Diabetes in Pregnancy

On this page

Diabetes in Pregnancy - Sweet Beginnings

  • Encompasses Pre-gestational Diabetes (PGDM) & Gestational Diabetes Mellitus (GDM).
  • GDM: Glucose intolerance first detected during pregnancy.
    • Screening (India - DIPSI): Single 75g OGTT; 2-hr plasma glucose $\ge$ 140 mg/dL.
    • Diagnosis (WHO criteria): 75g OGTT; any one: Fasting $\ge$ 92, 1-hr $\ge$ 180, 2-hr $\ge$ 153 mg/dL.
  • PGDM: Pre-existing Type 1 or Type 2 DM; higher congenital anomaly risk.
  • Key risks: Macrosomia, neonatal hypoglycemia, preeclampsia, future maternal T2DM.

⭐ GDM typically manifests in the 2nd/3rd trimester due to placental hormones (e.g., hPL) inducing insulin resistance.

Diabetes in Pregnancy - Insulin's Uphill Battle

  • Pregnancy: A diabetogenic state due to placental hormones.
    • Key antagonists: Human Placental Lactogen (hPL), progesterone, estrogen, cortisol.
    • These ↑, causing progressive ↑ insulin resistance, peaking in late pregnancy.
  • Pancreatic β-cells ↑ insulin production to compensate (hyperinsulinemia).
  • GDM: Develops if β-cells fail to overcome this resistance.
    • Pre-existing DM: Control often worsens. Hormonal basis of insulin resistance in pregnancy

⭐ Human Placental Lactogen (hPL) is a major contributor to insulin resistance during pregnancy.

Diabetes in Pregnancy - Catch & Confirm

  • Universal GDM screening is crucial.
  • Indian Guidelines:
    • DIPSI (Single Step): Non-fasting 75g Oral Glucose Tolerance Test (OGTT).
      • 2-hour Plasma Glucose (PG) ≥ 140 mg/dL → GDM.
    • IADPSG/WHO (One Step): Fasting 75g OGTT.
      • Any one value met/exceeded: Fasting PG (FPG) ≥ 92 mg/dL, 1-hour PG ≥ 180 mg/dL, 2-hour PG ≥ 153 mg/dL → GDM.
  • Overt Diabetes (Pre-existing): FPG ≥ 126 mg/dL, HbA1c ≥ 6.5%, or Random PG (RPG) ≥ 200 mg/dL with symptoms.

⭐ GDM diagnosis by IADPSG criteria is associated with a significantly increased risk of Large for Gestational Age (LGA) infants compared to older criteria.

Diabetes in Pregnancy - Mom & Baby Woes

Maternal Complications:

  • Pre-eclampsia, eclampsia: ↑ risk
  • Infections: UTI, candidiasis common
  • Polyhydramnios: Due to fetal polyuria
  • Operative delivery: ↑ C-section rates
  • Diabetic Ketoacidosis (DKA): Life-threatening
  • Progression of microvascular disease (retinopathy, nephropathy)

Fetal & Neonatal Complications:

  • Macrosomia (>4-4.5 kg)
    • Leads to birth trauma (e.g., shoulder dystocia)
  • Neonatal Metabolic Issues:
    • Hypoglycemia (due to fetal hyperinsulinemia)
    • Hypocalcemia, Hypomagnesemia
  • Respiratory Distress Syndrome (RDS): Delayed lung maturity
  • Hyperbilirubinemia, Polycythemia
  • Congenital Malformations (esp. with pre-GDM):
    • Cardiac (VSD, TGA), CNS (NTDs)

    ⭐ Caudal regression syndrome is a rare but highly specific congenital anomaly associated with pre-gestational maternal diabetes.

  • Stillbirth: Increased risk with poor glycemic control

Diabetes in Pregnancy - Sweet Control

  • Goal: Euglycemia (Fasting <95 mg/dL, 1hr PP <140 mg/dL, 2hr PP <120 mg/dL).
  • Management Steps:
    • Medical Nutrition Therapy (MNT) & Exercise: First line.
    • Pharmacological: If MNT fails.
      • Insulin: Preferred. (📌 Insulin Is Ideal)
      • Oral Hypoglycemics (OHAs): Metformin, Glyburide (cautious use).
  • Monitoring: Self-monitoring of blood glucose (SMBG) 4-6 times/day.
  • Intrapartum: Maintain glucose 80-110 mg/dL.
  • Postpartum: Screen for overt diabetes at 6-12 weeks.

⭐ Oral Glucose Tolerance Test (OGTT) with 75g glucose is the standard for postpartum screening for diabetes after GDM.

High‑Yield Points - ⚡ Biggest Takeaways

  • Screen GDM: 24-28 weeks with 75g OGTT.
  • GDM diagnosis (75g OGTT): Fasting ≥92, 1-hr ≥180, 2-hr ≥153 mg/dL (any one).
  • hPL: Main diabetogenic hormone, causes insulin resistance.
  • Macrosomia (>4kg) is key fetal risk; shoulder dystocia ↑.
  • Congenital anomalies (sacral agenesis) in pre-existing DM, not GDM.
  • Insulin: First-line for GDM if diet fails; Metformin oral option.
  • Postpartum: Screen for diabetes at 6-12 weeks with 75g OGTT.

Practice Questions: Diabetes in Pregnancy

Test your understanding with these related questions

A baby born at 34 weeks gestation weighs 3kg. Which of the following conditions is this child most likely to develop in the immediate postnatal period?

1 of 5

Flashcards: Diabetes in Pregnancy

1/10

Is GDM associated with malformations?_____

TAP TO REVEAL ANSWER

Is GDM associated with malformations?_____

No

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial