SAN ANTONIO — Routine repeat screening for sexually transmitted infections is worthwhile for pregnant adolescents during the third trimester, a Canadian study showed.
“We screen all adolescent pregnancies at baseline and again during the third trimester. This is different from adults, who we only screen at baseline,” said Dr. Anjali Aggarwal of the Hospital for Sick Children in Toronto.
Part of the concern is that teenage women tend to use condoms less often once they become pregnant (Am. J. Public Health 2009 April 16 [doi:10.2105/AJPH.2007.131870
She and her associates at the University of Toronto hospital assessed 89 pregnant adolescents with a median age of 16 years (range, 13-17 years) who were screened both at baseline and during the third trimester. They also screened 77 of the same participants again during the postpartum period.
Overall, 26 patients (29%) were diagnosed with an STI during or after pregnancy. “I was surprised it was that high,” Dr. Aggarwal said in an interview. Specifically, STIs were detected in 17 patients during the first trimester, 7 in the third trimester, and 1 in the postpartum period. An additional patient was diagnosed in the first trimester, treated, and then treated again during the third trimester, based on symptoms later in her pregnancy.
The finding that more than 25% of the patients identified as having an STI were diagnosed in the third trimester justifies routine rescreening, said Dr. Aggarwal.
Only one statistically significant risk factor was associated with an STI in pregnancy: a history of not using contraception, other than a condom. There was no significant association with patient age, previous pregnancy, or previous STI. Women who lived with a partner, lived with the baby's father, or reported only one previous sexual partner versus more than one were at lower risk of an STI during pregnancy. These factors only trended toward statistical significance.
Dr. Aggarwal said she plans to compare computer-based patient interviews with those done by clinicians. The goal would be to determine if pregnant teenagers are more forthright when interfacing with a computer, she said.