Zika virus and pregnancy: Importance of preconception counselling and Zika testing for expecting women

Zika virus preconception counselling is very important for couples planning pregnancy residing in a geographical region with active transmission of the virus. Proper information, knowledge, and preconception counselling are essential to prevent Zika virus infection that may affect the outcome of pregnancy as well.

Preconception counselling should help couples make informed decisions on planning the pregnancy, protection during pregnancy, and postnatal care.

Before planning pregnancy by having unprotected sex, ideally, men must wait for at least 6 months and women for at least 2 months post-exposure to the virus with or without symptoms or after travelling to an endemic area. The virus is transmitted not only by mosquito bites but also by sexual contact.

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According to the CDC (Centre for Disease Control), animal studies have shown that sexual transmission causes more damage to the developing foetus than infection acquired by the pregnant mother through mosquito transmission.

The incubation period and the period during which the infected mosquito can carry and spread the infection are still under research. Most of the individuals affected by the disease will be asymptomatic or symptoms may be mild like fever, rash, red eyes, and joint pain.

Zika virus transmission to the foetus can happen at any time during pregnancy and may result in birth defects like microcephaly, defective brain development, and neurological issues. A child born with minimal birth defects may develop vision disorder, hearing loss, and impaired growth in the future. There may be other pregnancy-related issues,like miscarriage and stillbirth. Hence, it is very important to stay protected throughout the pregnancy. Vaccines and medicines for the virus are not yet developed and are still under research.

Individuals residing in the Zika endemic area would have developed antibodies against the virus. Testing of antibodies doesn’t differentiate between current infection and past infection. The women can test for antibodies before planning pregnancy and compare the values in case there is an infection or exposure post-pregnancy. If the values are negative before pregnancy and the antibodiesdevelopafter pregnancy, it may be possibly due to a recent Zika virus infection. But if the antibodies are present even before the pregnancy, then we will not be able to decide if the woman is safe to become pregnant at present, since it is not possible to conclude if the antibody has been raised due to a recent infection, or a past infection.

The antibodies may also be positive due to cross-reactivity with infection of a similar family of virus-like dengue virus, leading to false positivity. Detection of RNA PCR may sometimes give false negative reports due to the presence of less viral load. So, a negative report mandatorily doesn’t eliminate the presence of infection. Hence, it is important to be protected throughout pregnancy.

Prevention includes protection from mosquito bites by using air conditioners at home and workplace, sleeping under mosquito nets, and installing mesh windows and door screens to prevent mosquitoes from entering the premises. Wearing long-sleeved dresses and full pants covering arms and legs, applying permethrin over the dress will add extra protection.

Using EPA-approved repellents with any one of the active components like DEET, IR3535, 2-undecanone, picaridin, and eucalyptus oil is safe during pregnancy. Reapplication of the repellents as per manufacturer instruction is important. Mosquito breeding sites around the premises, like stagnant water from flowerpots, pools, unused tyres, and buckets, must be cleared at regular intervals.

If a pregnant woman is living in an area where the Zika virus is not endemic, then it is recommended not to travel to an area with active Zika virus transmission. If the partner of the pregnant woman lives or has travelled to an area with active transmission of the Zika virus, then it is recommended that they use a barrier method to have sexual intercourse or abstain from sexual contact during pregnancy.

(With inputs fromDr Manisha Arora, Director - Internal Medicine at the CK Birla Hospital Delhi, and Dr R Lakshmipriya, Senior Consultant Microbiologist and Molecular Biologist at the Metropolis Healthcare Limited)