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Infection with the Zika virus in pregnancy represents a risk for the baby, because the virus can cross the placenta and reach the baby's brain and compromise its development, resulting in microcephaly and other neurological changes, such as lack of motor coordination and cognitive impairment.
This infection is identified through the signs and symptoms presented by the pregnant woman, such as the appearance of red spots on the skin, fever, pain and swelling in the joints, as well as through tests that must be indicated by the doctor and that allow the identification of the virus
Symptoms of Zika virus in pregnancy
A woman infected with the Zika virus during pregnancy has the same signs and symptoms as everyone else who has been infected with the virus, such as:
- Red spots on the skin;
- Itchy body;
- Fever;
- Headache;
- Redness in the eyes;
- Pain in the joints;
- Swelling in the body;
- Weakness.
The virus incubation period is 3 to 14 days, that is, the first symptoms begin to appear after that period and usually disappear after 2 to 7 days.However, even if the symptoms disappear, it is important that the woman goes to the obstetrician-gynecologist or infectious disease so that tests are carried out and the risk of transmission of the virus to the baby is verified.
Although the baby's brain impairment is greater when the mother has Zika in the first trimester of pregnancy, the baby can be affected at any stage of pregnancy. Therefore, all pregnant women must be accompanied by doctors during prenatal care and must protect themselves from the mosquito to avoid catching Zika, in addition they must also use condoms, when the partner has symptoms of Zika.
Risks and complications for the baby
The Zika virus manages to cross the placenta and reach the baby and, as it has a predilection for the nervous system, it travels to the baby's brain, interfering with its development and resulting in microcephaly, which is characterized by a head circumference smaller than 33 centimeters. As a result of poor brain development, the baby has cognitive impairment, difficulty seeing and lack of motor coordination.
Although the baby can be reached at any stage of pregnancy, the risks are greater when the mother's infection occurs in the first trimesters of pregnancy, because the baby is still in the development stage, with a greater risk of miscarriage and death of the baby still in the uterus, while in the last trimesters of pregnancy the baby is practically formed, so the virus has less impact.
The only ways to know if the baby has microcephaly are through ultrasound where a smaller brain perimeter can be observed and by measuring the size of the head as soon as the baby is born. However, no test can prove that the Zika virus was present in the baby's bloodstream at any time during pregnancy. Studies carried out verified the presence of the virus in the amniotic fluid, serum, brain tissue and CSF of newborns with microcephaly, indicating that there was infection.
How the transmission happens
The main form of transmission of the Zika virus is through the bite of the Aedes aegypti mosquito, however it is also possible that the virus is transmitted from mother to child during pregnancy or at delivery. Cases of Zika virus transmission through unprotected sexual contact have also been described, but this form of transmission still needs to be further studied to confirm it.
How the diagnosis is made
The diagnosis of Zika in pregnancy should be made by the doctor based on the assessment of signs and symptoms presented by the person, as well as by performing some tests. It is important that tests are performed during the period of symptoms, with a greater probability of identifying the circulating virus.
The 3 main tests that are able to identify that the person has Zika are:
1. PCR molecular test
The molecular test is the most used to identify Zika virus infection, because in addition to indicating the presence or absence of infection, it also reports the amount of circulating virus, which is important for the indication of treatment by the doctor.
The PCR test is able to identify virus particles in the blood, placenta and amniotic fluid. The result is more easily obtained when it is performed while the person has the symptoms of the disease, which varies between 3 and 10 days. After this period, the immune system fights the virus and the less viruses are present in these tissues, the more difficult it will be to reach the diagnosis.
When the result is negative, which means that no Zika virus particles were found in the blood, placenta or amniotic fluid, but the baby has microcephaly, other causes for this disease must be investigated. Know the causes of microcephaly.
However, it is difficult to know whether the woman has had Zika so long ago that the immune system has managed to remove all traces of the virus from the body. This could only be clarified by carrying out another test that assesses the antibodies formed against the Zika virus, which so far does not yet exist, although researchers around the world are working on this.
2. Quick test for Zika
The rapid Zika test is done for the purpose of screening, as it only indicates whether or not there is infection based on the assessment of the circulating antibodies in the body against the virus. In the case of positive results, a molecular examination is indicated, while in negative tests the recommendation is to repeat the examination and, if there are symptoms and the rapid negative test, the molecular test is also indicated.
3. Differential examination for Dengue, Zika and Chikungunya
As Dengue, Zika and Chikungunya cause similar symptoms, one of the tests that can be performed in the laboratory is the differential test for these diseases, which consists of specific reagents for each disease and provides the result in more or less than 2 hours.
See more about Zika's diagnosis.
How to protect yourself from Zika in pregnancy
To protect themselves and avoid Zika, pregnant women should wear long clothes that cover most of the skin and use repellent every day to keep mosquitoes away. See which repellents most in pregnancy are indicated.
Other strategies that may be useful are planting citronella or lighting citronella scented candles nearby because they keep mosquitoes away. Investing in the consumption of foods rich in vitamin B1 also helps to keep mosquitoes away because it alters the smell of the skin, preventing mosquitoes from being attracted by their smell.
Created by: Tua Saúde Editorial Team
Bibliography>
- NATIONAL INSTITUTE OF HEALTH FOR WOMEN, CHILDREN AND ADOLESCENTS. Pregnancy and care with the Zika virus. Available in: . Accessed on 03 Jan 2020
- PIMENTA, Mariana et al. Zika virus and pregnancy Zika virus and pregnancy. Acta Obstet Ginecol Port. Vol 10. 2 ed; 92-94, 2016
- FIOCRUZ. DPP® Zika IgM / IgG. Available in: . Accessed on 03 Jan 2020