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- What is prematurity?
A birth is considered premature if the baby is born less than 37 weeks from the time the mother had her last menstrual period (was conceived) to the time the baby was born. This range of time from conception to birth is called gestation. Prematurity means the baby was born:
* More than three weeks before a baby’s due date, or
* Before 8.5 months gestation
To be a full term birth, a baby is born between 37 and 40+ weeks gestation.
A baby is considered very premature if it is born less than 32 weeks from the time the mother had her last menstrual period to the time the baby was born.
More than a half million babies in the United States, or 1 in every 8 are born premature each year. The preterm birth rate has risen 13% between 1996 and 2006 (from 9.90% in 1996 to 11.2% in 2006) in Wisconsin.
- What is the relationship between prematurity and the environment?
Increases in risk of prematurity or preterm delivery have been related to exposures during pregnancy to tobacco smoke, air pollution, lead, and some solvents. Other environmental exposures impacting preterm birth remain uncertain.
- What are the health effects related to prematurity?
Prematurity is the leading cause of death among newborn babies. Being born premature is also a serious health risk for a baby. Some babies will require special care and spend weeks or months hospitalized. Those who survive may face lifelong problems such as:
* intellectual disabilities,
* cerebral palsy,
* breathing and respiratory problems,
* vision and hearing loss, and
* feeding and digestive problems.
Although the more preterm a baby is born, the more severe his or her health problems are likely to be, even babies born just a few weeks early can have more health problems than full-term babies. For example, a baby born at 35 weeks is more likely to have jaundice, breathing problems, and longer hospital stays than a full term baby.
- What are the risk factors for premature birth?
Although nothing can guarantee that a person will not have a premature baby, there are some risk factors that may increase the chances a baby will be born premature.
* Carrying more than one baby (twins, triplets, quadruplets or more).
* Having a previous preterm birth.
* Problems with the uterus or cervix.
* Chronic health problems in the mother, such as high blood pressure, diabetes, and clotting disorders.
* Certain infections during pregnancy.
* Cigarette smoking, alcohol use, or illicit drug use during pregnancy.
There are additional lifestyle and environmental risk factors that have been linked to prematurity but the scientific evidence supporting these links are unclear. They include:
* Late or no prenatal care,
* Domestic violence,
* Lack of social support,
* Long working hours with long periods of standing,
* Being underweight before pregnancy,
* Marital status,
* Spacing of births (less than 6-9 months between birth and the beginning of the next pregnancy),
* Neighborhood-level characteristics
* Exposure to environmental chemicals such as air pollutants and drinking water contaminated with hazardous chemicals such as disinfection by-products or lead.
- Why do premature measures only include singleton births?
Singleton births are births where only one child is born versus multiple or plural births that are commonly referred to twins or triplets. Only singleton births are included in the measures described here in order to isolate the reproductive outcomes associated with environmental exposures, rather than due to changes in social or technological advances over time that have changed the rate of multiple births. The rise in multiple and plural births is most likely the result of increased reproductive technologies, such as fertility drugs, and not due to changing levels of environmental contaminants. Also, multiple/plural births are much more likely than singletons to be preterm. It is our intent to assess changes in prematurity in singleton births in order to avoid confusion with causes of prematurity in births of multiples. The premature measures using single births are:
* Percent of preterm births among singleton live born infants
* Incidence of preterm births among singleton live born infants
* Incidence of very low birth weight births among singleton born births
- What can I do to avoid having a premature baby?
Preterm birth can happen to anyone and many women who have a premature birth have no known risk factors. These are things you can do to improve your own health and lower your risk of having a premature baby:
* Quit smoking and avoid substances such as alcohol or drugs.
* If you plan to become pregnant, then see your health care provider for a medical checkup.
* Work with your health care provider to control diseases such as high blood pressure or diabetes.
* Get prenatal care early, as soon as you think you may be pregnant, and throughout the pregnancy.
* Discuss concerns during pregnancy with your health care provider, and seek medical attention for any warning signs or symptoms of preterm labor.
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Last Revised: March 26, 2012
Data QuerySingleton Premature Birth
Singleton Very Premature Birth
Access the premature birth data in the WI EPHT online database.
The WI EPHT online database has data about other reproductive outcomes. Review the Data Details below to learn about interpreting the data.
- Birth Rate
- Fertility and Infertility
- Infant Mortality
- Low Birth Weight
- Sex Ratio
What is the data source?
The website provides data from the statistical resident birth and death files, maintained by the Wisconsin Vital Statistics Records Office, Wisconsin Department of Health Services. This office also provides reproductive outcomes data on the Wisconsin Interactive Statistics on Health.
How does WI EPHT measure reproductive outcomes?
The WI EPHT website includes the following measures:
- Annual percent of low birth weight babies by state by gender by age by race
- Annual percent of premature babies by state by gender by age by race
- Annual percent of singleton low birth weight babies by state by gender by age by race
- Annual percent of singleton premature babies by state by gender by age by race
- Annual birth rate per 1000 babies by state by gender by age by race
- Annual infant mortality rate per 1000 babies by state by gender by age by race
- Annual singleton birth count by state by gender by age by race
- Annual singleton birth rate per 1000 babies by state by gender by age by race
- Annual total birth count by state by gender by age by race
- Annual percent of low birth weight babies by county
- Annual percent of premature babies by county
- Annual percent of singleton low birth weight babies by county
- Annual percent of singleton premature babies by county
- Annual birth rate per 1000 babies by county
- Annual singleton birth count by county
- Annual singleton birth rate per 1000 babies by county
- Annual total birth count by county
What are some considerations for interpreting the data?
While significant effort is made to ensure the accuracy and completeness of the data, there are limitations that are listed below:
- There are cooperative exchange procedures in place to help ensure data are included for Wisconsin residents born in other states, but it is possible not all other states have provided complete information at the time this report was created. The numbers are likely quite small, and thus the incompleteness probably has limited impact on the measures provided from the EPHT program.
- The measures are based on responses recorded on the birth certificate. There is not separate reporting specific to these reproductive outcomes.
There are many factors that can contribute to a disease and should be considered when interpreting the data. Some of these include:
- Demographics, e.g., race, gender, age
- Socioeconomic Status, e.g., income level, education
- Geographic, e.g., urban vs. rural
- Changes in the medical field, e.g., diagnosis patterns, reporting requirements
- Individual behavior, e.g., diet, smoking