When obese adolescent women did use contraceptives such as the oral contraceptive pill, they were less consistent in using them than peers with normal weights.
Researchers at the University of Michigan in Ann Arbor, MI, assessed the sexual practices and contraceptive use of 900 women aged 18-19 in a longitudinal study. Their findings indicate that obese adolescent women could be at an increased risk of unintended pregnancy.
"Reducing adolescent pregnancy is a national public health priority and we need to understand which adolescents are at higher risk of pregnancy," says lead author Dr. Tammy Chang, an assistant professor of family medicine.
"Our findings suggest that obesity may be an important factor associated with adolescent women's sexual behavior."
According to the Centers for Disease Control and Prevention (CDC), rates of teenage pregnancy have fallen in recent years. In 2013, 273,105 babies were reported to have been born to women aged 15-19 years, a 10% drop from 2012. Despite this decrease, however, the teen pregnancy rate in the US is significantly higher than in many other western industrialized nations.
There are numerous health consequences associated with adolescent pregnancy, which include miscarriage and stillbirth alongside indirect outcomes such as living in poverty and relying on public assistance. Similarly, obese pregnant women are at an increased risk for many other conditions, such as gestational diabetes, hypertension, blood clots, birth-related injuries and requiring delivery by Cesarean section.
"Understanding sexual behaviors by weight status among adolescents is critical because of the risk of dangerous outcomes for moms and babies associated with obesity," explains Dr. Chang. Research is particularly warranted among 18-19-year olds, who are at the greatest risk of pregnancy among adolescents.
Obese adolescents 'less protected from unintended pregnancy'
For the study - published in The Journal of Pediatrics - the researchers analyzed a total of 26,545 weekly journal surveys for 900 women aged 18-19 obtained over the course of a year. The surveys measured sexual practices including use of contraceptives, number of sexual partners and average length of relationships for participants.
Each participant was also assessed by research staff in a face-to-face interview at the start of the study where their weight was measured.
The researchers found no differences in the number of partners, length of relationships and frequency of sex reported by obese women and their normal weight peers. However, obese participants were less likely to use contraception during weeks involving sex (84% of weeks) than those with normal weight (91% of weeks).
In addition, when contraception was used, obese women only reported using it consistently for 68% of these weeks, compared with normal weight women who used contraception consistently for 78%.
"Consequently, sexually active obese adolescents in our sample were less protected from unintended pregnancy, compared with normal weight adolescents," the authors conclude.
They suggest that lower levels of contraceptive use may be attributable to socioeconomic barriers and limited health literacy that could be behind the development of obesity. Low self-esteem could also make obese adolescents feel uncomfortable acquiring contraceptives from clinicians or over-the-counter.
It is important that researchers investigate why specific groups at greater risk of obesity and adolescent pregnancy, as the two health statuses can contribute to a cycle of poor health among mothers and their children.
"By understanding the barriers that put certain groups of teens at higher risk of unintended pregnancies, clinicians and researchers can tailor interventions to empower adolescents to make healthier sexual choices," concludes Dr. Chang.