Predictors of Fetal Macrosomia and Cesarean C-Section in Women with Gestational Diabetes Mellitus

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 806-823-Gestational Diabetes
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-819
Ji Wei Yang*1, Thi Hoang Lan Nguyen1, Lena Salgado1, Elisabeth Codsi2, Patricia Lecca1, Catherine Adam1, Marie-Josée Bédard2 and Ariane Godbout1
1Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada, 2Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
Background: Gestational diabetes mellitus (GDM) has been associated with well-known obstetrical and perinatal complications such as macrosomia and increased rate of caesarean C-section (CS). Objective: To determine major predictors of macrosomia and CS in our GDM population. Methods: A retrospective study was carried out among pregnant women diagnosed with GDM between 2005 and 2011 and a cohort of non-diabetic women who delivered in 2011 at the CHUM. GDM was diagnosed if at least one of two values on the 75g oral glucose tolerance test (OGTT) was above local criteria: fasting plasma glucose (FPG) ≥5.0 or 2-hr post OGTT ≥7.8 mmol/L. Macrosomia was defined as birth weight (BW) >4kg or as large for gestational age (LGA) if BW was >90th percentile for a given gestational age. The following factors were analyzed: maternal age, ethnicity, parity, prior GDM or fetal macrosomia, OGTT values, HbA1C, family history of diabetes, pre-pregnancy body mass index (BMI), gestational weight gain (GWG), insulin therapy during pregnancy, fetal abdominal circumference (FAC) and estimated fetal weight (EFW) on third trimester ultrasound. Associations of each factor with macrosomia and CS rates were analyzed. Results: A total of 2436 pregnant women were included: 1653 with GDM (G1) and 783 without GDM (G2, control group). Compared to G2, G1 women were older, more often primiparous, and had higher pre-pregnancy BMI. Furthermore, G1 had a larger proportion of non-Caucasian women. In G1, predictors of macrosomia were maternal age (34.2 vs. 32.2), Hispanic or African origins (respectively 12% and 8% vs 6%), a pre-pregnancy BMI >30 (47.1 vs 24.4%), excessive GWG (mean of 12.9 vs 11.4kg), OGTT results (FPG: 6.6 vs 5.1 mmol/L; 2-hr post: 9.8 vs 8.4 mmol/L), HbA1C values (5.9 vs 5.4), insulin requirement during pregnancy (64 vs 60%), family history of diabetes (48 vs 36%), and FAC measured at 33 weeks of gestation (90.7 th vs 48.2 th percentile). Major risk factors for CS were previous CS (37% vs 5%), pre-pregnancy BMI >30 (31.5% vs 22%) and insulin therapy during pregnancy (63% vs 59%). Conclusions: In our GDM population, a pre-pregnancy BMI over 30 kg/m2, OGTT results (mostly FPG) and FAC at 33 weeks are independent predictors of macrosomia whereas previous CS and obesity are the major risks factors for CS. Though these risk factors were previously reported, identification of major predictors for macrosomia and CS in our high-risk GDM population, in whom strict diagnostic criteria are applied, allows improvement of present care.

Nothing to Disclose: JWY, THLN, LS, EC, PL, CA, MJB, AG

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