Medical monitoring and examinations are important measures to monitor the health of the mother and baby throughout the pregnancy. Among these procedures, screening for sexually transmitted infections (STIs), for example, integrates prenatal care and helps identify infections that often do not present symptoms. With this, it is possible to begin treatment and/or appropriate follow-up.

According to the World Health Organization (WHO), more than 1 million curable sexually transmitted infections are acquired every day in the world, and most of them have no apparent symptoms. In 2022, the entity estimated that around 1.1 million pregnant women were diagnosed with syphilis. When not identified and treated during prenatal care, the infection may be associated with some complications during pregnancy or childbirth, such as prematurity or low birth weight.

In Brazil, syphilis is one of the most monitored infections during prenatal care and a point of attention in maternal and child health policies. Data from the Ministry of Health indicate that, between 2005 and June 2025, 810,246 diagnoses of syphilis were recorded in pregnant women in the country. In 2024 alone, the rate was 35.4 cases per 1,000 live births, which corresponds to around 89.7 thousand records in the year, maintaining a growth trend, with an increase of 3.2% compared to 2023.

“Sexually transmitted infections often do not present clear symptoms, which can lead to them being discovered late, including during pregnancy. Therefore, expanding access to diagnosis is a way of taking care of women’s health and reducing the risk of transmission to the baby”, says Dr. Márcia Felician, obstetrician gynecologist and doctor on the Genitoscopy and Laser team at Dasa, a diagnostic medicine company in Brazil.

ISTs what can affect the baby

In addition to syphilis, other STDs are also a concern. The WHO warns that infections such as HIV, hepatitis B and C, herpes and HPV can directly impact the maternal health and neonatal, being associated with stillbirth, neonatal death, sepsis, neonatal conjunctivitis, congenital malformations and developmental complications in the first months of life.

In the Brazilian context, the study “Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project”published in the International Journal of Gynecology & Obstetrics, carried out in 2022 with 2,728 pregnant women, found a 21% prevalence of STIs, including chlamydia (9.9%), gonorrhea, Mycoplasma genitalium e Trichomonas vaginaliswith even higher rates in the Southeast region (23.3%). In relation to HIV, recent data from the Ministry of Health indicate a 7.9% drop in cases among pregnant women in 2025, with around 7,500 records in the year.

“When not diagnosed and treated in time, some infections can go through pregnancy and affect the baby, leading to complications such as prematurity, low birth weight or neonatal infection. Early diagnosis is an essential step towards maternal and child protection”, reinforces Dr. Márcia Felician.

The problem of the “silence” of STIs

One of the main challenges in controlling these infections is that many of them have no symptoms or cause non-specific signs. This means that diagnosis often happens late, sometimes only during the prenatal or after birth, increasing the risk of preventable complications.

For this reason, international organizations and health authorities recommend screening pregnant women for STIs as an essential part of prenatal care, especially in countries with a high incidence of these infections.

How to prevent it: when and what tests to do

Prevention involves different fronts. Correct and consistent use of condoms remains one of the most effective ways to reduce the risk of STIs. Additionally, safe and effective vaccines are available for hepatitis B and HPV, considered important advances in protecting sexual and reproductive health. Still, testing remains central, especially for women who are pregnant or planning to become pregnant.

Lack of time, difficulty traveling and stigma still keep many people away from testing. In this scenario, the search for models that take care to people’s homes, with more comfort, privacy and practicality, is growing. In Brazil, the check-up of STIs is an example of this approach aimed at early diagnosis, focusing on laboratory tests to detect sexually transmitted infections. The panel mainly includes tests for:

• HIV;
• Syphilis;
• Hepatitis B;
• Hepatitis C;

These infections are among those that can have significant impacts during pregnancy when they are not identified and treated in time. “Facilitating access to the exam, including the possibility of carrying it out at home, can help break down barriers and expand screening, something essential to protect the health of the mother and baby”, highlights Dr. Márcia Felician.

By Fernanda Bertin Quinta