Fetal Interventricular Septum Thickness and Maternal Gestational Diabetes Control
Fetal Interventricular Septum Thickness and Maternal Gestational Diabetes Control
Glucose intolerance and gestational diabetes are common complications of pregnancy. Their
 prevalence varies worldwide secondary to differences in screening practices (one-step versus
 two-step approach) and population characteristics (increased maternal age, body mass index,
 ethnicity). Gestational diabetes mellitus is associated with increased incidence of
 macrosomia, operative vaginal delivery, shoulder dystocia, cesarean delivery, metabolic
 complications in the newborn and long-term risk of developing type II diabetes mellitus (HAPO
 2008).

 Early diagnosis and management of gestational diabetes mellitus, including dietary advice and
 insulin, improves maternal and fetal outcomes (Crowther 2005, Hartling 2013). Various
 strategies have been tested prenatally to detect those fetuses that might be adversely
 affected by gestational diabetes mellitus. For instance, the abdominal circumference
 measurement during routine fetal biometry was used successfully to identify pregnancies with
 a higher risk of fetal macrosomia (Schaefer-Graf 2003, De Reu 2008, Rosati 2010). In recent
 years, the fetal interventricular septum thickness, as detected by two-dimensional
 ultrasound, was shown to be significantly thicker in the presence of gestational diabetes
 mellitus, independently of maternal glycemic control, when compared to pregnancies with no
 gestational diabetes mellitus (Ren 2011, Garg 2014).

 Current guidelines focus on normalisation of maternal blood glucose concentration. Thus far
 no study has addressed whether measurement of the fetal interventricular septum thickness can
 predict adverse pregnancy outcome in euglycemic women with gestational diabetes mellitus.
Rational for the study If fetal interventricular septum hypertrophy in pregnancies with
 gestational diabetes mellitus appears prior to either fetal abdominal circumference
 measurement > 90th percentile or the abnormal maternal glucose levels, then future management
 of women with gestational diabetes mellitus might be targeted earlier at these pregnancies to
 ensure a more favorable outcome.

 Objective To determine the thickness of fetal interventricular septum in women with and
 without gestational diabetes mellitus and correlates it with perinatal outcome.

 Methods Study design This is a prospective study at Rambam Health Care Campus. Inclusion /
 Exclusion criteria

 1. Inclusion Study group - women between 24 - 34 weeks' gestation who were diagnosed with
 gestational diabetes mellitus or known with type I or type II diabetes mellitus.

 Control group - women between 24 - 34 weeks' gestation who do not have diabetes.

 2. Exclusion (that might affect directly or indirectly the fetal cardiac function) - women
 who did not complete a glucose challenge test, smoking, underlying cardiac or
 respiratory illness, fetal growth restriction, medicated hypertension disorder of
 pregnancy, multiple pregnancy, use of steroids for lung maturation in the current
 pregnancy and known major congenital anomalies.

 Study population Women who meet the above inclusion criteria will be asked to participate in
 the study, and will be asked to provide a written informed consent. Both groups, the study
 and control group, will be recruited when attending their routine prenatal care in the
 prenatal clinics at Rambam Health Care Campus. Eligible woman will undergo ultrasound
 examination as they would normally do in each visit. This study, under no circumstances, will
 alter the participants routine care.

 Data Collection

 1. Maternal and fetal characteristics Data related to the fetomaternal antenatal,
 intrapartum and postpartum course will be recorded prospectively (Appendix 1).

 2. Ultrasound assessment Basic transabdominal two-dimensional ultrasound examination using
 B-mode (either Samsung or Voluson E8), will be carried out first to assess fetal growth
 and well-being. This is to be continued with a more detailed ultrasound, with a specific
 focus on the fetal interventricular septum. The entire length of the study, dependent on
 fetal lie, is expected to take around 15 min. The results of the assessment of fetal
 growth and well-being will be provided to the patient.

 The measurement of the fetal interventricular septum will be as follow (Figure 1 below);
 maternal suspended respiration, without fetal movement or breathing, level of the 4-chamber
 view with adequate magnification of the fetal heart (50% of the screen), midpoint of
 interventricular septum with cine loop to end-diastolic (maximum ventricular filling), and
 average of 3 measurements (Ren 2011, Garg 2014).
Inclusion Criteria:

 -  Study group - women between 24 - 34 weeks' gestation who were diagnosed with
 gestational diabetes mellitus or known with type I or type II diabetes mellitus.

 Control group - women between 24 - 34 weeks' gestation who do not have diabetes.

 Exclusion Criteria:

 -  women who did not complete a glucose challenge test, smoking, underlying cardiac or
 respiratory illness, fetal growth restriction, medicated hypertension disorder of
 pregnancy, multiple pregnancy, use of steroids for lung maturation in the current
 pregnancy and known major congenital anomalies.