The 2009 Institute of Medicine guidelines recommend 11-20 pounds of weight gain during pregnancy for women with BMI ≥30, with 1.1-4.4 of this in the first trimester. However, many women are unaware of this and do not monitor their weight prior to initiating prenatal care. This study compares self-reported pre-pregnancy weight versus first prenatal visit weight in an obese, low-income population.METHODS:
A retrospective cohort of 1,440 women receiving care at a large Medicaid clinic from 2013-2016 with BMI ≥30 was reviewed. Women who initiated prenatal care before 14 weeks gestation were included. Self-reported pre-pregnancy weight was compared with weight at first prenatal visit using paired t-test. Demographic data was compared using unpaired t-test and ANOVA.RESULTS:
Inclusion criteria was met by 842 women, with mean gestational age of 9.2 weeks. Pre-gravid weight varied significantly from initial prenatal care weight, with mean absolute difference of 5.4 pounds (P<.001). 30.7% of patients had an increase in weight of greater than 5 pounds. There was no statistical significance between weight difference in planned versus unplanned pregnancies (P=.50). Patients with BMI>40 had a smaller difference between reported and first visit weights than those with BMI 30-34.9 (mean 0.64 vs 2.83 pounds, P<0.01).CONCLUSION:
In an obese, low-income population, self-reported and initial first-trimester visit weight can differ significantly. It is unclear if this is due to poor recall of pre-pregnancy weight or early weight gain. More awareness of pre-pregnancy weight and the guidelines regarding weight gain are needed prior to the initiation of prenatal care.