D.C. Hospital Makes Frightening Discovery About Zika in Pregnancy

Doctors at a District of Columbia hospital are concerned about how health workers monitor pregnant women who have been infected with Zika, saying that these women can have a false sense of security for weeks before some tests show any sign of brain damage to a fetus that might influence their decision to have an abortion.
The hospital, Children's National Medical Center, treated a 33-year-old woman who had apparently normal ultrasounds until 19 weeks into her pregnancy, even though doctors found when testing her blood that the virus lingered for 10 weeks after she was initially infected. The woman chose to have an abortion at 21 weeks, when doctors gave her a prognosis indicating that the fetus had developed severe brain damage.
Current recommendations by the Centers for Disease Control and Prevention encourage doctors to conduct ultrasounds and to look for brain calcification, but the findings from Children's National indicate this may not be enough.
"Our patient had several such ultrasound studies which remained free of either of those biomarkers," Dr. Adre du Plessis, director of the hospital's Fetal Medicine Institute and co-author of an article about the case that appeared online Wednesday in the New England Journal of Medicine, said in a call with reporters Wednesday. "This led to a false reassurance to the mother, and when we performed an MRI it was clear there was significant impairment in development of major structures in the brain and evidence of injury."
Researchers are looking to find out as early as they can into a pregnancy whether a fetus will develop abnormalities from Zika infection. In many states, abortions are illegal if they are conducted after 20 weeks. "This delayed diagnosis of brain infection may put mothers for whom termination is an option outside of the legal limits of such a procedure," du Plessis said.
Doctors are concerned about Zika, which is spread primarily through mosquitoes, because it has been linked in Brazil to a surge of microcephaly cases, a birth defect that causes babies to be born with unusually small heads and possible cognitive impairments. Several people have become infected with the virus and returned to the U.S. after traveling through Latin America, and upon discovering abnormal brain scans, pregnant women have had abortions. Scientists are increasingly learning more about the virus, including that it can be transmitted sexually.
The CDC has advised pregnant women not to travel to Latin America. If they do, the agency says to wear insect repellent and to require male partners who have traveled to these areas to wear condoms during sex, as researchers don't know how long the virus lingers in semen.
The woman treated at Children's National, who is Finnish, became infected with Zika after a trip to Mexico, Guatemala and Belize with her husband, during which she was 11 weeks pregnant. She and her husband became sick after returning to their home in Washington. with the same kinds of mild symptoms that doctors have observed in people who have any symptoms of Zika: eye pain, rash, muscle pain and fever that lasts for five days.
Ultrasounds conducted at 13, 16 and 17 weeks showed no signs of possible microcephaly or other issues with brain development, but blood tests showed fragments of Zika in the woman's blood. Doctors did not detect severe abnormalities in the fetus' brain until the 19-week ultrasound, a time frame that is significant for a fetal brain because it grows larger and more complex. Portions of the brain were thin and its growth was not keeping up with the pace of the skull's growth. Still, doctors did not make an official diagnosis of microcephaly because the fetus' head circumference was not small enough to meet the threshold – even though the fetus' brain weighed 30 grams after the abortion, less than a typical size, which is 49 grams.
An MRI conducted during the 20th week showed that the portion of the brain that controls decision making, as well as the portion that detects vision, hearing and touch, were wasting away. The day the woman had the abortion, 21 weeks into the pregnancy, she still tested positive for Zika after the procedure, but 11 days later, her blood, urine and saliva tested negative. High concentrations of the virus were found in the aborted remains, including in the brain umbilical cord and placenta, and smaller concentrations were found in the muscle, lung, spleen and amniotic fluid. The virus found in the brain remained infectious when it was tested.
"The high amount of virus in the fetal brain and the placenta are concerning and suggest that the virus may be able to hide from the immune system there," Dr. Roberta DeBiasi, chief of the hospital's division of infectious disease and co-author of the New England Journal of Medicine study, said in a statement. "Equally concerning is Zika's apparent preference for fetal brain cells, where it replicates efficiently and can do damage silently."
The researchers say it is still difficult to know how much the virus affects a fetus at different stages of pregnancy, if at all. They cautioned against drawing any conclusions about a fetus' development before further testing.
"There may be a tendency to say, 'We aren't sure but it doesn't look right,'" du Plessis said. "That could lead to decisions that are not well informed."