study published Monday in the journal JAMA Network Open.
number of preterm births slightly rose from 2016 to 2019, so more work to identify risk factors has been needed.
from 2013 to 2018, according to the US Centers for Disease Control and Prevention. Maternal STIs have been known to harm developing fetuses, but previous studies on this link have been inconclusive, the researchers wrote — so the authors used nationwide birth certificate data and medical records of more than 14 million mother-infant pairs to examine the links between preterm birth and mothers’ infections.
Of all US mothers who had given birth between January 2016 and December 2019, 1.9% (267,260) had chlamydia, 0.3% had gonorrhea and 0.1% were infected with syphilis before or during their pregnancies. Among all newborns, 8% (1,146,800) were born prematurely. Mothers with chlamydia, gonorrhea or syphilis were 1.04, 1.10 and 1.17 times more likely to have a moderately preterm birth — meaning between 32 and 36 weeks of gestation — than women without STIs, respectively, the authors found.
Infections with gonorrhea and syphilis were more strongly associated with very preterm births, which meant between 28 and 31 weeks.
“Even though some of the effects are small, STIs do appear to increase your chance of delivering preterm,” said Kelli Ryckman, a coauthor of the study and a professor of epidemiology at the University of Iowa’s College of Public Health.
How STIs could affect birth time
gonorrhea are common sexually transmitted infections that can affect people of all genders who have vaginal, anal or oral sex with someone who is infected, according to the CDC. Chlamydia can cause serious, permanent damage to a woman’s reproductive system. And both STIs can cause preterm birth and be transferred to babies during childbirth, possibly causing pneumonia and ear infections.
chorioamnionitis, a condition wherein bacteria infects the membranes surrounding the fetus and the fluid in which the fetus floats.
“All of these responses may cause inflammation and activate the maternal and/or fetal immune system, which is an established cause of preterm birth,” the researchers suggested. “However, whether a maternal infection induces preterm birth may also depend on the characteristic and concentration of the pathogen and the timing of infection.”
a commentary on the study. The doctors, who are affiliated with the obstetrics and gynecology department at the University of Texas Southwestern Medical Center, Dallas, weren’t involved in the study.
Observational studies such as this one can’t take into account individual behaviors and other factors potentially responsible for preterm birth, including chronic stress, gestational age of diagnosis or lack of access to treatment, Adhikari and Roberts wrote.
“Without a better understanding of which infections were and were not treated, we have little to guide a search for targeted interventions to prevent preterm birth in a cohort with treatable infectious diseases,” they added.
Staying safe
using latex condoms correctly every time you have sex. However, know that you can
still get syphilis from sores in areas not covered by a condom.
For women, symptoms of chlamydia, gonorrhea and syphilis don’t always appear given the sometimes silent nature of early stages of infection. But symptoms can include abnormal vaginal discharge or bleeding; burning sensation while peeing; rectal pain, discharge, itching or bleeding; or painful bowel movements. Early signs of syphilis are sores that can be firm, round and painless.
High-risk factors include previously having an STI, new or multiple sex partners, sex with a person who has an STI, or inconsistent condom use. Higher-risk women should be screened again during the third trimester. All pregnant women should be screened for syphilis early, with a second screening in the third trimester recommended for higher-risk women, the CDC advises.
If you’re pregnant and “suspect you could have an STI, consult with your primary care physician or obstetrician and get tested and then treated if you are infected,” Ryckman said. “If you are infected with an STI, make sure to discuss your risks for pregnancy complications with your obstetrician.”
Below are the CDC’s resources for more information and clinic referrals:
• CDC-INFO
1-800-CDC-INFO (800-232-4636)
TTY: 1-888-232-6348
919-361-8488
this page to use the CDC’s “Find an STD testing site near you” function.