Congenital Zika syndrome

KEY POINTS

  • Congenital Zika syndrome is a group of health conditions present at birth associated with Zika infection during pregnancy.

  • Congenital Zika syndrome includes birth defects (like microcephaly) and other health and development problems.

  • Babies with congenital Zika syndrome need special medical care from a team of health care providers and other specialists.

  • The best way to protect your baby from congenital Zika syndrome is to protect yourself from Zika infection before and during pregnancy.

What is congenital Zika syndrome?

Congenital Zika syndrome is a group of health conditions present at birth associated with Zika infection during pregnancy. Zika is a virus. If you get infected with Zika during pregnancy, the virus can pass through the placenta to your baby. The placenta grows in your uterus (womb) and supplies your baby with food and oxygen through the umbilical cord. 

If the Zika virus reaches your baby’s brain, it can slow brain growth and kill brain cells, and some parts of the brain may not develop. Problems in the brain that are part of congenital Zika syndrome include: 

  • Microcephaly. This is a birth defect in which a baby’s head is smaller than expected, compared to babies of the same sex and age. A birth defect is a health condition that is present at birth. Birth defects change the shape or function of one or more parts of the body. They can cause problems in overall health, in how the body develops or in how the body works. Babies with mild microcephaly often don’t have problems other than small head size. A baby with severe microcephaly has a head that’s much smaller than expected and may have more serious health problems than babies with mild microcephaly.
  • Calcium deposits. Calcium can build up in your baby’s brain tissue and affect the way your baby’s brain works. 
  • Enlarged ventricles and hydrocephalus. Ventricles are spaces in the brain that fill with fluid. When fluid builds up, it causes pressure on the brain. This is called hydrocephalus. 
  • Fetal brain disruption sequence. Babies with fetal brain disruption sequence may have severe microcephaly, problems with the skull (including collapsed skull or skull bones that overlap), extra skin on the scalp and problems with the nervous system. 
  • Smooth brain. A healthy brain has many folds and grooves in it. For some babies, the brain may be smooth with no folds or few folds. Some babies with this condition don’t have serious health problems, but others stop developing after 3 to 5 months and many die before they are 2.

Other health conditions that are part of congenital Zika syndrome include:

  • Low birthweight. This is when a baby is born weighing less than 5 pounds, 8 ounces. 
  • Growth and development problems, including trouble swallowing, problems with balance and movement, and intellectual and developmental disabilities. These are problems with how the brain works that can cause a person to have trouble or delays in physical development, learning, communicating, taking care of himself or getting along with others.
  • Hearing loss and other hearing problems. Hearing loss is when you can’t hear sound in one or both ears. 
  • Nervous system problems, including hypertonia, hypotonia, seizures and severe fussiness. The nervous systems is made up of your brain, spinal cord and nerves. Your nervous system helps you move, think and feel. Hypertonia is when a baby has too much muscle tone. A baby with hypertonia may have stiff hands or legs that are hard to move. Hypotonia is when a baby has too little muscle tone. A baby with hypotonia may seem floppy and have poor head control (the head falls forward, backward or to the side). A seizure is when the whole body or parts of the body move without control.
  • Problems with limbs or joints, including birth defects like arthrogryposis, clubfoot and congenital hip dysplasia. A joint is a part of the body where two or more bones come together, like the knee, hip, elbow or shoulder. A baby with arthrogryposis is born with joint problems that make it hard for her to move her hands or legs. Her joints may not move the right way or they may get stuck in one position. If a baby has clubfoot, one foot or both feet point down and turn in. Babies with clubfoot also may have abnormal foot bones, ankle joints and muscles. Babies born with hip dysplasia have an abnormal hip joint where the top of a hip bone doesn't stay firmly in the hip socket.
  • Vision problems. These include damage to the retina and torpedo maculopathy. The retina is the nerve tissue that lines the back of the eye. Torpedo maculopathy is when your baby has an oval-shaped scar (also called a lesion) in the central part of the retina.

How can you prevent congenital Zika syndrome in your baby?

You can prevent congenital Zika syndrome in your baby by not getting infected with Zika before or during pregnancy. The Zika virus is spread mostly through infected mosquitoes. You also can get it by having unprotected sex with an infected person or by coming into contact with infected body fluids, like through a blood transfusion or if you work in a health care setting. Learn how to protect yourself from Zika infection to prevent congenital Zika syndrome in your baby. 

How do you know if your baby has congenital Zika syndrome?

Not all babies are checked for congenital Zika syndrome after birth. Your baby gets tested for Zika infection and health conditions that are part of congenital Zika syndrome if:

  • You tested positive for Zika infection during pregnancy. 
  • You may have been exposed to Zika during pregnancy and your baby has health or development problems after birth like those that are part of congenital Zika syndrome.

Your baby’s health care provider uses these tests to check for Zika infection and for health conditions that are part of congenital Zika syndrome:

  • A blood and urine test for Zika. Your baby gets tested within 2 days of birth. If your baby’s spinal fluid is being tested, it also may be tested for Zika.
  • A detailed physical exam to check your baby’s head size, weight and length
  • Ultrasound of the head to check your baby’s skull and brain. An ultrasound uses sound waves and a computer screen to show a picture of the inside of the body.
  • Tests to check for problems with your baby’s nervous system 
  • Hearing test as part of newborn screening. Your baby gets newborn screening before he leaves the hospital after birth. Newborn screening checks for serious but rare conditions that your baby has at birth. It includes blood, hearing and heart screening.

Does your baby need special medical care if he has Zika or congenital Zika syndrome?

Yes. A team of health care providers and other specialists help care for your baby. Your baby’s care depends on his condition at birth: 

  • If your baby has or may have Zika and has health conditions that are part of congenital Zika syndrome, he needs special medical care. A team of health care providers closely monitors your baby’s health, growth and development. They check your baby’s nervous system, vision, hearing and hormones (chemicals made by the body). Your baby gets a complete eye exam and a hearing test called auditory brainstem response (also called ABR) before he’s 1 month old. This test uses patches (also called electrodes) and a computer to check how your baby reacts to sound. Your baby needs extra medical checkups and tests for at least 6 months after birth. 
  • If your baby has or may have Zika but doesn’t have health conditions that are part of congenital Zika syndrome, he gets a complete eye exam and an ABR test before he’s 1 month old. Your baby gets routine well-baby checkups, and his provider closely checks his growth and development during his first year of life. Your baby may need a repeat ABR test at 4 to 6 months.
  • If your baby doesn’t have Zika but has health conditions that are part of congenital Zika syndrome, his provider checks for other conditions that may be causing your baby’s health problems. For example, being exposed to other infections in the womb may cause microcephaly. These infections include chicken pox (also called varicella), rubella (also called German measles), toxoplasmosis and cytomegalovirus.  

Experts think some babies exposed to Zika during pregnancy may appear healthy at birth, but they may have health or development problems later. This is why it’s so important to take your baby to all his medical checkups and to tell his provider if you’re worried about his health and development. 

Do babies with congenital Zika syndrome need early intervention services?

Yes. If your baby has developmental delays, it’s important to get early intervention services as soon as possible. Developmental delays are when your child doesn't reach developmental milestones when expected. A developmental milestone is a skill or activity that most children can do at a certain age. Milestones include sitting, walking, talking, having social skills and having thinking skills. 

Early intervention services can help improve your child’s development. They can help children from birth through 3 years old learn important skills. Services include therapy to help a child talk, walk, learn self-help skills and interact with others. Visit the Early Childhood Technical Assistance Center to find your state’s contact information for early intervention services.

If your baby has congenital Zika syndrome, is it OK to breastfeed?

Yes. Breast milk is the best food for most babies for the first year of life. 

If your baby has problems swallowing or feeding, her provider may refer you to a lactation consultant for help. Even if your baby breastfeeds well after birth in the hospital, she may have feeding problems after you’re home. A lactation consultant has special training to help women breastfeed. If you’re worried about your baby’s feeding, tell her provider.

Last reviewed: November, 2016