Obstetrics

Diabetes Mellitus in Pregnancy

High-Yield Guide

Pharmacology of Obstetrics

Diabetes in pregnancy (pre-gestational or GDM) increases risks of congenital anomalies, macrosomia, and stillbirth. Tight glucose control is critical.

Types & Pathophysiology

Pregnancy → insulin resistance (hPL, progesterone)

GDM: beta-cell failure → hyperglycemia → fetal hyperinsulinemia

Fetal Risks

Risk Mechanism
Malformations1st trimester hyperglycemia
MacrosomiaFetal hyperinsulinemia
Neonatal hypoglycemiaHyperinsulinemia
StillbirthPlacental insufficiency

Screening

  • 24–28 weeks: 75g OGTT
  • Early screening if high-risk

Management

Goals

  • Fasting <95 mg/dL
  • 1h PP <140, 2h <120

Treatment

  • Diet + exercise
  • Insulin (gold standard)
  • Metformin/glyburide (selected cases)

Delivery & Postpartum

  • Delivery ~38 weeks (pre-gestational)
  • IV insulin + glucose in labor
  • Postpartum OGTT at 6–12 weeks

Key Takeaways

  • GDM → 50% risk of T2DM later
  • Insulin does not cross placenta
  • Target: fasting <95, 2h PP <120
  • Screen all at 24–28w
  • Macrosomia → cesarean if EFW >4500g

Conclusion

Diabetes in pregnancy is manageable with tight control. Every glucose reading counts.

Diabetes in pregnancy is a marathon — control wins.