Environmental Public Health Tracking: Birth Defects Data

A birth defect is a problem that happens while the baby is developing before birth. Most birth defects happen during the first three months of pregnancy.

A birth defect may affect how the body looks, works, or both. It can be found before birth, at birth, or any time after birth. Most defects are found within the first year of life. Some birth defects, such as cleft lip or clubfoot, are easy to see. Other birth defects, such as heart defects and hearing loss, are found using special tests, such as x-rays, CAT scans, or hearing tests. Birth defects can vary from mild to severe.

Some birth defects can cause the baby to die. Babies with birth defects may need surgery or other medical treatments. However, if babies receive the help they need, they often lead full lives.

We receive data from the Wisconsin Birth Defects Registry. The Registry collects data for birth defects found in children from birth to 2 years of age. The reported birth defects were diagnosed or treated in Wisconsin by a physician, pediatric specialty clinic, or hospital. The defect must require medical or surgical intervention or interfere with normal growth and development. The Registry collects data for 87 reportable defects, and we selected 10 to track.

The 10 were selected for the following reasons:

• These defects are included as part of the annual report for the NPDPN.
• Concerns from the public indicate a belief that these defects might be related to environmental exposures.
• These defects are quite severe.
• Given the physical nature of many of the defects, it is likely there will be consistent diagnoses, which makes the data more reliable and useful.

We track the following 10 birth defects:

• Anencephaly
• Cleft Lip with or without Cleft Palate
• Down Syndrome (Trisomy 21)
• Gastroschisis
• Hypoplastic left heart syndrome
• Hypospadias
• Spina bifida (without anencephaly)
• Tetralogy of Fallot
• Transposition of the great arteries
• Upper and lower limb deficiencies

To understand Wisconsin's birth defects data, it's important to know that our data collection method has changed. This is because the Wisconsin Birth Defects Registry began collecting data on birth defects in 2004, and the registry was an opt-in system, meaning birth defect reporters (such as physicians) had to get parental consent to report a birth defect. As a result, the registry only caught some of the birth defects in Wisconsin. In September 2017, legislation changed the Wisconsin Birth Defects Registry from an opt-in system to an opt-out system. This means that since the fall of 2017, birth defect reporters add all defects to the registry unless a parent asks them not to do so. This change should be considered when analyzing these data.

About one in every 33 babies is born with a birth defect.¹ Every four and a half minutes, a baby is born with a birth defect in the United States.² In Wisconsin, nearly 2,000 babies are born with a birth defect each year.

Some people have a higher chance of having a child with a birth defect. Parents over the age of 35 years have a higher chance of having a child with Down Syndrome than parents who are younger.

If taken during pregnancy, certain drugs can increase the chance of birth defects. Also, smoking and using alcohol while pregnant increases the risk of having a baby with certain birth defects. A family's genetics can also increase the chances for a baby to have the same birth defect.

Parents can learn more about their risk of having a baby with a birth defect by talking with a genetics counselor. A health care provider can also help parents learn to reduce the risk of birth defects.

We do not know what causes most birth defects. Sometimes they just happen and are not caused by anything that the parents did or didn't do.

While we don’t always know what causes a birth defect, we do know some things increase the chances of a birth defect happening.

Birth defects happen before or during birth.

Most birth defects happen in the first three months of pregnancy, when the organs of the baby are forming.

This is the most important stage of development. However, some birth defects happen later in pregnancy. During the last six months of pregnancy, the tissues and organs continue to grow and develop.

A healthy pregnancy can help prevent birth defects, but not all birth defects can be prevented. Parents should talk to a health care provider when they are pregnant or planning to get pregnant. Care before birth can help avoid some problems and reduce the likelihood of birth defects.

To learn more about preventing birth defects, visit the CDC page on guidance for preventing birth defects.

Birth defects such as spina bifida, cleft lip/palate, gastroschisis, hypospadias, Down syndrome, and heart defects have all been linked to living near hazardous waste sites. Some birth defects have also been linked to disinfection by-products in drinking water.

The causes of most birth defects remain unknown. With the data we collect and the help of the CDC's National Tracking Program, researchers in the future will be better equipped to study the relationship between birth defects and the environment.

• Wisconsin Children and Youth with Special Health Care Needs Program
• CDC – Birth Defects
• Wisconsin Department of Health Services - Children and the Environment

Click the link below to download the data you're looking for:

Birth Defects Data (CSV)

Anencephaly

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Cleft lip without cleft palate

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Cleft lip with cleft palate

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Cleft palate without cleft lip

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Gastroschisis

Note: Prior to 10/1/2009, gastroschisis shared an ICD-9 code with omphalocele. Due to the inability to distinguish between those two conditions during that time, gastroschisis data is not available until 2010.

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Hypoplastic left heart syndrome

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Hypospadias

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 male live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Limb deficiencies combined

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Tetralogy of Fallot

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Transposition of the great arteries (vessels)

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.

Trisomy 21 (Down Syndrome)

Count

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. Cases were then summed over five year periods.

Crude rate per 10,000 live births

Data came from the NBDPN. NBDPN collects data from a combination of birth certificates, hospital discharge data and fetal death records. This is a five-year crude rate. Rates were calculated by dividing the count by the number of live births in Wisconsin in those years and multiplied by 10,000. Rates were suppressed if the count was three or less over a five year time period to avoid unstable rates. However, rates with zero cases are not suppressed.