What is microcephaly?

Microcephaly is a condition where a baby has a head that is smaller than expected. There are many different causes for this problem, including:

• infections during pregnancy, such as rubella, cytomegalovirus, toxoplasmosis or the Zika virus
• exposure to substances that might harm the baby, such as alcohol, drugs or chemicals
• genetic problems, such as Down syndrome
• severe malnutrition during pregnancy
• problems with blood supply to the baby's brain during pregnancy

Microcephaly can affect a baby in different ways, including:

• delayed development or speech
• intellectual disability
• problems with coordination or balance
• seizures
• agitation or aggression
• problems with hearing or vision

Microcephaly is a rare condition that is only reported in 1 in 25,000 babies in Australia.

Microcephaly and pregnancy

If you are pregnant, your doctor or midwife will discuss the health of both yourself and your baby at your antenatal visits. They might not talk specifically about microcephaly, but they can advise you about how to increase your chances of having a healthy baby.

During your pregnancy, you are likely to have an ultrasound and other tests to check on your baby's health. If there are any signs of a problem, your doctor will discuss this with you. Microcephaly can generally only be diagnosed during an ultrasound in the third trimester because a smaller than expected head size will not be obvious before this time.

If your baby is suspected of having microcephaly, further tests will be performed to identify the cause. Your doctor, obstetrician, midwife or a genetic counsellor will be able to answer any questions that you might have, including how it might impact your pregnancy and what your options are. You can also ask about how this might affect your child in the future.

Diagnosis of microcephaly after birth

A diagnosis of microcephaly is made simply by measuring a baby's head. It can be more difficult to work out why the baby's head is smaller than usual, and that might need a number of tests.

Treatment for microcephaly

There is no cure for microcephaly. If your child has microcephaly, there are services and treatments that can help improve their health. As part of their treatment your child may see various health professionals such as a paediatrician, a speech pathologist, an occupational therapist or a physiotherapist, depending on their symptoms.

Microcephaly and Zika virus

Zika virus is an infection that is spread by mosquitoes or sexual contact. About 4 in 5 people who have the infection have no symptoms. Those who do get symptoms might have fever, rash, tiredness, aches and pains. Zika virus infections in Australia are generally reported in people who have travelled to a country where the virus is very common, such as in Central and South America and the Pacific. Zika virus is not found in Australia.

The Australian Department of Health recommends that women who are pregnant or trying to become pregnant should avoid travel to a country affected by Zika because there are concerns that pregnant women infected with the Zika virus might pass the infection on to their unborn babies, causing health problems for the baby, including microcephaly. If you need to travel to one of these countries, you should follow recommendations on preventing mosquito bites, and it is also recommended that pregnant women who have returned from a location where Zika virus is common are tested for the infection.

Because the Zika virus can be passed along by sexual contact, men who travel to places where Zika is common should avoid unprotected sex for 8 weeks after returning, and longer if their partner is planning a pregnancy.

If you have any questions about microcephaly or the Zika virus, talk to your doctor.