Fetal cardiac effects of maternal hyperglycemia during pregnancy

Abstract

Maternal diabetes mellitus is associated with increased teratogenesis, which can occur in pregestational type 1 and type 2 diabetes. Cardiac defects and with neural tube defects are the most common malformations observed in fetuses of pregestational diabetic mothers. The exact mechanism by which diabetes exerts its teratogenic effects and induces embryonic malformations is unclear. Whereas the sequelae of maternal pregestational diabetes, such as modulating insulin levels, altered fat levels, and increased reactive oxygen species, may play a role in fetal damage during diabetic pregnancy, hyperglycemia is thought to be the primary teratogen, causing particularly adverse effects on cardiovascular development. Fetal cardiac defects are associated with raised maternal glycosylated hemoglobin levels and are up to five times more likely in infants of mothers with pregestational diabetes compared with those without diabetes. The resulting anomalies are varied and include transposition of the great arteries, mitral and pulmonary atresia, double outlet of the right ventricle, tetralogy of Fallot, and fetal cardiomyopathy.A wide variety of rodent models have been used to study diabetic teratogenesis. Both genetic and chemically induced models of type 1 and 2 diabetes have been used to examine the effects of hyperglycemia on fetal development. Factors such as genetic background as well as confounding variables such as obesity appear to influence the severity of fetal abnormalities in mice. In this review, we will summarize recent data on fetal cardiac effects from human pregestational diabetic mothers, as well as the most relevant findings in rodent models of diabetic cardiac teratogenesis.

Maternal Gestational Diabetes and Fetal Congenital Heart Disease: An Observational Study

“…Fetal exposure to hyperglycaemia during embryogenesis, in women with poorly controlled diabetes mellitus, is known to be associated with congenital abnormalities, including congenital heart disease (CHD) [2,4,8,17]. A small increase in circulating blood glucose levels may be detrimental to the developing embryo and good glycaemic control has been shown to reduce the rate of congenital abnormalities, preterm delivery and stillbirths [18][19][20].…”

Pattern of Babies With Congenital Malformations Admitted in a Tertiary Newborn Care Unit

“…Studies have shown conclusively that maternal hyperglycemia is associated with an increased risk of mal development in the conceptus, specially neural tube and cardiac defects though the exact mechanism is not known. 6,7 Central nervous system and Gastro intestinal system including orofacial group were the most commonly involved. 8 the neural tube defects predominate in the central nervous system anomalies; the most common being meningomyelocele.…”

Random Blood Glucose Levels Among Pregnant Women Attending Ante-Natal Clinic in Ahmadu Bello University Teaching Hospital, Shika-Zaria, Nigeria.

“…14 The human chorionic gonadotropin (hCG) secreted by the corpus luteum of pregnancy, progesterone, relaxin and human chorionic somatomammotropin (hCS) secreted by syncytiotrophoblast all increases to maintain the possible changes in pregnancy. 8,10 During first and early second trimesters of pregnancy, glucose tolerance is normal or slightly improved and peripheral (muscle) sensitivity to insulin and hepatic basal glucose production is normal. 7,9 These could be caused by the increased maternal estrogen and progesterone in early pregnancy which increase and promote pancreatic ß-cell hyperplasia (Expansion of betacell mass in response to pregnancy) causing an increased insulin release.…”

“…38,40 The most notable cardiac defects are transposition of the great arteries, mitral and pulmonary atresia, double outlet of the right ventricle, tetralogy of Fallot, and fetal cardiomyopathy. 10,25 Hyperglycemia during pregnancy can result in gestational diabetes in women with borderline or low pancreatic function. [26][27] Gestational diabetes has been associated with obstetric and neonatal problems and usually occurs in the later stages of pregnancy, that is late second and third trimester.…”