571: Trends in birth weight and ponderal index of preterm singleton infants over 15 years at an urban tertiary center

singleton infants over 15 years at an urban tertiary center Kelly Gibson, Thaddeus P. Waters MetroHealth Medical Center-Case Western Reserve University, Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Cleveland, OH, MetroHealth Medical Center Case Western Reserve University, Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Cleveland, OH OBJECTIVE: To determine if there have been changes in birth weight (BW) and Ponderal Index (PI: gram/cm3) in preterm newborns across a fifteen year time period after controlling for population changes. STUDY DESIGN: This is a retrospective cohort analysis of data collected within a perinatal database at an urban tertiary center. We included liveborn singletons delivered between 28 0/7 and 36 6/7 weeks, and from 1/1995 to 12/2009. BW outliers (99th %ile for gestational age (GA) were excluded). Trends in BW and PI over time were evaluated. We divided the data into five year epochs. ANOVA, chi-squared, and linear stepwise regression analyses were used as appropriate. Regression analyses controlled for GA, maternal race, age, parity, smoking, BMI at delivery, diabetes (IDDM), hypertension (HTN), and delivery indication. RESULTS: 5,132 infants were included. Mean BW ( 118g), PI ( 0.13g/cm3), and GA ( 0.57wk) increased significantly over time (P 0.001 for each). Significant differences over time (p 0.001) were also found for maternal age ( 0.6yr), smoking ( 7.0%), IDDM ( 1.9%), nulliparity ( 4.9%), PROM ( 10.2%), and race (African Americans 7.4%), but not for BMI or HTN. Labor Inductions increased ( 5.0%; p 0.001) while spontaneous preterm labor decreased ( 5.6%; p 0.001). In stepwise regression (R2 0.52; Table), GA was the most highly associated factor affecting BW, followed by IDDM, HTN, infant gender, smoking, parity, and PROM. Year of delivery and maternal BMI were not significant factors. Regarding PI, stepwise regression (R2 0.025, p 0.045) found GA, year of delivery, HTN, and IDDM to be significantly associated factors. CONCLUSION: Over fifteen years, BW and PI of singleton infants born at 28-36 weeks GA have increased. The majority of this change is attributed to increased GA within this preterm cohort, and to changes in maternal social and medical demographic characteristics. PI, but not BW, has increased over time after controlling for factors likely to impact fetal growth. 572 Trends in severe obstetric morbidity Natalie Brooke Heath, Sean Esplin, Erick Henry, Cindy Weng, Michael Varner University of Utah School of Medicine, Obstetrics and Gynecology, SLC, UT, Intermountain Healthcare, Maternal-Fetal Medicine, Salt Lake City, UT, University of Utah, Biomedical Informatics, Salt Lake City, UT, University of Utah Health Sciences Center, Obstetrics and Gynecology, Salt Lake City, UT OBJECTIVE: To identify the contemporary occurrence and temporal trends of severe maternal morbidity in a large vertically integrated healthcare system. STUDY DESIGN: The data warehouse of a large vertically integrated healthcare system was searched for women delivering a singleton pregnancy delivered between July 2001 and December 2008. Severe maternal morbidity was defined as one or more of the following: ICU admission, cesarean hysterectomy, transfusion, uterine rupture, eclampsia, pulmonary embolism, cerebrovascular hemorrhage, intubation, cardiomyopathy or readmission within 6 weeks of discharge. Cases were identified by ICD-9 discharge diagnoses. Maternal demographic parameters, pregnancy outcome information and pre-existing conditions were also analyzed using univariate and multivariate logistic regression. RESULTS: 240,331 singleton births occurred during the study period. Severe maternal morbidity increased from 90.1 to 134.8 per 10,000 deliveries over the study period and was driven primarily by increased ICU admissions and transfusions (Figure). Overall cesarean delivery rates increased from 15.38% to 20.38%. However, rates of uterine rupture and pulmonary embolism decreased over the study period (Table). Each of the pre-existing medical conditions (chronic hypertension, chronic renal disease, diabetes and lupus) was associated with having a higher incidence of severe maternal morbidity. Women with pre-existing medical conditions were also more likely to be delivered abdominally. CONCLUSION: The rate of severe maternal morbidity increased over the study period primarily due to increased ICU admission and transfusion rates. Cesarean delivery rates also increased over the study period, and the increased incidence of transfusion is associated with this trend. PosterSessionIV Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health www.AJOG.org