Getting pregnant in the time of Zika

MAPS - Zika maps-Optimized

Areas where Aedes aegypti mosquitoes are or have been previously found in the U.S. – Image: CDC

With the Centres for Disease Control and Prevention (CDC) confirming that Zika virus infection during pregnancy causes microcephaly and other severe foetal brain defects, the federal health officials in the U.S. are not sure whether to advise women living in areas where the virus is circulating locally to delay pregnancy. The virus is circulating locally in Puerto Rico, the United States Virgin Islands and American Samo. About 475 people are known to have the virus in American territories, including 58 pregnant women.

According to the CDC, areas where Aedes aegypti mosquitoes are or have been previously found in the U.S. go up to 30 States. It, however, makes it clear that the maps are not meant to represent risk for spread of disease. But places like Florida, Louisiana and Texas are particularly at risk.

Sexual transmission

There is evidence to suggest that Zika virus can spread during sex from a man infected with Zika to his partners even when the man has symptoms, before symptoms start, and after symptoms end. Though it is known that the virus can stay in semen longer than in blood, it is known for how long the virus can stay in semen in those who been infected. Since the virus can be present in semen much longer than in blood, men might have a negative blood test but still have Zika virus in their semen. “Testing blood or semen is not recommended to determine the risk of sexual transmission of Zika virus,” notes CDC.

While transmission from man to woman is known, currently there is no evidence to suggest that women can transmit Zika virus to their sex partners. Transmission of the virus to partners indulging in oral sex is also not known; it not known if the virus can be passed on through saliva. Hence, couples should use a condom every time they have sex and this includes vaginal, anal and oral sex, notes CDC.

The couple should abstain from sex for at least six months after symptom onset when a man has been diagnosed with Zika or had symptoms of Zika. Likewise, the couple should abstain from sex for at least eight weeks after symptom onset when woman had symptoms or disease before attempting conception. The abstinence should be at least eight weeks if the man has travelled to an area with Zika outbreak before attempting conception, says an April 1 issue of Morbidity and Mortality Weekly Report.


Since 80 per cent of adults remain asymptomatic after being infected with Zika virus, the key question is whether women who are pregnant or planning to get pregnant run a risk of delivering babies with microcephaly? It becomes all the more tricky as there are no specific tests to determine if a baby will be born with microcephaly.  Ultrasound scans in the third trimester of pregnancy can sometimes identify the problem, notes a March 10 paper in the journal New Microbiologica.

For now, “we do not have a recommendation to not become pregnant,” Dr. Thomas R. Frieden, Director of CDC said at a “Zika summit” held recently at the CDC headquarters in Atlanta. “We do recommend access to contraception.”

But access to contraception is a problem in Latin America, which has the one of the most restrictive policies for reproductive services. Besides poor quality of sex education, voluntary abortion is outlawed in several Latin America countries. Similar problems arise in the United States, especially for poor women who lack affordable access to reproductive services. According to an April 13 paper in the Journal of the American Medical Association, some “States in the U.S. have restrictive abortion laws, have withdrawn funding for Planned Parenthood, or have refused to expand Medicaid under the Affordable Care Act. Moral and health concerns arise if a poor woman chooses to avoid pregnancy, but government impedes her access to affordable reproductive services.”

It is important to note that pregnant women who are infected with the virus are only at a higher risk of having babies with such health problems.  It does not mean that all pregnant women with Zika virus infection will have babies with health problems. For instance, most babies conceived during Zika epidemics in Brazil and other Latin American countries where Zika virus is endemic have been born healthy.

Yet, in mid-January, 2016, health ministers from Brazil, Columbia, Ecuador and Puerto Rico, among others, advised women to temporarily postpone pregnancy for six months to two years in the face of the Zika outbreak. El Salvador urged women to delay pregnancy until 2018. But an April 5 paper in the journal Clinical Infectious Diseases stated that these recommendations are “very difficult to implement as up to 56 per cent of pregnancies in the region are unintended”.

Dr. Marcos Espinal, who directs the Zika response of the Pan American Health Organization (an arm of the World Health Organization), told The New York Times that he thought advising women to avoid conception during an epidemic’s relatively brief peak months, as Colombia did, “is sound advice.”

However, the WHO’s stated policy is different. “Whether and when to become pregnant should be a personal decision, on the basis of full information and access to affordable, quality health services,” it says.

Dr. Denise J. Jamieson, a medical officer at the Division of Reproductive Health, CDC, told The New York Times:  “Birth defects are a rare complication of Zika infection. Even during an epidemic, most women will have healthy babies.”

Generally, people infected with dengue develop immunity against the serotype they were infected with but it is not clear if people infected with Zika virus enjoy the same protection. While it is not clear the duration  that patients remain immune once infected, on April 13 WHO tweeted: “We don’t know if there is immunity conferred.”