Scientists identify a pattern that predicts which pregnant women likely to have complications

University of Wisconsin School of Medicine and Public HealthDec 6 2011

Poor mental health before pregnancy predicts which pregnant women are most likely to have a pregnancy complication and give birth to a low birth-weight baby, a new nationwide survey reveals.

Pregnancy complications occur in more than 30% of pregnancies, and almost eight percent of children are born low birth weight. Both pregnancy complications and being born low birth weight represent important public health issues that can cause future health problems for both mother and child.

Scientists at the University of Wisconsin School of Medicine and Public Health found a pattern that predicts which pregnant women are likely to have these issues: those who had mental health problems before pregnancy were 40% more likely to have any pregnancy complication and nearly two times more likely to have a low birth weight baby, after adjusting for other factors. Additionally, the researchers also found evidence that poor mental health before pregnancy may also be a risk factor for having a miscarriage or stillbirth.

"We need to be screening and treating women for poor mental health much earlier in their lives, especially before women become pregnant'' says Dr. Whitney Witt, the study's lead author and assistant professor in the department of population health sciences. "Timely and effective treatment for mental health problems before pregnancy may help reduce women's risk for pregnancy complications or having a low birth weight baby."

Severe pregnancy complications have a great effect on women's health and pose serious risks to her immediate and lifelong well-being. Being born low birth weight can have lasting effects on children, including worse long-term health, impaired growth and development, behavior problems, and social and cognitive limitations.

The researchers examined data on 3,373 pregnant women who were surveyed as part of the 1996-2006 Medical Expenditure Panel Survey, taking a "life course perspective" to determine the factors that influence negative obstetric outcomes, such as pregnancy complications (high blood pressure, toxemia, pre-eclampsia or eclampsia; anemia; diabetes, gestational diabetes, or high blood sugar; low-lying placenta; vaginal bleeding; or premature labor) and being born low birth weight (less than 2,500 grams).

They found several important disparities in obstetric outcomes, including:

- Black (non-Hispanic) women are 1.35 times more likely than white (non-Hispanic) women to experience any pregnancy complication.
- Women in families with a higher income are less likely than women with the lowest family income to experience any pregnancy complication.
- Compared to women who are married or living with a partner, unmarried women are more likely to have a miscarriage or stillbirth.
- Hispanic women are 40% less likely to have a miscarriage or stillbirth than white (non-Hispanic) women.
- Women with any publicly funded insurance are 43% less likely to have a miscarriage or stillbirth compared to women with private insurance; while uninsured women are more than twice as likely to have a miscarriage or stillbirth.
- Women with a college degree or higher are less likely than women with a high school degree to have a miscarriage or stillbirth.

Interestingly, while black (non-Hispanic) women have the highest rate of low birth-weight babies, Witt and her team found that this may be because black women are more likely to have a pregnancy complication, and women who experience any pregnancy complication are more than four times as likely to have a low birth weight baby.

Witt says, "Our research suggests that if we can prevent pregnancy complications in African-American women we may be able to eliminate the disparity in low birth weight. Intervening earlier in women's reproductive lives may help ensure that women of any race or ethnicity have an equal chance to deliver a healthy baby."