Reference values for fetal aortic isthmus blood flow parameters at 24 to 38 weeks' gestation.

OBJECTIVE: The goal of this study is to establish population-specific nomograms of fetal aortic isthmus (AoI) Doppler indices in the period of 24-38 weeks' gestation. METHODS: This was a cross-sectional study of 240 Asian singleton pregnant women at 24-38 completed weeks' gestation. Fetal AoI blood flow was evaluated by Doppler study with automatic calculation of pulsatility index, resistance index, peak systolic velocity, end-diastolic velocity, and time-averaged maximum velocity. The relationship of these indices and gestational age was estimated by using regression analysis, and the best predictive models were determined to define mean, 5th, and 95th centile of each gestational age. The reproducibility was expressed by intraclass correlation coefficients and limits of agreement. RESULTS: The mean maternal age was 28 ± 5.7 years. A total of 97% of all attempts to obtain AoI Doppler waveforms were successful with high interobserver and intraobserver reproducibility. Pulsatility index and peak systolic velocity significantly correlated with gestational age (P = 0.03 and 0.001, respectively), whereas no significant change of resistance index, end-diastolic velocity, and time-averaged maximum velocity with advancing gestation was observed. CONCLUSION: This study offers normative values of fetal AoI Doppler indices, which may be useful in the difficult task of fetal surveillance in growth-restricted fetuses among our population.

Incidence of gestational diabetes mellitus among pregnant women with one abnormal value of oral glucose tolerance test.

OBJECTIVE: To compare the incidence of Gestational Diabetes Mellitus (GDM) between pregnant women with one abnormal value of oral glucose tolerance test (Study group) and those with normal screening test (Control group) and compare their pregnancy outcomes. DESIGN: Retrospective cohort study. SETTING: Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital. MATERIAL AND METHOD: Two hundred and twenty eight at-risk pregnant women were enrolled from January 2003 to November 2004. They were divided equally with 114 each in study and control group. All received GDM screening before 24 weeks of gestation following the guidelines used at Siriraj Hospital. Data collection included baseline characteristics, data on clinical risks and screening results, final diagnosis, maternal and neonatal complications. Incidence of GDM and pregnancy outcomes was compared between the two groups. RESULTS: Both groups' baseline characteristics and clinical risks were comparable, except that the mean age of women in the study group was significantly greater than in the control group (32.8 +/- 4.9 and 29.7 +/- 5.5 years, p < 0001). The incidence of GDM was significantly higher among in study group compared with the control group (21.9% and 1.8% respectively, RR 12.5, 95%CI 3.0-51.5). After adjusting for maternal age, abnormal one OGTT value was the only independent risk for developing GDM (adjusted OR 16.3, 95%CI 3.7-71.9, p < 0.001). Infants of the study group had significantly higher birth weight than those of the control group (3203.6 +/- 563.9 and 3050.7 +/- 457.8 g respectively, p = 0.026). Rate of primary cesarean section, asphyxia, macrosomia, low birth weight, and other neonatal complications were comparable between the two groups. CONCLUSION: Pregnant women with one abnormal value of oral glucose tolerance test had a significantly greater risk of developing GDM compared to women with normal screening test. Pregnancy outcomes between the two groups were not significantly different.