Factors influencing inadequate and excessive weight gain in pregnancy: Colorado, 2000-2002.

OBJECTIVES: To identify the biological, psychosocial, and behavioral characteristics that are associated with inadequate and/or excessive weight gain in pregnancy.
METHODS: Univariate, bivariate, and multiple logistic regression analyses were conducted using data from Colorado's 2000-2002 Pregnancy Risk Assessment Monitoring System (PRAMS). Independent variables included biological risk factors (prepregnancy BMI, parity, preterm labor, maternal morbidity), psychosocial risk factors (pregnancy intention, WIC and Medicaid enrollment, area of residence, age, race/ethnicity, education, and stressors), and behavioral risk factors (smoking and drinking alcohol in the last trimester of pregnancy).
RESULTS: In the bivariate analysis, all the biological risk factors were significantly associated with the pregnancy weight gain distribution, as were several of the psychosocial risk factors (WIC and Medicaid enrollment, area of residence, race/ethnicity, and maternal education). Smoking and alcohol use were not significant. After controlling for other variables through logistic regression, the only characteristics associated with inadequate weight gain were parity, underweight or obesity, preterm labor, nausea, residence in a rural area, low levels of education, and smoking. The characteristics associated with excessive weight gain were overweight or obesity, high blood pressure, and having 12 years of education.
CONCLUSION: Having a pre-pregnancy BMI above 29 greatly increases the risk for both inadequate and excessive weight gain. Unfortunately, obesity, like the other major risk factors identified here (maternal education and parity) are not modifiable after a given pregnancy begins. To address these problems, a sustained approach to women's health, education, and well-being across the lifespan will be required, rather than a reliance upon targeted interventions during pregnancy.