Six Percent of Completed Pregnancies Affected by Zika-Related Defects: CDC
"This is an important study. It shows that the rate of microcephaly and other fetal malformations related to Zika is similar among babies born in the United States – whose mothers were infected during travel to a dozen countries with active Zika transmission – to the estimated rate in Brazil," said CDC Director Dr. Tom Frieden.
In a new report published in the Journal of the American Medical Association, CDC's scientists used preliminary data from the US Zika Pregnancy Registry (USZPR) to estimate that 6 percent of completed pregnancies following Zika virus infection were affected by one or more birth defects potentially related to Zika virus infection during pregnancy. The report combined data from the continental United States and Hawaii, according to CDC's Dec. 15 release.
As of Sept. 22, 2016, there were 442 women with possible Zika virus infection in the USZPR who had completed their pregnancies. Twenty-six of the completed pregnancies, 6 percent, were reported to have one or more of the birth defects potentially related to Zika virus infection during pregnancy. "Among women infected with Zika in the first trimester of pregnancy, 11 percent were reported to have fetuses or infants with birth defects, which is consistent with previous modeling estimates. The proportion of pregnancies with birth defects was similar for pregnant women who did or who did not experience symptoms, about 6 percent in each group. The 18 infants with a finding of microcephaly represent 4 percent (18/442) of the completed pregnancies; this prevalence is substantially higher than the background prevalence of microcephaly in the United States of about 7 per 10,000 live births, or about 0.07 percent of live births," CDC reported.
The 26 birth defects occurred among fetuses/infants of pregnant women who were exposed to Zika virus during their pregnancies in the following locations with active Zika virus transmission: Barbados, Belize, Brazil, Colombia, Dominican Republic, El Salvador, Guatemala, Haiti, Honduras, Mexico, Republic of Marshall Islands, and Venezuela.
"This is an important study. It shows that the rate of microcephaly and other fetal malformations related to Zika is similar among babies born in the United States – whose mothers were infected during travel to a dozen countries with active Zika transmission – to the estimated rate in Brazil," said CDC Director Dr. Tom Frieden, M.D., MPH. "Zika poses a real risk throughout pregnancy, but especially in the first trimester. It's critical that pregnant women not travel to areas where Zika is spreading."