Chickenpox or Varicella is a very infectious illness caused by a virus called herpes zoster. Most people get chickenpox in childhood, when it is a mild infection causing a rash. Once you have had chickenpox, you cannot catch it a second time.

The symptoms of chickenpox  usually appear between 10 days to 3 weeks. This includes:

  • Fever and feeling unwell
  • Formation of watery blisters, anywhere over the body

You can be infected from someone who currently has it. A person is contagious from 2 days before the rash appears to when all the blisters have crusted over. During this time, you can catch chickenpox by being:

  • in close contact with them
  • face to face with them for at least 5 minutes
  • in the same room with them for at least 15 minutes.

The chickenpox can be prevented effectively via vaccination. The vaccination cannot be given during pregnancy and one should avoid getting pregnant for 3 months after the injection.

What to do if a pregnant woman come into contact with chickenpox?

The pregnant woman is “protected” if she had chickenpox before. However, she has never been exposed to chickenpox before, or develop a rash in pregnancy, or are not sure, see your doctor immediately.

If the pregnant woman is not immunized/protected against chickenpox, she may be given an injection of varicella zoster immune globulin (VZIG). This can make the infection milder and not last for as long. The injection can be given for up to 10 days after you come into contact with chickenpox and before any of your symptoms appear. VZIG does not work once you have blisters.

The effect of chickenpox on pregnancy

Only a very small number of women (3 in every 1000 or 0.3%) catch chickenpox in pregnancy. Even fewer babies are affected in the uterus.

If chickenpox occur prior to 28 weeks of pregnancy
There is no evidence that you are at an increased risk of early miscarriage because of chickenpox. Damage can occur to the eyes, legs, arms, brain, bladder or bowel in 1-2 of every 100 babies (1-2%).

Meanwhile if infection occurs between 28 and 36 weeks of pregnancy
The virus stays in the baby’s body but will not cause any symptoms. The virus may become active again causing shingles in the first few years of the child’s life.

Infection after 36weeks and to birth, the baby may become infected and could be born with chickenpox. If the baby is born within 7 days of your chickenpox rash appearing, the baby may get severe chickenpox. The baby will need treatment.


Author: Dr Ng Soon Pheng

Dr. Ng Soon Pheng MD(USM), M.Med (O&G), Fellow Reprod Medicine (Singapore), AM (Mal) Dr. Ng Soon Pheng qualified from University Kebangsaan Malaysia (UKM), Malaysia. After obtaining his post graduate degree, Dr. Ng Soon Pheng continued his clinical fellowship training in the field of IVF in Singapore. He was also the recipient of Yayasan Sultan Iskandar (Johor) Scholarship for the fellowship stint. Dr. Ng Soon Pheng has more than 10 years of working experience in the field of Obstetrics and Gynaecology in the public and university hospital, with special interests in infertility. He was an Associate Professor with the Department of O&G in Universiti Kebangsaan Malaysia (UKM) specialising in infertility. Dr. Ng Soon Pheng is currently Consultant Obstetrician and Gynaecologist with special interests in infertility at Columbia Asia Hospital - Puchong.