The current Zika issue for pregnant women is the foetal defects it can generate. The first warning signs were the microcephaly discovered during the new-born examination. The name microcephaly refers to a head circumference size which is usually lower than two standard deviations. During the first warnings made on microcephaly, the definition of this term and its limits were not completely clear so the exact number of children born with a brain damage linked to Zika virus is not precisely known, we mainly speak of children with microcephaly and with a Zika suspicion, but there are very few cases with virological proof that the baby was with Zika virus. The other raised issue is that the name microcephaly can gather a wide number of neurological abnormalities. It might be better to use the term "congenital syndrome of Zika" referring to other foetal viral infection. The head circumference size of the child mainly relies on its brain development. We can have a small head circumference with a brain more or less damaged and more or less sick, so the size itself is not enough to give the neurological prognosis of the child at mid- and long-term. The prognosis will be linked to damages to the cerebellar for instance, or to the corpus calosum, to the ventricles size, to the gyration anomalies or to ophthalmologic damages that have been described until now in Zika infections. Currently, we are beginning to describe the antenatal semiotic of the infection by Zika virus and the regular publications help us improve our knowledge, one feature of Zika seems to be the damages of the cerebellar, of the corpus calosum, of the neuronal migration and the ophthalmologic defects. According to the level of those damages, the prognosis of the child will be different. It is very difficult today to say what long term future those children will have when they are 6 months, 2 years, 10 years old, as we don't have a hindsight yet, we can only get close to another known neurological pathology to try to estimate a prognosis. One of the difficulty we can face with prenatal diagnosis, is that there can be cases easy to evaluate in terms of diagnosis, for instance if there is a major brain damage with a significant destruction, then we know it is a disastrous prognosis. The more difficult issue that we must answer is the future of children who have moderate stroke or who even show no symptom during the ultrasound or the prenatal MRI, and for them we don't even know if they can have developmental disorder at mid- or long-term. Process leading to brain damages are unknown, there are hypothesis, tracks, animal models which are being developed to try understanding what mechanism makes the virus induces the foetus development abnormalities, it might be a damage of the neuronal stem cells which stop them from multiplying and so stops the foetal growth and lead to microcephaly it might be inductions of apoptotic process : foetal inflammatory reaction that provokes the destruction of the brain. Hypothetically, microcephaly can be due to two things : to an absence of foetal cerebral development by a damage of stem cells and so an absence of cells replication which is why there is no growth and to a destruction of the brain that will, at one point, make that the cerebral growth will stop. The first question a patient will ask us once we've made the Zika infection diagnosis during her pregnancy, is to what risk the foetus can be affected ? There is always two issues raised : first, what is the rate of transmission from the mother to the child ? Can a mother be infected without the foetus being infected ? Today we don't know the mother-to-child transmission rate. If we look at the cytomegalovirus for instance, the mother-to-child transmission is weak during the first trimester and then raise, but for rubella, the transmission rate is very high during the first trimester. Currently, we don't have the answer about the mother-to-child transmission rate. Second question : when the foetus is infected, what is the probability of severe damages ? There is no prospective studies that gives an answer. There are several recent studies on mathematical calculation to estimate those risks. One of the most relevant study published in Lancet not so long ago by M. Cauchemez and the Polynesian team, shows that when a woman is infected during the first trimester, the risk to have a child with microcephaly would be 1%, which is a relative risk of 50 compare to a basic risk. Nowadays, we don't have more precise data, and according to this study we may have numbers of children with microcephaly less important than what we feared at the beginning, but it is a very controversial subject. One of the question asked by patient is about desire for pregnancy. Currently, it is advised to be vigilant for women who want to get pregnant in areas where there is an outbreak, the patient must not be infected or bitten by mosquitoes. There is also the issue of sexual transmission, with proven cases of transmission from men to women by the virus in semen, it has been showed that the virus can remain quite a long time in semen. What are the current recommendations ? if you live in mainland and your male partner comes back from a trip in a country where there is the outbreak, you should have safe sex with your partner if she's pregnant until the end of the pregnancy. And if there is a desire of pregnancy, to postpone it during 1 to 3 month, depending on the recommendations, because there are cases where the virus has been found after 60 days in the semen. About a woman who has a Zika infection, it will take up to eight weeks for her to get pregnant again without risks. Currently, we consider that Zika infection is immunising, so a patient that has already been contaminated by the Zika virus has very few chances to do a second reaction to Zika and to have a sick baby and even if she does a second Zika infection, the probability for the baby to be sick is very low. We consider that in countries where there is a massive Zika outbreak now, the majority of women will catch it, we have a 60% to 80% rate, and once they catch it, they will be protected for their next pregnancies, but they still have to be careful with mosquitoes as there are other infectious agents that can be transmitted by them. Currently, in mainland, in metropolitan France and in Europe, we are not much exposed to Zika outbreak per se, but we are mainly exposed to women questions who have planned to go to a place where there is an epidemic or who have a husband who have been there. We have to handle fear more than disease. We should be honest with the patients and tell them that there are many questions still unanswered, that there is an important risk that the baby will have sequelae of a Zika infection during pregnancy. We don't know the exact numbers. We might know them in a few months or a few years. That they should avoid, for the sake of prudence, to go to places where there is an outbreak because even if they take all precautions against mosquitoes, they can still be bitten by an infected mosquito. We have to inform the public without falling into psychosis, paranoia and lead to anxiety, we have to give a clear and precise information. My opinion is that a pregnant woman must avoid to go to tropical countries as there is not only Zika, but also malaria that can have tragic consequences for pregnancy. So to advise a patient to avoid tropical countries during pregnancy seems to be a basic precautionary measure. Then we must be able to take care for patients with the elements we have, therefore, the most important for doctors, gynaecologist, obstetrician, paediatrician, radiologist, everyone who takes care of the disease, is to keep updated day after day, weeks after weeks on the evolution of knowledge of the disease as there is a huge number of publications all the time, it's difficult to read everything, but you have to learn the broad lines of the evolution of knowledge to be able to take care correctly of patient with the right degree of vigilance.
