541 Short interpregnancy intervals and healthservices utilization: is neonatal hospital readmissionassociated with short intervals?Allison Bryant1, Erin Madden2

1Massachusetts General Hospital, Vincent Obstetrics & Gynecology,Maternal Fetal Medicine, Boston, MA, 2Veteran’sResearch Institute, NCIRE, San Francisco, CAOBJECTIVE: Short interpregnancy intervals (IPI) are associated withpreterm birth. We explored whether birth-to-conception intervalsless than 6 months are associated with neonatal hospital readmissionabove and beyond the effects prematurity.STUDY DESIGN: Data from vital statistics records for all births in Cali-fornia between 1999 and 2004 were linked with hospital dischargedata. For women with a first birth in 1999-2000 and a second beforethe end of 2004, multivariable logistic regression was used to deter-mine risk factors for hospital readmission for neonates any time in thefirst year of life. Negative binomial regression was used to determinerisk factors for total length of neonatal hospital stay (LOS), excludingthe birth admission.RESULTS: Of 190,889 infants born to mothers meeting inclusion cri-teria, 20,015 (10%) were readmitted during the first year of life. Theleading diagnoses for these admissions included respiratory (20%),infectious (12%), gastrointestinal/dehydration/nutrition (10%),jaundice (6%) and cardiac etiologies(6%). Factors associated withreadmission are presented in the Table, and include IPI � 18 months(8 vs. 6d, p�0.001). IPI was not statistically significantly associatedwith neonatal LOS once gestational age at birth was accounted for.CONCLUSION: Short IPI is associated with increased use of health careresources: independent of gestational age, IPI � 6 months is associ-ated with a greater risk of hospital readmission for neonates. Theoverall length of stay for these admissions does not vary by IPI inde-pendent of IPI’s association with prematurity, a risk factor for in-creased hospital utilization in the first year of life.

542 Short interpregnancy intervals and healthservices utilization: is maternal antepartumadmission associated with short intervals?Allison Bryant1, Erin Madden2

1Massachusetts General Hospital, Vincent Obstetrics & Gynecology,Maternal Fetal Medicine, Boston, MA, 2Veteran’s HealthResearch Institute, NCIRE, San Francisco, CAOBJECTIVE: The risk of compromise to maternal health is not clearamong women with short interpregnancy intervals (IPIs). We exam-ined the association between birth-to-conception intervals of lessthan 6 months and maternal hospitalization during pregnancy forreasons other than delivery.STUDY DESIGN: Data from vital statistics records for all births in Cali-fornia between 1999 and 2004 were linked with hospital dischargedata. For women with a first birth in 1999-2000 and a second before

the end of 2004, multivariable logistic regression was used to deter-mine risk factors for antepartum (AP) hospital admission and nega-tive binomial regression was used to determine independent risk fac-tors for total length of AP hospital stay.RESULTS: Of 188,596 women meeting inclusion criteria, 6% had an APadmission. Several characteristics were associated with having had anAP admission in multivariable analyses, including IPI � 6 months(Table). This association was not entirely explained by taking intoaccount maternal diagnoses of hypertension, preterm labor, gesta-tional diabetes and antepartum hemorrhage. Among women whowere hospitalized, IPI was not independently associated with totallength of hospital stay.CONCLUSION: Short interpregnancy interval appears to be associatedwith increased maternal health services utilization, in this case, ante-partum hospital admission. This increased risk is not completely me-diated by common conditions requiring admission during pregnancy.

543 Hyperemesis gravidarum-related hospitalizationsand emergency room visits: characterizationsand trends, 2000-2009Amin Ramzan1, Marlena Fejzo2, Patrick Mullin3

1University of Southern California, Keck School of Medicine, Los Angeles,CA, 2University of California, Los Angeles, Department of Medicine,Los Angeles, CA, 3University of Southern California, Keck School ofMedicine, Department of Maternal-Fetal Medicine, Los Angeles, CAOBJECTIVE: Hyperemesis gravidarum (HG) represents the far end ofthe spectrum of nausea and vomiting during pregnancy. The purposeof this study is to examine the trends and characteristics of HG-relatedhospitalizations and emergency department visits during the decadespanning 2000-2009.STUDY DESIGN: We used publicly available data from the HealthcareCost and Utilization Project (HCUP). Hospitalizations and emer-gency room visits for HG and other complications of pregnancy wereidentified using ICD-9 codes. Hospitalization rates, mean length ofstay and mean total charges were calculated for the years 2000 through2009 and were compared based on patient and hospital characteris-tics.RESULTS: Hospitalizations with HG as the primary diagnosis de-creased from 34,307 in 2000 to 22,638 in 2009 (-34%). All other com-plications of pregnancy experienced a similar drop in hospitalizationsduring the decade. Conversely, from 2006-08, the only years with EDdata available, there was an increase in treat and release ED visitsyear-to-year with HG listed as the primary diagnosis, ranging from162,702 to 167,916 visits. Among other complications of pregnancyanalyzed, only genitourinary infections accounted for more treat andrelease ED visits during this period. The national cost of treating HGin the inpatient setting increased 50% from $167 million in 2000 to$250 million in 2009. ED visit costs for HG or other complications ofpregnancy were not available.

PosterSessionIV Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health www.AJOG.org

S246 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2012