The Royal College of Obstetricians and Gynaecologists (RCOG) are fully aware of the Zika virus outbreak in South and Central America and the Caribbean, which has been declared a "public health emergency of international concern" by the World Health Organization (WHO).
The Zika virus is an emerging mosquito-borne virus, which isn't harmful in most cases. However, it may be harmful for pregnancies, as it's been potentially linked to birth defects, specifically microcephaly (a smaller head than expected which can be due to abnormal brain development).
Whilst it remains important for pregnant women travelling to or returning from infected areas to take necessary precautions, Public Health England is stressing that any public health risk to the wider population and pregnant women in this country is negligible, as the mosquito that transmits the virus is not found in the UK. Almost all cases of Zika virus are acquired by mosquito bites, although a small number of cases of sexual transmission of Zika virus have been reported, and in a limited number of cases, the virus has been shown present in semen.
Professor Alan Cameron, vice president for Clinical Quality at the Royal College of Obstetricians and Gynaecologists (RCOG), said:
“We fully support the advice that pregnant women should avoid travelling to countries where Zika virus outbreaks are ongoing, in order to reduce the potential risk to their babies. This includes women travelling to Brazil for the 2016 Olympic and Paralympic Games.
“In addition, anyone travelling to an area with active Zika virus transmission, including Brazil, should ensure they use effective contraception to prevent pregnancy and following their return to the UK, follow the advice on avoiding pregnancy, even if they haven’t experienced any symptoms of Zika virus infection.
“Pregnant women who must travel, or choose to travel, to a country with active Zika virus transmission should take all necessary precautions to minimise the chances of mosquito bites, and use condoms for the duration of pregnancy to prevent the risk of sexual transmission. Insect repellents with concentrations of DEET up to 50% are commonly available and are safe for pregnant women.
“Women who are pregnant, and those trying to conceive, who have recently returned to the UK from countries with an active Zika transmission should inform their GP, midwife or obstetrician that they may have been exposed to the Zika virus, even if they do not have any symptoms.
“As a precaution, obstetricians across the UK have been provided with national guidelines on how to assess pregnant women with a history of travel during pregnancy to areas with active Zika virus transmission. This includes taking a detailed travel history, providing regular ultrasound scans and referral to specialist fetal medicine service if required.
“The RCOG is monitoring this evolving situation closely and will publish new information for health professionals as it emerges”.
Notes to editors
Q&As related to Zika virus and pregnancy
What are the symptoms of Zika virus?
Most people infected with Zika virus do not feel unwell. If symptoms do occur, people may experience a mild, short-lived illness for 2-7 days. Symptoms can include a slight fever, joint pain, an itchy rash, conjunctivitis (red eyes), headache, eye pain and muscle pain.
What is the advice for pregnant women planning to travel to countries with active Zika virus transmission?
In the UK, the advice is that pregnant women should consider avoiding travel to countries with active Zika virus transmission, in order to reduce the risk to their babies.
What is the advice for pregnant women who have recently returned from a country with active Zika virus transmission?
Pregnant women who have recently returned to the UK from a country with active Zika virus transmission should inform their midwife or obstetrician that they may have been exposed to the Zika virus so that they can be appropriately monitored, even if they do not have any symptoms.
What is the advice for women planning a pregnancy who have visited a country with active Zika virus transmission?
On returning to the UK from a country with active Zika virus transmission, women should avoid becoming pregnant for a further 28 days, even if they haven’t experienced any symptoms – this allows for a maximum two-week incubation period (the time between exposure to an infection and the appearance of the first symptoms).
What is the advice for a woman whose partner has been to an area with active Zika virus transmission?
The risk of sexual transmission of Zika virus is thought to be very low. However, Zika virus has been identified in semen of men who have had Zika infection, and it is not known how long this can persist. If a woman’s partner has travelled to a country with active Zika virus transmission, effective contraception is advised to avoid pregnancy (and the use of condoms could be considered to prevent against infection acquisition):
- For 28 days after his return home if he had no Zika virus symptoms, either whilst abroad or within two weeks of his leaving the affected country
- For 6 months following recovery if he did experience Zika symptoms during that period
What is the advice for women who have to travel to areas with active Zika virus transmission?
Pregnant women who must travel, or choose to travel, to a country with an active Zika virus transmission should take all necessary precautions to minimise the chances of a mosquito bites.
Are DEET based insect repellents safe for use in pregnancy?
Insect repellents with concentrations of DEET up to 50% are commonly available and are safe in pregnant and breastfeeding women (and in infants and children over the age of two months).
Are pregnant women more vulnerable to the Zika virus?
There is no evidence that pregnant women are more vulnerable to acquiring Zika virus infection or that this infection causes a more serious illness in pregnant women.
Can pregnant women receive treatment for Zika virus?
There is no specific antiviral treatment for Zika virus infection, which is usually mild and short-lived. If symptoms are troublesome, a pregnant woman should be advised to get plenty of rest, drink adequate fluids and manage pain and fever with regular paracetamol and other cooling measures.
Are antihistamines safe to use in pregnancy?
If the rash is itchy and pregnant women feel they need to use antihistamines to ease their symptoms, they should check with their GP, pharmacist or midwife first. An oral antihistamine, usually chlorpheniramine, loratadine or cetirizine is likely to be recommended. These older antihistamines have been used in pregnancy for many years and are known to be safe.
Can Zika virus be passed from mothers to their babies?
Cases of maternal fetal transmission of Zika virus have been confirmed. It has been demonstrated that Zika virus can cross the placental barrier and the virus has been detected in blood and tissues of a least seven affected fetuses/infants – the mothers of six of these cases presented with symptoms consistent with Zika infection during pregnancy.
Can Zika virus be transmitted to babies through breast milk?
There is no evidence that Zika virus can be transmitted to babies through breast milk and the advice to mothers to breastfeed remains unchanged.
What advice has been given to UK doctors and midwives about the Zika virus outbreak?
The RCOG is monitoring this evolving situation closely and has worked with the Royal College of Midwives, Public Health England and Health Protection Scotland to produce interim guidelines on Zika virus in pregnancy for healthcare professionals and a flowchart (algorithm) for assessing pregnant women with a history of travel during pregnancy to areas with active Zika virus transmission. More information will be shared with healthcare professionals as it becomes available.
Will all pregnant women in the UK be tested for Zika virus?
Healthcare professionals in the UK have been advised to ask all pregnant women about their recent travel history. Only pregnant women with a history of travel to an area with active Zika virus transmission and who present with current symptoms consistent with Zika infection that began during or within 2 weeks of travel should be tested. The testing should include investigation for other travel associated infections (such as malaria, dengue fever and chikungunya) as well as Zika.
What happens if Zika virus is detected?
A pregnant woman who tests positive for Zika virus infection will be referred to a Fetal Medicine service for further assessment – this may include regular (4-weekly) fetal ultrasound scans to monitor fetal growth and consideration of fetal MRI.
What happens if a woman with travel history to a Zika infected area has a negative test or doesn’t report any symptoms?
A baseline fetal ultrasound scan will be offered to all pregnant women who have returned from areas with active Zika virus transmission, even if they have not reported any symptoms. Ultrasounds may be repeated regularly (4-weekly) - if the scan detects any abnormality, the woman may be referred to a Fetal Medicine service for further investigations.
Can microcephaly be detected on ultrasound?
A small fetal head (defined as a head circumference more than 2 standard deviations below the mean for gestational age) or brain abnormality can usually be detected from 20 weeks onwards. It’s important to remember that the majority of babies with a head circumference more than 2 standard deviations below the mean will be normal and will not have microcephaly. However referral to a specialist fetal medicine service for further investigation is recommended. Microcephaly is usually diagnosed when a baby’s head circumference is even smaller than this, and usually together with structural abnormality of the brain that can be diagnosed with specialist imaging (e.g. MRI).
At what point during a pregnancy can microcephaly be detected by ultrasound?
A diagnosis of fetal microcephaly is not usually given until a woman is around 28 weeks pregnant, and sometimes it’s not possible to make a definitive antenatal diagnosis at all.
Can babies be tested for Zika virus in the womb?
If fetal microcephaly is diagnosed then it is possible that an amniocentesis can be performed to test for Zika virus in the amniotic fluid. This decision would only be taken after careful counselling as amniocentesis is associated with a small risk of miscarriage or preterm birth and should not be performed before 15 weeks of gestation. It is important to remember that if there is a positive test for Zika virus in the amniotic fluid but no definite fetal abnormality, the likelihood of the fetus being affected is not known.
Would abortion be offered to a woman who has a fetal abnormality like microcephaly?
When a significant brain abnormality or microcephaly is confirmed, the option of termination of pregnancy should be discussed with the woman, regardless of gestation.
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Page updated on 6 July 2016