Some pregnant women with Zika
virus tend not to fare well, and neither do their fetuses, a new study finds.
Zika is a mosquito-borne
virus that can also be transmitted through unprotected sexual
intercourse. Because of concerns that the disease may increase the risk of
microcephaly (small brain size) and other developmental disorders in the
fetuses of pregnant women infected with the virus, scientists decided to
monitor the pregnancies of both healthy and infected women.
The researchers studied 88
pregnant women in Rio de Janeiro from September 2015 through February 2016,
according to the study, published Friday (March 4) in the The New
England Journal of Medicine. Of these women, 72 tested positive for
Zika virus in their blood, urine, or both. [Zika Virus
News: Complete Coverage of the 2016 Outbreak]
Among the Zika-positive
pregnant women, the most common symptoms were rash, joint pain, red eye and
headache, the researchers found. The doctors also performed a fetal ultrasound
on 42 of the women with Zika and on all of the women without Zika. Among the
Zika-positive group, 12 of them (29 percent) had fetuses with abnormalities,
compared to none of the 16 Zika-negative women.
Among the 12 fetuses with
abnormalities, two of them died — one at 36 weeks and the other at 38 weeks.
Five of the fetuses were smaller than normal (and some had microcephaly),
seven had central nervous system lesions, and seven had an abnormal amount of
amniotic fluid or cerebral or umbilical artery flow, the researchers said. One
fetus had additional problems, including microcephaly and other brain
development challenges, growth restriction and a potential clubfoot, they
added.
To date, eight of the 42 women
who participated in the ultrasound have given birth, and the ultrasonographic
findings have been confirmed, the researchers said.
"Despite mild clinical
symptoms, Zika virus infection during pregnancy appears to be associated with
grave outcomes, including fetal death, placental insufficiency, fetal growth
restriction and central
nervous system injury," the scientists said in the study.
The findings are "quite
disturbing," Dr. Anthony Fauci, director of the National Institute of
Allergy and Infectious Diseases, told reporters today (March 10) in a news
briefing.
Given that fetal abnormalities
were found in 29 percent of the Zika-positive women, it's possible there
may be "many more [abnormalities] that you don't realize until after the
birth of the baby," Fauci said.
Moreover, the study shows that
the fetuses had developmental problems even when their mothers caught the
disease late in their pregnancies.
"In all three trimesters
of pregnancy, there were definite fetal effects," Dr. Tom Frieden,
director of the Centers for Disease Control and Prevention, told reporters in
today's briefing. "What we're saying basically is that the more we learn
about Zika in pregnancy, the more concerned we are."