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Zika Research Projects List: Birth Defects Among Fetuses and Infants of US Women With Evidence of Possible Zika Virus Infection During Pregnancy

Year of publication: 2017-1

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Descriptive 0, Other

Authors: Honein MA1, Dawson AL1, Petersen EE1, Jones AM1, Lee EH2, Yazdy MM3, Ahmad N4, Macdonald J5, Evert N6, Bingham A7, Ellington SR1, Shapiro-Mendoza CK1, Oduyebo T1, Fine AD2, Brown CM3, Sommer JN4, Gupta J5, Cavicchia P7, Slavinski S2, White JL4, Owen SM1, Petersen LR1, Boyle C1, Meaney-Delman D1, Jamieson DJ1; US Zika Pregnancy Registry Collaboration


  • 1Centers for Disease Control and Prevention, Atlanta, Georgia
  • 2New York City Department of Health and Mental Hygiene, Queens, New York
  • 3Massachusetts Department of Public Health, Boston
  • 4New York State Department of Health, Albany
  • 5Virginia Department of Health, Richmond


Understanding the risk of birth defects associated with Zika virus infection during pregnancy may help guide communication, prevention, and planning efforts. In the absence of Zika virus, microcephaly occurs in approximately 7 per 10 000 live births.
To estimate the preliminary proportion of fetuses or infants with birth defects after maternal Zika virus infection by trimester of infection and maternal symptoms.
Completed pregnancies with maternal, fetal, or infant laboratory evidence of possible recent Zika virus infection and outcomes reported in the continental United States and Hawaii from January 15 to September 22, 2016, in the US Zika Pregnancy Registry, a collaboration between the CDC and state and local health departments.
Laboratory evidence of possible recent Zika virus infection in a maternal, placental, fetal, or infant sample.
Birth defects potentially Zika associated: brain abnormalities with or without microcephaly, neural tube defects and other early brain malformations, eye abnormalities, and other central nervous system consequences.
Among 442 completed pregnancies in women (median age, 28 years; range, 15-50 years) with laboratory evidence of possible recent Zika virus infection, birth defects potentially related to Zika virus were identified in 26 (6%; 95% CI, 4%-8%) fetuses or infants. There were 21 infants with birth defects among 395 live births and 5 fetuses with birth defects among 47 pregnancy losses. Birth defects were reported for 16 of 271 (6%; 95% CI, 4%-9%) pregnant asymptomatic women and 10 of 167 (6%; 95% CI, 3%-11%) symptomatic pregnant women. Of the 26 affected fetuses or infants, 4 had microcephaly and no reported neuroimaging, 14 had microcephaly and brain abnormalities, and 4 had brain abnormalities without microcephaly; reported brain abnormalities included intracranial calcifications, corpus callosum abnormalities, abnormal cortical formation, cerebral atrophy, ventriculomegaly, hydrocephaly, and cerebellar abnormalities. Infants with microcephaly (18/442) represent 4% of completed pregnancies. Birth defects were reported in 9 of 85 (11%; 95% CI, 6%-19%) completed pregnancies with maternal symptoms or exposure exclusively in the first trimester (or first trimester and periconceptional period), with no reports of birth defects among fetuses or infants with prenatal exposure to Zika virus infection only in the second or third trimesters.
Among pregnant women in the United States with completed pregnancies and laboratory evidence of possible recent Zika infection, 6% of fetuses or infants had evidence of Zika-associated birth defects, primarily brain abnormalities and microcephaly, whereas among women with first-trimester Zika infection, 11% of fetuses or infants had evidence of Zika-associated birth defects. These findings support the importance of screening pregnant women for Zika virus exposure.

General Category: Disease pathogenesis and consequences of Zika Infection

Specific Category: DISEASE PATHOGENESIS. Association with Mycrocephaly and other malformations, syndromes

Type of publication Published Article

Reference: JAMA. 2017 Jan 3;317(1):59-68. doi: 10.1001/jama.2016.19006.

Tags and Keywords: Asymptomatic individuals, Babies, Birth defects, Congenital birth defects, Microcephaly, Neurologic complications, ZIKV , United States; pregnancy register;