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Skip Navigation LinksPennsylvania Department of Health > My Health > Environmental Health > Health Tracking Program > Reproductive Health Outcomes

reproductive HEALTH outcomes

Prematurity, Low Birth Weights, Infant Mortality,
Sex Ratio at Birth and Fertility

Premature Births
A premature or preterm birth occurs more than three weeks before a baby’s due date. Increases in
the risk of prematurity or preterm delivery have been related to exposures during pregnancy to air
pollution, lead and some solvents. 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 in a neonatal intensive care unit. 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. The earlier a baby is born, 
the more severe his or her health problems are likely to be. Not only is premature birth an emotional
roller coaster for families; there is a tremendous financial toll as well. Preterm births account for
health care expenditure of over three billion dollars per year. The average first year medical costs
were about 10 times greater for preterm than for full-term babies.
There are some known risk factors for premature birth.  Even if a woman does everything right during pregnancy, she can still have a premature baby. Some of the known risk factors are:
            -  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
            -  Certain infections during pregnancy
            -  Cigarette smoking, alcohol use, illicit drug use or even the use of some prescription
               medications during pregnancy 
            -  Mother’s age and race     
Other lifestyles and environmental factors include:
            -  Late or no prenatal care
            -  Domestic violence
            -  Lack of social support
            -  Stress
            -  Long working hours with long periods of standing
            -  Being underweight before pregnancy
            -  Obesity
            -  Marital status
            -  Spacing of births; less than six to nine months between birth and the beginning of the next  
            -  Neighborhood-level characteristics; disadvantages such as location, stability and poverty
            -  Environmental chemicals for example exposure to air pollution and drinking                water contaminated with  chemical  disinfection by-products or lead
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 at the same time:

Low Birth Weight/Growth Retardation
Early and continuous prenatal care helps identify conditions and behavior that can result in low birth

weight babies, such as smoking, drug and alcohol abuse, inadequate weight gain during pregnancy

and repeat pregnancy in six months or less. Infants born to teenage mothers are at higher risk of
being born low birth weight babies and have a higher mortality rate. There are some steps a woman
can take to reduce her risk of having a low-birth weight baby:
      -  Quit smoking and avoid substances such as alcohol or drugs.

      -  See your health care provider for a medical checkup before pregnancy.

      -  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  


      -  Discuss concerns during pregnancy with your health care provider, and seek medical attention

         for any warning signs or symptoms of preterm labor.

Infant and Perinatal Mortality
The fetus and young child may be particularly susceptible to harmful effects of environmental contaminants. Many environmental contaminants may be especially toxic in utero; many cross the placenta and make their way into the circulatory system of the developing fetus. Keep in mind that environmental exposure-related causes of infant and perinatal death are only one piece of a puzzle that includes many other factors such as access to and quality of health care, competency in childcare and understanding of injury prevention.
Outdoor air pollution is one example of a connection between environmental health and infant death. Air pollution in the form of particulate matter has been associated with a 10 percent increase in the rate of post-neonatal deaths.  These can occur from 28 days up through the first year of life. The major causes of death associated with air pollution are deaths from respiratory causes and sudden infant death syndrome or SIDS, also known as cot death or crib death. This is the sudden unexplained death of a child less than one year of age.
The leading causes of infant death include congenital abnormalities, pre-term/low birth weight, SIDS, problems related to complications of pregnancy, and respiratory distress syndrome. Infants born premature or low birth weight are more likely to die from SIDS. SIDS and death related to growth restriction are the leading causes of fetal loss. Fetal death is an important source of mortality,with the rate being many times higher than the rate of SIDS. Although the rate of late fetal loss (28+ weeks) has been decreasing in past decades, the rate of intermediate fetal loss (20-27 weeks) has remained relatively constant. Markers of increased risk for fetal loss include pre-pregnancy obesity, ethnicity, race and advanced maternal age. The leading causes of infant death include congenital abnormalities, pre-term/low birth weight, SIDS, problems related to complications of pregnancy, and respiratory distress syndrome. 
Health care providers should advise their patients about factors that affect birth outcomes, such as maternal smoking, drug and alcohol abuse, poor nutrition, stress, insufficient prenatal care, chronic illness and other medical problems. Communities and individuals can play an important role in this effort by encouraging pregnant women to seek prenatal care in the first trimester and educating providers, pregnant women and family members on factors that affect infant mortality. Parents and caregivers should always place sleeping infants on their backs. Research has demonstrated that babies who sleep on their stomachs or sides are at higher risk for SIDS. A separate sleeping environment, such as a crib in the parents’ bedroom, is sometimes recommended.

Fertility and Infertility
Approximately 10 percent of problems with fertility are caused by unknown and environmental

contaminants. Environmental contamination can have multi-generational impacts on reproduction

that need to be studied and tracked long term. Fertility is actual conception and birth, while fecundity
is the potential ability to bear a child and bring to term. Infertility occurs when a couple cannot get
pregnant after trying to conceive for one year, or six months over age 35.
It has been suspected that low-level exposures to a number of compounds, such as pesticides and

other substances, may be affecting human fertility. There is documented evidence that specific

exposures to compounds in the workplace have affected male fertility. There has also been a rise

in testicular cancer rates in the United States. Both of these conditions are related to increases in

male infertility. Increased risk factors of infertility in women may include:
            -  age

            -  stress

            -  poor diet

            -  athletic training
            -  being overweight or underweight

            -  tobacco smoking

            -  alcohol

            -  sexually transmitted diseases

            -  health problems that cause hormonal changes

Most healthy women under the age of 30 shouldn't worry about infertility unless they've been trying to get pregnant for at least a year. At this point, women should talk to their doctors about a fertility evaluation. Men should also talk to their doctors if this much time has passed. In some cases, women should talk to their doctors sooner. Women in their 30s who've been trying to get pregnant for six months should speak to their doctors as soon as possible. A woman's chances of having a baby decrease rapidly every year after the age of 30, so getting a complete and timely fertility evaluation is especially important. Some health issues also increase the risk of fertility problems, so women with the following issues should speak to their doctors as soon as possible:
            -  irregular periods or no menstrual periods
            -  very painful periods
            -  endometriosis 
            -  pelvic inflammatory disease
            -  more than one miscarriage
No matter how old you are, it's always a good idea to talk to a doctor before you start trying to get
pregnant. Doctors can help you prepare your body for a healthy baby. They can also answer questions on fertility and give tips on conceiving.

Tracking Reproductive and Birth Outcomes
Tracking can enhance existing surveillance data by creating indicators which the team has concluded

are more relevant for linkage to environmental exposure/hazard data, which are not currently being

routinely collected by existing surveillance systems.The Tracking Network includes data and

information about the following reproductive and birth outcomes:
      -  Indicator of Prematurity

      -  Indicator of Growth Restriction

      -  Indicator of Mortality

      -  Indicator of Fertility

      -  Indicator of Sex ratio at birth 

Rates of reproductive outcomes may differ across geographic access to care, level of care,
maternal personal and behavioral characteristics, etc. Vital statistics data are used to estimate these
indicators. There are some limitations to these data that should be kept in mind. Current data are not
always available because it can take weeks and even months before a record is received and
processed. This is often the case when a state resident gives birth out of state. Also, errors or
inconsistencies on the record may be discovered and require time to follow-up to verify.

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