 40 years, U.S. policy-makers have prioritized lowering teen-pregnancy rates. These efforts have been successful. Since 1990, the teen pregnancy rate has fallen by over 73 percent in the United States. While many in the mainstream media are quick to credit contraception use, data from both the National Survey of Family Growth and the Youth Risk Behavior Survey show durable, long-term declines in the percentage of teenagers who are sexually active. This new research from Canada nicely shows that policy efforts to reduce teen-pregnancy rates have had important long-term health benefits.