What is Chickenpox?

Chickenpox is a common childhood infection to which 5-10% of adults are susceptible. Most adults have already been exposed as children and are therefore immune to another infection. It is usually more severe as an adult. Pregnancy occurrences are rare–only 1 in 1000 with a 3% incidence of congenital anomalies if chicken pox occurs during pregnancy. The virus gains its entry via conjunctivae (eye secretions), open sores, and the respiratory tract. The virus does not survive in scabs or crusts.

Incubation Period

10-12 days– symptoms during this time are mild fever and fatigue. Up to 14 days after the mild fever and fatigue a rash appears with sores. New lesions can appear up to 5 days from the first lesion.

Newborn Risk

During pregnancy, the highest risk is between 1 week before delivery and 2 days after delivery. During pregnancy a woman with chickenpox can transfer her new immunity to the newborn after 5 days.

How Does Chickenpox Begin?

Fever and fatigue 24 hours before the rash. Rash usually begins on the face, mucus membranes, neck and trunk. Lesions crust over and heal in about 3 weeks. The cycle of lesions follows this pattern: reddened area–raised area– lesions with fluid–scabs.

What Can Happen To A Fetus That Gets Sick?

  • Disturbances in the nervous system
  • Small limbs, scapula, clavicle and ribs
  • Cataracts
  • Muscular weakening
  • Small eyeballs
  • Ultrasound Findings of Affected Fetus
  • Extra amniotic fluid around fetus
  • Slow movement
  • Flexed limbs


If you have never had chickenpox, a blood test can determine your immunity. Some adults are immune even if they never clinically developed chickenpox. If exposed at term, an injection can be given to protect mom from complications of pneumonia. There is a little coverage to the baby. If delivery is greater than 1 week away the baby will gain the mother’s immunity.


Not given in pregnancy
Immunity to adults 80% of time after vaccine

Maternal Complication During Pregnancy

  • Pneumonia 1 in 400 cases
  • Heart Infections
  • Encephalitis
  • Motor and sensory loss

If you have a confirmed case of chickenpox during your pregnancy, we may ask you to see your primary care provider to avoid exposure to our pregnant patients. Once all the lesions are covered over you may return to our office.