BMI‐based Prenatal Vitamins in Obese Pregnancy: Cohort Profile

Background In the United States, one in three women is obese before pregnancy. Obesity is associated with inflammation and oxidative stress, which has been implicated in fetal programming of obesity. Objective The Prenatal Vitamin (PNV) Study is a randomized controlled trial of a BMI‐based prenatal vitamin, formulated to have higher concentrations of vitamins C, E, B 6 , and folic acid, compared to a standard prenatal vitamin in obese pregnant women. We have previously found that obese pregnant women have lower concentrations of these antioxidant micronutrients, and higher inflammation and oxidative stress compared to lean pregnant women. The overall objective of the PNV study is to determine whether providing a BMI‐based supplement to obese pregnant women will decrease markers of inflammation and oxidative stress. Here we report the baseline demographics and perinatal outcomes for 130 subjects enrolled in this study. Methods Obese pregnant women (BMI≥30kg/m 2 ) were recruited between 2014 and 2016 in Boston, MA. Exclusion criteria included women with a gestational age >13 weeks at the time of consent, plans to move from the immediate area within one year of birth and pre‐existing diabetes, autoimmune disease or stage two or three hypertension. We collected information from mothers using questionnaires and obtained clinical information from their medical record. Results From the 113 eligible women, 4 pregnancies ended in miscarriages and 68 women have delivered live births to date. The mean BMI of the cohort was 35.6kg/m 2 . Subjects were similar to the Massachusetts population in terms of age at pregnancy, level of education and racial composition. 60% of women delivered by vaginal delivery, the mean gestational age of infants was 37.7 weeks, with 23% of infants born ≤37 weeks. Mean birth weight was 3.14kg. Interestingly, 81% of subjects planned to exclusively breastfeed at delivery, but only 60% were exclusively breastfeeding at hospital discharge. Conclusions The overall demographics of this cohort of obese women were similar to the population of Boston. The perinatal characteristics suggest that women were more likely to deliver preterm and have a cesarean section delivery than the overall population. Breastfeeding initiation and early continuation are strikingly lower than the overall population, despite high rates of intention to exclusively breastfeed. Support or Funding Information This study was supported by a K23 grant from the NIH (ref. no. K23HD074648) and The Charles H. Hood Pediatric Research Grant 1 Characteristics of PNV Study CohortMaternal Characteristics N=113Age at Enrollment (years): mean(SD) 30.7 (5.7)BMI at Enrollment (m 2 /kg): mean(SD) 35.6 (5.5)Gestational Age at Enrollment (weeks): mean(SD) 10.2 (2.0)Parity: n(%)1 7 (6) 2 19 (17) 3 28 (25) >3 59 (52)Ethnicity: n(%)Hispanic 47 (42)Race: n(%)Asian 2 (2) Hawaiian or Pacific Islander 1 (1) Black or African American 31 (27) White or Caucasian 48 (43) More than One Race 9 (8) Unknown/Not Reported 22 (19)Marital Status: n(%)Single 38 (34) Married 57 (50) Other 18 (16)Education: n(%)Some High School 4 (4) High School Diploma/No Bachelor's Degree 24 (22) Some College/Bachelor's Degree/Professional Degree 81 (74)Household Income: n(%)<$20,000 30 (29) $20,000–$50,000 35 (34) $50,000–$70,000 12 (11) $70,000–$100,000 5 (5) >$100,000 22 (21)Insurance (private=yes): n(%)Yes 54 (48)Perinatal Outcomes N=68Gestational Age at Delivery (weeks): mean (SD) 37.7 (3.0)Mode of Delivery: n (%)Vaginal 38 (62)Infant Birth Weight (kilograms): mean (SD) 3.15 (0.7)Infant Birth Length (centimeters): mean (SD) 48.3 (5.7)Intention to Exclusively Breastfeed: n (%)Yes 52 (81)Exclusively Breastfeeding at Hospital Discharge: n (%)Yes 37 (60)