202 The association between maternal insulinresistance in mid pregnancy and neonatal birthweight in uncomplicated pregnanciesHiroshi Yamashita1, Masashi Fukuda1, Yukari Kugishima1,Yuki Yamauchi1, Akiko Kuzume1, Takashi Hashimoto1,So Sugimi1, Naoko Yatsunami1, Sachie Suga1,Nobuko Kusuda1, Ichiro Yasuhi1

1Nagasaki Medical Center, Obstetrics and Gynecology, Omura-city, JapanOBJECTIVE: The purpose of this study was to determine whether ma-ternal insulin resistance measured by homeostasis model assessment-insulin resistance (HOMA-IR) in mid pregnancy is associated withneonatal birth weight in uncomplicated pregnancies.STUDY DESIGN: We included singleton pregnant women who had a 75goral glucose tolerance test (OGTT) during mid pregnancy because ofa positive gestational diabetes (GDM) screen. We measuredHOMA-IR derived from fasting plasma glucose and immuno-reactiveinsulin concentration at OGTT. Women with GDM, hypertension, orfetal malformation were excluded. Using multiple and logistic regres-sion analysis to adjust for confounding variables including maternalage, prepregnancy body mass index (BMI), plasma glucose levels atOGTT, and gestational age (GA) at delivery, we tested the relation ofmid pregnancy maternal HOMA-IR to neonatal birth weight andlarge for GA (LGA) infants.RESULTS: We included 557 Japanese pregnant women. The mean ma-ternal age, prepregnancy BMI, GA at OGTT, and HOMA-IR, GA atdelivery, and birth weight were 31.8�/�5.0 years, 22.0�/�3.7 kg/m2, 30.5�/�4.0 weeks, and 1.46�/�0.8, 39.0�/�1.7 weeks, and3,030�/�470 g, respectively. HOMA-IR was positively associatedwith birth weight after controlling confounding variables (p�.05).Higher HOMA-IR was significantly associated with an increased in-cidence of LGA infants (n�38) with the adjusted odds ratio of 1.71 perone unit of HOMA-IR (95% confidence interval, 1.11-2.66).

CONCLUSION: Our findings suggest that the degree of maternal insulinresistance measured by HOMA-IR during mid pregnancy is associ-ated with birth weight in uncomplicated pregnancies. Mid pregnancyHOMA-IR could be a predictor of fetal overgrowth, independent ofmaternal glucose levels and obesity.

203 Indices of insulin resistance and �-cell functionin women with gestational diabetes, pregnancy-induced hypertension, and preterm deliveryHiroshi Yamashita1, Masahi Fukuda1, Yukari Kugishima1,Yuki Yamauchi1, Akiko Kuzume1, Takashi Hashimoto1,So Sugimi1, Naoko Yatsunami1, Sachie Suga1,Nobuko Kusuda1, Ichiro Yasuhi1

1Nagasaki Medical Center, Obstetrics and Gynecology, Omura-city, JapanOBJECTIVE: The purpose of this study was to evaluate indices of insulinresistance and insulin secretion in women with obstetric complica-tions, including gestational diabetes (GDM), pregnancy-induced hy-pertension (PIH), and preterm delivery (PTD) in Japanese pregnantwomen.STUDY DESIGN: Singleton pregnant women who had a 75g oral glucosetolerance test (OGTT) during mid pregnancy because of a positiveglucose challenge test were included. We used indices of homeostasismodel assessment (HOMA)-insulin resistance (HOMA-IR) andHOMA beta cell (HOMA-�) at OGTT as a function of maternal in-sulin resistance and �-cell function, respectively. We examinedwhether these indices were associated with GDM, PIH, and PTD. Weused logistic regression analysis to adjust for confounding variablesincluding maternal age and prepregnancy body mass index (BMI).RESULTS: Six hundred forty-six women were enrolled. The mean ma-ternal age, prepregnancy BMI, and gestational age at OGTT was31.9�/�5.0 years old, 22.4�/�4.2 kg/m2, and 30.4�/�4.0 weeks,respectively. Fifty-eight women were diagnosed as having GDM, and52 and 29 women developed PTD and PIH, respectively. BothHOMA-IR and HOMA-�were significantly different between womenwith and without GDM. Women with HOMA-IR of �75th percentilewere associated with GDM (adjusted odds ratio [OR], 2.46; 95% con-fidence interval [CI], 1.33-4.55), and women with HOMA-� of �25thpercentile were significantly less associated with GDM (adjusted OR,0.46; 95%CI, 0.25-0.83). In regard to PIH, not HOMA-IR butHOMA-� was significantly higher in women with PIH than in womenwithout PIH, and the association was persistent after adjusting forconfounders. PTD did not associate with either index.CONCLUSION: Our findings suggest that, independent of maternal obe-sity, in Japanese women, both increased insulin resistance and im-paired �-cell function are independently associated with GDM, andenhanced �-cell function is associated with development of PIH.

Poster Session I Clinical Obstetrics, Medical-Surgical-Disease, Neonatology, Physiology-Endocrinology www.AJOG.org

S102 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2012