Infant of a Diabetic Mother
Frequency- 4% of pregnant woman have diabetes
88% have gestational diabetes
12 % known diabetics (35% type 1 and 65% type 2)
Pregnancy-risks
-White criteria
-Complications minimal with gestational diabetes vs. pregestational
diabetes
-Highest risk of birth defects in women with renal, cardiac or retinal disease
-Complications of diabetic pregnancies cause poor prognosis i.e.
Preeclampsia twice as common in diabetic pregnancies vs normal
pregnancies
Fetal Effects- increased insulin activity creates a metabolically abnormal
environment
6-7 th week- birth defects and spontaneous abortions
2nd/3rd trimester- macrodome and neonatal hypoglycemia
Diabetic fetopathy- intermittent maternal hyperglycemia causes fetal
hyperglycemia, which leads to premature maturation of fetal pancreatic islets,
resulting in hyperinsulinemia in the fetus
This causes:
1) macrosomia
2) fetal hyperinsulinemia increases metabolic rate which leads to increased
oxygen consumption and relative hypoxia in the fetus
fetal growth
-1st and 2nd trimester normal then in 3rd trimester larger abdominal girth and larger
organs, normal size head
fetal hypoxia
1) stimulates erythropoietin which causes polycythemia
2) promotes catecholamine production which leads to HTN and cardiac
hypertrophy
3) may contribute to 20-30% still birth rate in poorly controlled diabetics
Neonatal Effects (seen 0.6-4% of diabetic pregnancies)
Congenital Anomalies
2/3 are cardiovascular or CNS
anencephaly and spina bifida occur 12-20 more in IDMs than non-diabetic
mothers
common cardiac anomalies- transposition, VSD, coarc, ASD
GI, GU and skeletal anomalies are also seen- specific to IDM’s is small left
colon syndrome- inability to pass meconium that resolves spontaneously
Caudal Regression Syndrome- (caudal agenesis, sacral dysgenesis or caudal
dysplasia sequence) occurs 200 times more frequently in IDM than in regular
pregnancy. Spectrum of structural defects of the caudal region- incomplete
development of the sacrum and the lumbar vertebrae. Because of the
involvement of the distal spine- neurological impairment is involved- ranging from
incontinence to decreased growth and movement of the legs
Premature Delivery- spontaneous premature labor occurs more frequently
Perinatal Asphyxia- IDM are at higher risk for intrauterine or perinatal asphyxia
(low fetal hr, low apgars and intrauterine death)
Macrosomia- defined as >90% or >4000 grams. Typically appear large and
plethoric, with excess fat accumulation in abdominal and scapular regions, and
visceromegaly
-predisposes to birth injury, shoulder dystocia, brachial plexus palsy,
clavicular and humeral fractures, perinatal asphyxia and cephalohematoma
IUGR- IDM can be IUGR if poorly controlled diabetic (class F)
RDS- more frequent in infants of diabetic mom’s
-delayed maturation of surfactant synthesis caused by hyperinsulinemia
Other causes of Respiratory Distress-hypertrophic cardiomyopathy, and TTN
Metabolic complications
Hypoglycemia
<40 mg/dl (27% of IDM have hypoglycemia)
usually occurs in first few hours of life
occurs because of persistent hyperinsulinemia
Hypocalcemia
<7mg/dl
usually occurs in 24-72 hour of life
thought to be due to low PTH in infant which may be due to increased
maternal Ca during pregnancy
usually asymptomatic and resolves on its own
symptoms include- jitteriness, lethargy, apnea, tachypnea and seizures
routine screen not recommended
Hypomagnesemia
<1.5mg/dl
occurs in 40% of IDM
transient and asymptomatic
may need to treat if hypocalcemic
Polycythemia and hyperviscosity
Central crit>65
Occurs in 13-33% of IDM
Related to hypoxia inutero
Hyperviscsity- may lead to sludging and ischemia and infaction of internal
organs
Hyperbilirubinemia
11-29% in IDM
thought to be due to increased hemolysis
Cardiomyopathy
Most are asymptomatic, but 5-10% have respiratory distress or signs of
poor cardiac output or heart failure
Usually transient but needs to be supported
ECHO resolves in 6 months
Thought to be due to fetal hyperinsulinemia, which increases synthesis and
fat deposition in myocardial cells