Colombian and American researchers show that infection with Zika during the 3rd trimester of pregnancy does not increase the risk of microcephaly.
The first trimester of pregnancy would be the most critical period in case of infection with the Zika virus, according to a study conducted in Colombia and published this Thursday in the New England Journal of Medicine.
Researchers at the Colombian Institute of Health, in collaboration with the American Centers for Disease Control and Prevention (CDC), have not observed any cases of microcephaly in children born to infected mothers at the end of their life. pregnancy. They thus suggest that infection with the Zika virus during the 3th trimester of pregnancy does not favor the occurrence of the birth defect.
1,850 pregnant women studied
In Colombia, nearly 12,000 pregnant women were reportedly infected with the virus between August 2015 and April 2016. To assess the risk of microcephaly, the research team studied the medical records of 1,850 women. Zika virus infection was confirmed biologically in 326 of them.
The researchers specify that 532 women reported having exhibited the signs of Zika (rash with or without fever, joint pain) during the 1er trimester of pregnancy, 702 during the 2th trimester and 616 at the end of their pregnancy. In the latter, more than 90% of them have given birth and none have given birth to a child with a brain defect. Women infected during the first 6 months of their pregnancy have still not given birth, the authors add, adding that they expect an upsurge in cases of microcephaly in the weeks and months to come.
These results thus seem to confirm that fetuses infected with the Zika virus during the first trimester of pregnancy have an increased risk of developing microcephaly, as the Pasteur Institute showed last March and a recent study published in May.
Young women 3 times more affected
In addition, the researchers found that young women between the ages of 15 and 29 were the first targets of the Zika virus in Colombia. Infection with this virus was indeed 3 times greater in women than in men of the same age. “Given that 73% of pregnancies in Colombia concern young women of this age, the high incidence of Zika infection is very worrying and underlines the urgent need to strengthen prevention among this age group”, underline the authors. .
Since the arrival of the Zika virus in Colombia in August 2015, more than 65,700 people have reportedly been infected, but only 2,485 cases have been confirmed biologically. But these data do not reflect the extent of the epidemic, note the authors recalling that 80% of infections are asymptomatic.
As a result, pregnant women carrying the Zika virus without knowing it do not benefit from adequate care and escape medical supervision.
.
