Health · Medical Research · 1 hr ago
Twice-during-pregnancy STI testing linked to fewer premature births
A clinical trial at four public clinics in South Africa tested more than 2,200 pregnant women for chlamydia, gonorrhea and trichomoniasis.
These treatable sexually transmitted infections have been linked to premature birth and low birth weight.
About 27% of women tested at the start had at least one infection, and four in five infected women had no symptoms.
Women tested twice during pregnancy had a 23% lower risk of premature birth than women receiving usual care, who were tested only if symptoms appeared.
Testing once was not linked to a lower risk, and the twice-tested group did not have a statistically significant reduction in the combined outcome of premature birth and low birth weight.
The findings suggest repeated testing could help identify infections that might otherwise go unnoticed, but researchers say the best timing and who benefits most remain unclear.
Testing pregnant women twice for three common sexually transmitted infections was linked to a 23% lower risk of premature birth in a clinical trial.
The trial included more than 2,200 pregnant women at four public clinics in South Africa.
The infections tested for were chlamydia, gonorrhea and trichomoniasis.
Testing only once was not associated with a lower risk of premature birth.
The twice-tested group did not have a statistically significant reduction in the combined outcome of premature birth and low birth weight.
- Who
- More than 2,200 pregnant women took part in the trial.
- What
- Researchers studied whether testing for three sexually transmitted infections during pregnancy could reduce premature births.
- When
- The article was published on November 4, 2026. Participants were tested at their first prenatal visit, and some were tested again at 30 to 34 weeks.
- Where
- Four public clinics in South Africa.
- Why
- The study examined whether detecting and treating infections, including those without symptoms, could reduce the risk of premature birth.
This story does not have two clearly opposing sides.
The University of Pennsylvania issued a press release about the study.
Infobae published its report on the findings.
- Infections tested
- Chlamydia, gonorrhea and trichomoniasis
- Trial participants
- More than 2,200 pregnant women
- Study location
- Four public clinics in South Africa
- Twice-tested group
- Premature birth risk was 23% lower
- Initial screening
- About 27% tested positive for at least one infection
- Third-trimester retesting
- About 9% tested positive for an infection
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What people are saying
This study suggests that testing for STIs during pregnancy could help us detect and treat infections that would otherwise go unnoticed, and that repeating testing more than once could be important for reducing the risk of premature birth
Because most of the infections we found did not cause symptoms, waiting for them to appear could mean missing the opportunity to intervene
The results give us an important signal, but they do not resolve the question of how often pregnant women should be tested