ObjectiveTo test the hypothesis that left atrial shortening fraction is lower in fetuses of diabetic mothers than in fetuses of mothers with no systemic disease.
Methods
Forty-two fetuses of mothers with previous diabetes or gestational diabetes and 39 healthy fetuses of mothers with no
Key words fetal echocardiography, fetal diastolic function, global left atrial shortening fractionAlterations in left ventricular relaxation, filling, and compliance are common in fetuses of diabetic mothers. Some studies have suggested that the unidimensional echocardiographic profile of the left atrium may be used as an indicator of abnormalities in left ventricular diastolic function, and that left atrial shortening fraction is proportional to compliance and inversely proportional to left ventricular stiffness constant. The usefulness of atrial shortening as a parameter for assessing fetal diastolic function has not yet been demonstrated.Gestational diabetes has an incidence of 3.5%, accounting for high morbidity and mortality both for the fetus and mother. Major congenital anomalies affect 4 to 12% of newborn infants of women with clinical diabetes, representing an incidence of malformations approximately 5 times higher than that in the general population. The fetal heart is one of the most affected organs, and 40 to 50% of the congenital defects are located in the cardiovascular system 1,2 . Becerra et al 3 have reported an absolute risk for major cardiac malformations of 8.5 per 100 live-born infants of diabetic mothers.The increased tendency towards the appearance of disproportional myocardial hypertrophy, especially of the interventricular septum, has already been demonstrated in children of diabetic mothers 4 . The appearance of fetal echocardiography has provided the opportunity to study the disease in the prenatal period, when it is called fetal myocardial hypertrophy 5,6 . Several case series studied have reported an approximate 30% prevalence of that anatomical change in children of diabetic mothers. Septal hypertrophy has been reported as early as 21 weeks of gestational age, but the prevalence is greater in the third trimester 7,8 . Thus, fetal echocardiography should be performed in all pregnancies complicated with diabetes mellitus, because fetal myocardial hypertrophy is frequent, easily detected on examination, and is a potential cause for nonimmune hydrops. Fetal myocardial hypertrophy is characterized by interventricular septum dimensions at the end of diastole greater than 2 standard deviations according to gestational age or greater than 5mm, as this value is greater than 2 standard deviations until the end of pregnancy 6 . Myocardial hypertrophy involving the right ventricle and left ventricular posterior wall may occur, but septal hypertrophy is usually more marked. The presence of a gradient in the left ventricular outflow tract reveals the obstructive forms of the disease. The changes in myocardial compliance and relaxation cause an altered pattern of diastolic filling, with an elevation in intraventri...