Catching Contagious Diseases During Pregnancy

The good news is that you generally don’t have to worry too much about being exposed to most contagious childhood diseases during pregnancy, even though the risks of some to your unborn baby can be severe. That’s because it takes quite a lot of circumstances to come together for the risk to become reality.

Contagious childhood diseases are usually only a problem if they’re contracted in the first trimester, if you’ve never had them before (and therefore don’t have immunity against them), if you develop one of the quite rare secondary infections like meningitis or encephalitis, or if you develop an exceptionally high fever. Fortunately, your body has a number of safeguards in place to protect Baby, such as regulatory systems which keep your core temperature constant and help prevent Baby from overheating; and the placental barrier to ward off crossing of many microorganisms. Baby will also only be affected if the virus crosses the placenta, which doesn’t always happen. So, even if you contract one of these diseases, it’s not to say your baby will be affected!

Nonetheless, one should try and avoid exposure to children with these diseases if possible. Of course, it’s quite difficult to always avoid contact with infected people because often even they don’t realise they have the disease – the most contagious time for many childhood diseases is before the symptoms appear. In most cases you need to be in pretty close contact with droplet infection from coughing or sneezing in order to get infected. Many people become infected without realising it because they get flu-like symptoms which never develop into the full-blown disease – this may mean that you are immune to this disease without even knowing it. It’s best to minimise or avoid contact with anyone who has an infectious childhood disease just to be safe though.

Common childhood diseases

German measles

This is the most risky childhood disease if it’s contracted during the first trimester. Most women are tested for antibodies against German measles (rubella) in early pregnancy and are advised to stay away from small children if they don’t have any antibodies. It’s a good idea to do this test a few months before you fall pregnant so that you can be immunised and develop antibodies if you need to. If you have had  German measles and you’re pregnant, it is highly unlikely that your baby is at any risk.


Usually mumps isn’t a problem if it’s contracted during pregnancy – it runs the same course as usual. You can’t be immunised against mumps during pregnancy because it’s a ‘live’ vaccine.

Chicken pox

Roughly 90% of pregnant women have antibodies to the chicken pox virus, even if they don’t realise it – it may never have developed past the flu symptom stage! As is the case with most childhood diseases the symptoms are far worse when contracted as an adult – especially during pregnancy. In extreme cases chicken pox can cause skin lesions, smaller than normal limbs, eye defects, and mental retardation in Baby. This is very rare though and only 5% of women who don’t have the antibodies will contract the disease and have a baby with problems. Chicken pox is mostly a problem if it’s contracted in the first 12–16 weeks, although if it’s contracted a few days before delivery Baby will need intensive neonatal care. There is a chicken pox available for certain stages of pregnancy, but it’s still quite controversial.

Take-home message

Don’t worry unnecessarily about contracting childhood disease during pregnancy; simply keep your immune system as healthy as possible, make sure you are tested for antibodies to diseases like rubella, and see your doctor if you get flu-like symptoms.