Introduction:
Excessive gestational weight gain (GWG) is associated with adverse outcomes for women and infants (gestational hypertension, cesarean delivery, postpartum weight retention and large for gestational-age infants). Current population-based trends in GWG are unknown. This study estimates current trends in mean GWG and trends in gaining below, within, and above the 1990 IOM recommendations among women who delivered live births in multiple states from 2000-2009.
Methods:
We included Pregnancy Risk Assessment Monitoring System (PRAMS) data from 95,025 women ≥18 years of age, who delivered a singleton infant between 39-40 weeks gestational age in one of 14 states during 2000 through 2009. We defined self-reported GWG in pounds as a continuous variable and as a three-level categorical variable according to 1990 IOM recommendations (below, within and above recommendations). Self-reported pre-pregnancy weight and height from PRAMS were used to calculate pre-pregnancy body mass index and gestational weight gain was extracted from the birth certificate. We grouped live births into 5 biennial intervals and estimated percentage point changes in prevalence using the beta coefficient of the biennial intervals. Adjusted trends in gaining below or above (compared to within) IOM recommendations for GWG from 2000-2001 to 2008-2009 were assessed using multivariable multinomial linear regression. We examined the trend in mean GWG from 2000-2001 to 2008-2009 using multivariable linear regression adjusted for maternal and pregnancy characteristics. SUDAAN was used to account for the complex sampling design and weights were used to provide population-based estimates.
Results:
There was a 0.9 biennial percentage point increase in the percent of women gaining above IOM recommendations, from 43% in 2000-2001 to 46% in 2008-2009 (p- trend < 0.01). Women gaining within IOM recommendations decreased at a rate of 1.1 percentage points biennially, from 38% in 2000-2001 to 34% in 2008-2009 (p-trend <0.01). There was a statistically significant increase in the adjusted odds of gaining above (odds ratio (OR) = 1.2, 95% confidence interval (CI: 1.1-1.2) and below (OR= 1.2, 95% CI: 1.1-1.3) IOM recommendations over time. From 2000-2009, there was no change in mean GWG.
Conclusion:
From 2000-2009, there was a modest increase in the percent of women gaining above IOM recommendations while mean GWG remained constant. These seemingly contradictory findings may be due to a larger percentage of women entering pregnancy overweight and obese and gaining above recommended limits. Results from this analysis highlight the need for continued clinical and public health efforts to develop and implement effective strategies to ensure women enter pregnancy at a healthy weight and achieve recommended GWG.
Trends in gestational weight gain: the Pregnancy Risk Assessment Monitoring System, 2000–2009