tags:
- o&g/obsGDM (Gestational Diabetes Mellitus)
Carbohydrate intolerance of variable severity with onset or first recognition during the present pregnancy.
Previous GDM
First degree family h/o DM
Previous macrosomia/polyhydramnios
Multiple pregnancy
Obesity
Age ≥25 y/o
Normal metabolic changes during pregnancy:
Increase fetal demands after 18w -> increase carb intake to keep up with demands -> increase insulin requirements
Placental hCG opposes the action of insulin -> increase insulin resistance
Pancreatic beta cells work overtime to keep up with higher insulin demands
Eventually, pancreatic beta cells "tire out" and unable to keep up with insulin demands
Plasma glucose rises -> GDM
Bacteriuria - due to persistent glucosuria
Gestational HTN & Preeclampsia - insulin resistance of adrenal medulla -> increase catecholamine -> vasoconstriction
Hypomagnesemia - less Mg2+ is reabsorbed in the nephron due to glucose
IUGR - placenta cannot supply sufficient O2 & nutrients to the fetus
Preterm labour - placenta cannot support full term fetus
Hypocalcemia - reduced Mg2+ lvl results in reduce secretion of PTH
Macrosomia - increase exposure to glucose -> increase insulin production -> increase anabolic metabolism
Polyhydramnious
Shoulder dystocia
Neonatal RDS - insulin interferes with cortisol-induced fetal lung maturation
Perinatal asphyxia - baby's neck constricted in perineum
Neonatal jaundice - HTN mother -> episodic fetal hypoxia -> increase fetal erythropoietin -> increase RBC breakdown -> hyperbilirubinemia
When?
@booking for woman with risk factors.
@24-28w for age ≥25 with no risk factors.
How?
Fasting 8hrs
Take FPG
Drink 75g Dextrose + 250ml water
Wait 2hrs
Take 2-HPP plasma glucose
Results?
Normal: FPG ≤5.0
GDM: FPG ≥5.1 mmol/L OR 2-HPP ≥7.8 mmol/L
Overt DM: FPG ≥7.0 mmol/L
Diet control
Metformin
Insulin - Actrapid (short acting), Insulatard (intermediate acting)
Preeclampsia prophylaxis - Low dose aspirin
Detailed scan @18-20w
When?
With complications @37w0d
On MTF/Insulin @37w0d - 38w6d
Target CPG: 4.0-7.0 mmol/L
CPG 2-hourly in T2DM/GDM on medication
CPG 4-hourly in GDM on d/c
If T1DM or CPG >7.0 -> start IV insulin
Repeat CBG before transfer to ward & BSP at 24-48 hrs post delivery.
Repeat OGTT after 6w
Postpartum HbA1c
Annual diabetes screening
Advise - reduce weight, diet control & contraception
CNS & skeletal - sacral agenesis, neural tube defect, anencephaly, microcephaly, caudal regression syndrome
Cardiovascular - VSD, ASD, coarctation of aorta, transposition of great vessels, situs inversus, Fallot’s tetralogy
Renal - renal agenesis, hydronephrosis, double ureter, polycystic kidneys
GI - duodenal atresia, anorectal atresia, omphalocele, tracheoesophageal fistula
Other - single umbilical artery
CPG Malaysia (at least one of the following):
FPG ≥7.0 mmol/L
RPG ≥11.1 mmol/L with symptoms
*however, the diagnosis of overt DM is confirmed with a second test (FPG/RPG/OGTT)