Environmental Public Health Tracking - Birth Defects

A birth defect is an abnormality of structure, function, or metabolism (body chemistry) present at birth that results in physical or mental disabilities or, sometimes, even death.

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Birth Defects

In the United States, about 3% or one out of every 33 babies is born with a birth defect. Most birth defects are thought to be caused by a complex mix of genetic, behavioral, and environmental factors, although for many birth defects, exactly how these factors work together is unclear.

The causes of between 70 and 80 percent of birth defects are unknown. Sometimes they just happen with no clear cause. Sometimes the cause of a birth defect is determined after the baby is born.

It is not clear how many birth defects are related to environmental exposures, such as chemicals, ionizing radiation, drugs, and infections. Researchers are looking at a wide variety of environmental exposures and risk factors as possible causes.

Birth defects data reported on this website are obtained from the Massachusetts Center for Birth Defects Research and Prevention within the Massachusetts Department of Public Health/Bureau of Family Health and Nutrition. This center collects birth defects data from birthing hospitals and other medical facilities throughout Massachusetts.

Twelve birth defects are included on the EPHT network. They include: anencephaly, spina bifida (without anencephaly), hypoplastic left heart syndrome, tetralogy of Fallot, transposition of the great arteries (vessels), cleft lip with cleft palate, cleft lip without cleft palate, cleft palate without cleft lip, hypospadias, gastroschisis, limb deficiencies, and trisomy 21. Definitions of these birth defects can be found in the Birth Defect Descriptions tab and glossary.

Available Data on Birth Defects

Use the Explore Maps & Tables link on this page to access the following measures for birth defects in your community. The most current available data will be shown. Be sure to check the site periodically as new data are added each year. To protect privacy, no information is shown that could identify an individual.

  • Annual state birth defects prevalence per 10,000 live births by birth defect
  • 5-year birth defects prevalence per 10,000 live births for Massachusetts counties and statewide by birth defect

Birth Defect Descriptions

Anencephaly

Anencephaly is a birth defect that affects the closing of the neural tube during pregnancy. The neural tube is a narrow channel that folds and closes during the third and fourth weeks of pregnancy to form the brain and spinal cord. Anencephaly occurs when the part of the neural tube that forms the brain does not close. This results in the baby lacking parts of the brain, skull, and scalp.

Cleft Lip

A cleft lip is a congenital defect of the upper lip in which there is incomplete closure. The opening in the lip can be a small slit in the lip or a large opening that goes through the lip into the nose.

Cleft Palate

A cleft palate is an opening in the roof of the mouth, called the palate. A cleft palate can occur when the two sides of the palate do not come together correctly.

Gastroschisis

A birth defect in which a portion of an infant’s intestines stick out of the body through a small hole in the body wall beside the umbilical cord. The body wall defect can be small or large and other organs such as the liver can be involved.

Hypoplastic Left Heart Syndrome

A type of congenital heart defect that affects normal blood flow through the heart. Several parts of the left side of the heart do not fully develop.

Hypospadias

A birth defect among boys in which the opening of the urethra is located somewhere along the underside of the penis instead of at the tip. The urethra is the tube that carries urine from the bladder to the outside of the body. This defect occurs when the urethra does not complete its development during the pregnancy.

Limb Deficiency

Upper limb deficiency defects occur when a part of or the entire arm (upper limb) of a fetus fails to form completely during pregnancy. Lower limb deficiency defects occur when a part of or the entire leg (lower limb) of a fetus fails to form completely during pregnancy.

Spina Bifida (without Anencephaly)

The neural tube is a narrow channel that folds and closes during the third and fourth weeks of pregnancy to form the brain and spinal cord. Spina bifida is a neural tube defect that happens if part of the neural tube does not close all the way.

Tetralogy of Fallot

A type of congenital heart defect that changes the normal flow of blood through the heart. Tetralogy of Fallot is a combination of four defects: (1) a hole in the wall between the ventricles (two lower chambers of the heart), called a ventricular septal defect; (2) narrowing of the tube that carries blood from the heart to the lungs, called pulmonary stenosis; (3) the aorta (the tube that carries oxygen-rich blood to the body) grows from both ventricles, rather than from the left ventricle only; and (4) a thickened muscular wall of the right ventricle, called right ventricular hypertrophy.

Transposition of the Great Arteries

A type of congenital heart defect that occurs when the two main arteries going out of the heart—the pulmonary artery and the aorta—are switched in position, or “transposed.”

Trisomy 21 (Down Syndrome)

Down syndrome is a condition in which a baby is born with an extra chromosome, chromosome 21. This extra copy changes the normal development of the body and brain and can cause developmental and physical problems for the baby.

Source: CDC Birth Defects Home Page, 2015

Birth Defect TypeDescription
AnencephalyAnencephaly is a birth defect that affects the closing of the neural tube during pregnancy. The neural tube is a narrow channel that folds and closes during the third and fourth weeks of pregnancy to form the brain and spinal cord. Anencephaly occurs when the part of the neural tube that forms the brain does not close. This results in the baby lacking parts of the brain, skull, and scalp.
Cleft LipA cleft lip is a congenital defect of the upper lip in which there is incomplete closure. The opening in the lip can be a small slit in the lip or a large opening that goes through the lip into the nose.
Cleft PalateA cleft palate is an opening in the roof of the mouth, called the palate. A cleft palate can occur when the two sides of the palate do not come together correctly.
GastroschisisA birth defect in which a portion of an infant’s intestines stick out of the body through a small hole in the body wall beside the umbilical cord. The body wall defect can be small or large and other organs such as the liver can be involved.

Related Links

National Sources

Massachusetts Sources

Frequently Asked Questions

What is birth defects tracking?

Birth defects tracking, or surveillance, is the ongoing collection, analysis, and interpretation of birth defects data in a population of children from birth up to age one.  Massachusetts law requires the reporting of birth defects to the Massachusetts Department of Public Health (MDPH). The Massachusetts Center for Birth Defects Research and Prevention was established in 1996 within MDPH as an active state-wide, population-based birth defects registry. The EPHT portal allows users to review both birth defects data and environmental data to help determine the need for follow-up investigations.

Why is the EPHT Program tracking birth defects?

In 2002, Massachusetts was one of seven states across the U.S. to be awarded funds from the U.S. Centers for Disease Control and Prevention (CDC) to track health conditions thought to be impacted by the environment.  By sharing data about the occurrence of birth defects in Massachusetts, the EPHT Program hopes to better understand the potential for environmental factors to play a role.

How is information collected on birth defects in Massachusetts?

The Massachusetts Birth Defects Monitoring Program (MBDMP) is an active, statewide surveillance program.  It is part of the Massachusetts Center for Birth Defects Research and Prevention within the Massachusetts Department of Public Health/Bureau of Family Health and Nutrition. Birthing hospitals and other pediatric care centers across the state regularly submit birth defect diagnoses to the Center. These diagnoses are verified through medical record abstraction conducted by Center staff; during the abstracting process additional important demographic information is collected. Also, vital records, including birth certificates, fetal death reports, and infant death certificates are reviewed for qualifying diagnoses. The diagnoses are reviewed by a clinical geneticist and entered into a secure confidential electronic database maintained by the MBDMP.

If my child was born with a birth defect, will information on my child or family be available to the public?

No.  Only summary statistics on the occurrence of birth defects in Massachusetts will be available through the EPHT network.  No personally-identifying information on your child or your family will ever be disclosed. Extensive procedures are in place to guarantee the confidentiality of the birth defects data and to protect the privacy of families. These procedures uphold MDPH ethical and legal obligations to safeguard confidentiality and they fully comply with the strict requirements of state and federal laws.

What statistic is used to measure the number of birth defects in a county or the state of Massachusetts as a whole?

The occurrence of birth defects in an area is estimated by calculating a statistic called prevalence. Prevalence is defined generally as the number of individuals with a disease or condition over a specified period of time divided by the number of individuals at risk during the same period. For birth defects, prevalence is defined as the number of infants less than one year of age with a birth defect divided by the number of live births over a specified period of time, typically over a one-year period. 

Prevalence is usually expressed as the number of birth defect births per 10,000 live births.  It is calculated using the formula:

(number of infants with birth defect(s) / total number of live births) * 10,000

The number of live births in the denominator of the prevalence estimate is an approximation of the number of total pregnancies during the time period of interest.  Because the number of pregnancies cannot be determined, the number of total births is used as an approximation.

How are prevalence estimates interpreted?

To best interpret the prevalence estimate for a county or the state a statistic referred to as a confidence interval (CI) is used.  Confidence intervals are commonly used to assess the magnitude and stability of disease rates or, in this case, the prevalence of birth defects. The CI can also help determine if the prevalence estimate for a county is statistically significantly different from the statewide experience for that birth defect. That is, does the difference between the two prevalence estimates most likely represent normal random variation in prevalence estimates or is it a statistically significant difference?

The CI represents a range of values that has a 95% probability of including the true prevalence. The width of the confidence interval reflects the size of the population and the number of birth defects. The prevalence estimate for a smaller population with fewer birth defects, such as that of a more sparsely populated county in the state, will lead to a wider confidence interval.  In contrast, the confidence interval for the prevalence of a birth defect for the state as a whole will be narrower. 

As mentioned, one method for determining if a given prevalence estimate is statistically significantly different from another is to compare their confidence intervals. The prevalence of birth defects in a county can be compared to the prevalence of birth defects in the state as a whole using the two CIs.  If the CI for one county does not overlap the CI of the state, then it can be concluded that the prevalence estimates are statistically significantly different from each other.  If they do overlap, then it can be concluded that the birth defect prevalence estimates are not likely to be statistically significantly different. 

What is the relationship between birth defects and the environment?

Some research on environmental hazards and associations with birth defects is available; however, much more work is needed to more fully understand the relationship between the environment and birth defects.

Environmental substances that can cause birth defects are called teratogens. These include alcohol, certain drugs/medications, infections and certain chemicals.

Some endocrine-disrupting chemicals, including polychlorinated biphenyls (PCBs), dioxins, and pesticides, have been linked to nervous system defects and developmental problems such as reduced muscle tone and response.

The CDC has reported that living near a hazardous waste site has been identified as a possible risk factor for birth defects such as neural tube defects. Neural tube defects are defects in the development of the brain and spinal cord. Exposure to disinfection by-products in drinking water such as trihalomethanes, or THM, may increase the risk of some types of birth defects.

Most experts believe that the majority of birth defects are likely to be the result of a complex interaction between genetic predisposition and environmental factors.

Are there other known risk factors for birth defects?

Some birth defects are caused by genetic problems. Sometimes, these birth defects run in families, but other times they will occur even when there is no one else in the family who has this problem.

If a woman takes certain drugs during her pregnancy, the chance of birth defects in her offspring is increased. Also, women who smoke and use alcohol while pregnant have a higher risk of having a baby with certain birth defects.

Folic acid (vitamin B9) deficiency is related to certain birth defects.  Studies have shown that the presence of adequate amounts of folic acid in the mother’s system during the period around conception may help prevent defects of the brain and spinal cord. 

Women over the age of 35 years have a higher chance of having a child with Down syndrome than women who are younger.  Teenage mothers are more likely to have a baby born with gastroschisis —a defect in the abdominal wall.

It is important to note, however, that the Massachusetts Center for Birth Defects Research and Prevention estimates that approximately 80% of birth defects in the state have unknown causes.

What are the limitations of the data?

  • Defects related to early fetal deaths and/or terminations are not included in prevalence estimates. Furthermore, defects that are not diagnosed at birth, do not need hospitalization, or are diagnosed after age one may be underreported.
  • There is the possibility of misclassification due to a vague or miscoded diagnosis which may affect birth defect prevalence measures. Quality control measures such as careful medical record abstraction minimize this error.
  • It is important to note that prevalence estimates are based on the residential location of the mother at the time of the child’s diagnosis.
  • Counts and prevalence estimates may differ slightly from those contained in other publications. These differences may be due to file updates, differences in calculation methods (such as grouping ages differently or rounding off numbers at different points in calculations), updates or differences in population estimates, and differences in birth defects definitions.
  • Only diagnoses confirmed before one year of age are included.

What types of birth defects are included on the EPHT network?

Twelve birth defects are included on the EPHT network. They include: anencephaly, spina bifida (without anencephaly), hypoplastic left heart syndrome, tetralogy of Fallot, transposition of the great arteries (vessels), cleft lip with cleft palate, cleft lip without cleft palate, cleft palate without cleft lip, hypospadias, gastroschisis, limb deficiencies, and trisomy 21. Definitions of these birth defects can be found in the glossary.

What are the Codes and Exclusions for each birth defect category?

The following coding schme is derived from the National Birth Defects Prevention Network (NBDPN) Case Definitions, revised 2015.
Birth Defect ICD-9-CM1 CDC/BPA2 ICD-10-CM3
Anencephaly 740.0-740.1 740.00-740.10 Q00.0 - Q00.1
Cleft Lip with Cleft Palate 749.2 749.20-749.29 Q37.0-Q37.9
Cleft Lip without Cleft Palate 749.1 749.10-749.19 Q36.0-Q36.9
Cleft Palate without Cleft Lip 749.0 749.00-749.09 Q35.1 – Q35.9
Gastroschisis (prior to 10/01/2009) 756.79 (This is a shared code with omphalocele. If your state uses ICD-9 codes, please indicate in your metadata if you have another method to distinguish these two conditions.  If not, you do not have to report the data.) 756.71 NA
Gastroschisis (starting on 10/01/2009) 756.73 756.71 Q79.3
Hypoplastic Left Heart Syndrome 746.7 746.7 Q23.4
Hypospadias 752.61 752.60 – 752.62 (excluding 752.61 and 752.621) Q54.0 – Q54.9 (excluding Q54.4)
Limb Deficiencies 755.2 – 755.4 755.20 – 755.49 Q71.0 – Q71.9, Q72.0 – Q72.9, Q73.0 – Q73.8
Spina Bifida (w/out anencephaly) 741.0, 741.9 without 740.0-740.10 741.00-741.99 without 740.0-740.10 Q05.0 - Q05.9, Q07.01, Q07.03 without Q00.0 - Q00.1
Tetralogy of Fallot 745.2 745.20 – 745.21, 747.31 Q21.3
Transposition of the Great Arteries 745.10, 745.12, 745.19 (Note: for CCHD, 745.10 only (d-TGA only)) 745.10 – 745.12, 745.18 – 745.19 (Note: for CCHD, 745.10 (TGA complete, no VSD), 745.11 (TGA incomplete, with VSD), 745.18 (other specified TGA), 745.19 (unspecified TGA) Q20.3, Q20.5 (Note: for CCHD, Q20.3 only)
Trisomy 21 758.0 758.00-758.09 Q90.0 – Q90.9

1International Classification of Diseases, 9th Revision, Clinical Modification

2Centers for Disease Control/ British Pediatric Association

3International Classification of Diseases, 10th Revision, Clinical Modification

      
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1 in 33  Babies in the United States are born each year with birth defects.
About 120,000 babies (1 in 33) in the United States are born each year with birth defects.

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