Complications of chickenpox during pregnancy

Pregnant women who have chickenpox are at risk of complications. The type of complications depend on when the infection developed during pregnancy.

• Pregnant women who have chickenpox during the first half of pregnancy may go into labor early (premature labor) or have a miscarriage.
• Pregnant women who have chickenpox in the last part of pregnancy are more likely to develop varicella pneumonia. Even a healthy pregnant woman is at risk of dying if she develops varicella pneumonia.
• About 2% to 3% of fetuses whose mothers have chickenpox during the first 20 weeks of pregnancy will also develop chickenpox.¹ This is called congenital varicella and can cause:
  • Birth defects. Birth defects can include one limb (usually a leg) smaller than the other, scars on the limbs, or eye problems such as cloudy lenses.
  • Low birth weight (weigh less than expected at birth).
  • Seizures. The baby can have seizures after birth.
  • Mental retardation.
  • Shingles. Fetuses who have chickenpox will not have chickenpox again. However, they can still have shingles, even as babies or young children.
  • Death. About 50% of those fetuses who develop congenital varicella die.¹
• Newborn babies are likely to develop chickenpox within 5 to 10 days after birth when the mother had the illness a few days before or during delivery. These babies are at greater risk of complications from chickenpox.