Interventricular Septal Thickness of Thai Fetuses: at 32 to 35 Weeks’ Gestation
Lawan Patchakapat MD*, Boonchai Uerpairojkit MD*, Teera Wacharaprechanont MD*, Saknan Manotaya MD*, Somchai Tanawattanacharoen MD*, Dhiraphongs Charoenvidhya MD*
Affiliation : * Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University
Objective : To establish the normal value of fetal InterVentricular Septal Thickness (IVST) from 32 to 35 weeks’
gestation in Thai fetuses.
Materials and Methods : Thai pregnant women with normal fetuses were recruited for prenatal 2-dimensional
M-mode echocardiographic measurements of fetal IVST at 32 to 35 weeks’ gestation. All had a confirmed
gestational age, normal structural scanning and negative diabetic screening at 24 to 28 weeks’ gestation. The
IVST was measured from the 4-chamber view during diastole and systole. The 5th, 50th and 95th percentile of
the IVST during Diastole (IVSD) and the IVST during Systole (IVSS) were demonstrated. The relationship
between the IVSD and IVSS and gestational age were determined.
Results : A total of 410 measurements were obtained. The normal values of the IVSD and IVSS according to
gestational age were presented as 5th, 50th and 95th percentile ranks. The correlation coefficients (r) between
the IVSD and IVSS and gestational age were 0.11 and 0.12, respectively. The IVSD and IVSS were not statis-
tically different with advancing gestation. The 95th percentile of the IVSD was 4.51 millimeters (mm) (range =
4.26 to 4.74 mm) and IVSS was 6.23 mm (range = 5.96 to 6.68 mm). The intraobserver variability was 7.6%.
Conclusion : The normal values of fetal IVSD and IVSS in a Thai population from 32 to 35 weeks’ gestation
were established. This could be used as a baseline data in detecting the asymmetrical septal hypertrophy
during fetal life.
Keywords : Interventricular septal thickness, Fetal echocardiography
