International Zika study to enrol 10,000 pregnant women

The US National Institutes of Health (NIH) and Fundacao Oswaldo Cruz-Fiocruz (Fiocruz) have begun a multi-country study to evaluate the magnitude of health risks that Zika virus infection poses to pregnant women and their developing foetuses and infants.

The study is opening in Puerto Rico and will expand to several locations in Brazil, Colombia and other areas that are experiencing active local transmission of the virus.

The Zika in Infants and Pregnancy (ZIP) study aims to enrol as many as 10,000 pregnant women ages 15 years and older at up to 15 sites. The participants will be in their first trimester of pregnancy and will be followed throughout their pregnancies to determine if they become infected with Zika virus and if so, what outcomes result for both mother and child. The participants’ infants will be carefully followed for at least one year after birth.

The researchers plan to compare birth outcomes between mothers who were infected with Zika virus and those who were not, documenting the frequency of miscarriage, preterm birth, microcephaly, malformations of the nervous system, and other complications. The researchers also seek to compare the risk of pregnancy complications among women who have symptoms of Zika virus infection and those who are infected but do not have symptoms. Additionally, the study will evaluate how the timing of infection affects pregnancy outcomes and the role environmental influences, social determinants and other infections, such as dengue virus infection, may play on the health of the study participants and their newborns.

Women to be monitored for the duration of their pregnancies

Women participating in the ZIP study will be monitored monthly for the duration of their pregnancies and then six weeks after delivery. They will have a physical examination and be asked to provide blood, urine, saliva and vaginal swab samples at study entry and at each monthly prenatal care visit. If the participants note that they will be receiving an amniocentesis in connection with their clinical care, the research team will arrange with the participant and her obstetrician to obtain a sample of the amniotic fluid to test for Zika infection. The participants will be instructed about the signs and symptoms of acute Zika virus infection and will be asked to notify their clinic immediately if they experience symptoms. Post-delivery, a breast milk sample, if available, will be obtained for Zika testing. Infants whose mothers consent to their participation in the study will be evaluated within 48 hours of birth and again at three, six and 12 months.

“This study, in partnership with NIH, is essential to elucidating the scientific complexity of the Zika virus,” said Fiocruz President Paulo Gadelha. “It will be fundamental to developing prevention and treatment strategies against the disease.”