recent posts

DIABETES MELLITUS IN PREGANACY

image
Incidence

  • 2-3% of pregnancies are complicated by diabetes mellitus

Normal Physiology in Pregnancy 
  1. in early pregnancy (T1) insulin secretion is increased and its anabolic
    actions are potentiated, decreasing fasting maternal glucose levels and
    promoting maternal energy storage
  2. in later pregnancy (T2,T3) insulin resistance develops  due to anti-insulin factors: human placental lactogen (increased secretion with
    growth of the placenta) and cortisol
  3. result: higher fasting glucose and enhanced lipolysis (increased FFA,TG, lipids, ketones) to supply energy for fetal growth

Classification of Diabetes Mellitus (DM)

  1. Insulin Dependent DM (Type I)
  2. Non-Insulin Dependent DM (Type II)
  3. Gestational Diabetes: DM diagnosed during pregnancy
Complications of Pregnancy in the Diabetic

  • Maternal
  1. hypertension/PET, polyhydramnios, pyelonephritis/UTI
  2. ketoacidosis, diabetic coma, worsening retinopathy in Type I or Type II, NOT in GDM

  • Fetal
  1. maternal hyperglycemia leads to fetal hyperinsulinism : accelerated anabolism and macrosomia result
  2. increased congenital anomalies and miscarriage from preconception or T1 hyperglycemia
  3. cardiac (VSD), neural tube, genitourinary, gastrointestinal and MSK (sacral agenesis) defects
  4. IUGR if mother has end-organ damage
  5. delayed fetal lung maturity
  6. preterm labour/prematurity
  7. increased incidence of stillbirth

  8. pregnancies complicated by GESTATIONAL diabetes do not manifest an increased risk of congenital anomalies because it develops later (i.e. after T1)
  • Neonatal
  • macrosomia and associated birth trauma, hypoglycemia, hyperbilirubinemia and jaundice, hypocalcemia, polycythemia, and RDS

Treatment of DM in Pregnancy

T1

  1. see prior to pregnancy to optimize glycemic control (will reduce risk of congenital anomalies)
  2. since oral hypoglycemics are contraindicated, Type IIís must be switched to insulin
  3. counsel : potential complications and risks
  4. advise preconception folic acid
  5. see early and date pregnancy
  6. consult internist and dietitian to manage insulin and diet
  7. measure hemoglobin A 1C early in T1 or preconception if possible; this gives an indication of glycemic control during embryogenesis and can be used to estimate risk of birth defects
  8. initial evaluations: 24 hour urine (protein and creatinine clearance), retinal exam, ECG, urine C&S, hemoglobin A 1C
  9. throughout pregnancy monitor BP, urine dip (protein/glucose/ketones), weight gain, blood glucose (self-monitor) every visit and occasional urine C&S and hemoglobin A1 C
  10. in early pregnancy transfer of glucose and amino acids to the fetus results in a tendency toward maternal hypoglycemia
  11. nausea and vomiting may reduce food intake, therefore may need to decrease insulin dose
T2
  1. clinic visits  2 weekly
  2. MSAFP (at 16 weeks) and 3 detailed U/S examinations
  3. consider fetal echocardiography to exclude congenital heart  defect
  4. admit for blood sugar control if needed
  5. in the second half of pregnancy, the diabetogenic action of placental hormones outweigh the continuous siphoning of  glucose by the fetus
  6. demand for insulin is increased, hence insulin dosages need to be increased
T3

  1. clinic visits  weekly
  2. fetal surveillance (BPP, NST); frequency depends on risk

    • < 36 weeks = weekly
    • > 36 weeks = weekly or biweekly

  3. timing of delivery dependent upon fetal and maternal risk factors
  4. can wait for spontaneous labour if glucose well-controlled and BPP normal
  5. induce by 40 weeks

Labor
  1. increased risk of CPD (Cephalopelvic Disproportion), shoulder dystocia with babies weighing over 4000 g
  2. elective C-section for predicted birth weights of greater than 4500 g (controversial)
  3. during labour monitor sugars 1h with patient on insulin and dextrose drip and aim for blood sugar of 3.5 to 6.5 to reduce the risk of neonatal hypoglycemia

Postpartum
  1. increased risk of hypoglycemia
  2. once eating a regular diet, resume insulin at two-thirds of prepregnancy dose and monitor 6 hourly
DIABETES MELLITUS IN PREGANACY DIABETES MELLITUS IN PREGANACY Reviewed by Radiology Madeeasy on January 13, 2011 Rating: 5
Powered by Blogger.