Key Findings: Modeling the Potential Public Health Impact of Prepregnancy Obesity on Adverse Fetal and Infant Outcomes

The journal Obesity has published a new study online: “Modeling the Potential Public Health Impact of Prepregnancy Obesity on Adverse Fetal and Infant Outcomes.” You can read the article’s abstract here. See below for a summary of the findings from this article.

Main Finding from These Studies:

Many birth defects and fetal deaths could be prevented if women could reach and maintain a healthy weight before becoming pregnant. For example, if no U.S. women were obese when they became pregnant and instead attained a healthy weight before pregnancy, nearly 7,000 fetal deaths could be prevented. And, about 2,800 babies could be born without a heart defect each year. Even if the number of obese women in the U.S. was reduced by about 10%, nearly 700 fetal deaths and about 300 congenital heart defects could be prevented each year. While this study used methods that involve some level of uncertainty, it suggests that preventing or reducing obesity before pregnancy could impact infant health.

Background Information

• How common is obesity among women of reproductive age?
  About 1 in 3 U.S. women between the ages of 20 and 39 is obese.¹ As an example, a women who is 5 foot 5 inches tall would be considered obese if her weight was 180 pounds or higher. In recent years, the number of obese women has been increasing. In 1999-2000, about 28% of U.S. women aged 20-39 years were obese. This increased to 34% in 2007-2008.¹
• Is obesity harmful for women and their babies?
  Studies have shown that obesity might cause problems for women and their babies. For women, obesity is linked to diabetes during pregnancy, C-section deliveries, and high blood pressure during pregnancy.^2-4 For babies, obesity in the mother could increase the risk for fetal death, some birth defects, and some types of preterm birth.^5-8
• What are some ways that women can reach a healthy weight before becoming pregnant?
  The key to achieving and maintaining a healthy weight isn't about short-term dietary changes. It's about a lifestyle that includes healthy eating and regular physical activity. It is important for women to stay in control of their weight; it contributes to good health now and as they age.

  If a woman is underweight, overweight, or obese, it is important for her to talk with her doctor or other health care professional about ways to reach and maintain a healthy weight before pregnancy. Dieting during pregnancy is usually not recommended. Learn more about healthy weight.

About this Study

• What did this study look at?
  This study examined how many more babies would be born healthy in the US if women were a healthy weight (and not obese) before becoming pregnant. Specifically, researchers estimated the number of fetal deaths and the number of birth defects that could be prevented if obesity was reduced or eliminated before pregnancy.
• What were the study results?
  Researchers found that many health problems for babies could be prevented if obesity was reduced or eliminated among women who might become pregnant.
  • If obese women were able to achieve a healthy weight before becoming pregnant,
    • Nearly 7,000 fetal deaths or stillbirths could be prevented
    • About 2,800 babies could be born without a heart defect
    • Nearly 500 babies could be born without hydrocephalus (a birth defect often called water on the brain)
    • About 400 babies could be born without spina bifida (a major birth defect of the spine)
    • If the number of U.S. women who are obese before pregnancy was reduced by about 10%, nearly 300 heart defects and about 700 fetal deaths could be prevented each year.
• Why is this study important?
  This study shows that efforts to reduce obesity among women who might become pregnant could improve the health of babies. These efforts also could have a major public health impact, given the cost and health service resources associated with birth defects and chronic health conditions, like diabetes, among women. Importantly, this study emphasizes the need to encourage women of reproductive age to reach and maintain a healthy weight or strive to be physically active before becoming pregnant.

To learn more about birth defects, visit www.cdc.gov/birthdefects

References

1. Flegal KM, Carroll MD, Ogden CL, Curtin LR. Prevalence and trends in obesity among US adults, 1999-2008. JAMA 2010;303(3):235-41.
2. Chu SY, Callaghan WM, Kim SY, Schmid CH, Lau J, England LJ, et al. Maternal obesity and risk of gestational diabetes mellitus. Diabetes Care 2007;30(8):2070-6.
3. Chu SY, Kim Sy, Schmid CH, Dietz PM, Callaghan WM, Lau J, et al. Maternal obesity and risk of cesarean delivery: a meta-analysis. Oves Rev 2007;8(5):385-94.
4. O’Brien TE, Ray JG, Chan WS. Maternal body mass index and the risk of preeclampsia: a systematic overview. Epidemiology 2003;14(3):368-74.
5. Chu SY, Kim SY, Lau J, Schmid CH, Dietz PM, Callaghan WM, et al. Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet Gynecol 2007;197(3):223-8.
6. Stothard KJ, Tennant PW, Bell R, Rankin J. Maternal overweight and obesity and the risk of congenital anomalies: a systematic review and meta-analysis. JAMA 2009;301(6):636-50.
7. Waller DK, Shaw GM, Rasmussen SA, Hobbs CA, Canfield MA, Siega-Riz AM, et al. Prepregnancy obesity as a risk factor for structural birth defects. Arch Pedatr Adolesc Med 2007;161(8):745-50.
8. McDonald SD, Han Z, Mulla S, Beyene J. Overweight and obesity in mothers and risk for preterm birth and low birth weight infants: a systematic review and meta-analyses. BMJ 2010;341:c3428.

Reference for Key Findings Feature

Honein MA, Devine O, Sharma AJ, Rasmussen SA, Park S, Kucik JE, Boyle C. Modeling the Potential Public Health Impact of Prepregnancy Obesity on Adverse Fetal and Infant Outcomes. Obesity 2012. [epub ahead of print].