PATHOPHYSIOLOGY OF GESTATIONAL DIABETES MELLITUS

HORMONES INVOLVING THE OCCURRENCE OF GDM

RISK FACTORS

A previous diagnosis of gestational diabetes or pre diabetes, impaired glucose tolerance, or impaired fasting glycaemia

A family history revealing a first degree relative with type 2 diabetes

Maternal age - a woman's risk factor increases the older she is (especially if older than 35 years of age)Being overweight, obese or severely obese increases the risk by a factor 2.1, 3.6 and 8.6, respectively.

Previous pregnancy which resulted in a childwith a high birth weight (>90th centile, or >4000g)

Previous poor obstetric historyMATERNALCOMPLICATIONS

Increased risk for Caesarean Delivery

Higher risk of Preeclampsia

Diabetic ketoacidosis

Coronary Artery Disease

Nephropathy

RetinopathyFETAL COMPLICATIONS

Large for gestational age (macrosomic)

Macrosomia in turn increases the risk of instrumental deliveries (e.g. forceps, ventouse and caesarean section)

Problems during vaginal delivery (such as shoulder dystocia).

Neonates are also at an increased risk of low blood glucose (hypoglycemia), jaundice, high red blood cell mass (polycythemia) and low blood calcium (hypocalcemia) and magnesium(hypomagnesemia)

POTENTIAL CONGENITAL FETALANOMALIES

1.CNS: spina bifida, anencephaly, holoprosencephaly, hydrocephalus

2.Cardiac (most common): transposition of the great vessels ,ventricular septal defect, atrial septal defect, hypoplastic left heart, cardiac hypertrophy, anomalies of the aorta

3.GI: trachea esophageal fistula, anal/rectal atresia

4.Genitourinary: renal agenesis, double ureter, cystic kidneys

5.Skeletal: caudal regression syndrome (most specific)

6.Situs inversus

GDM also interferes with maturation , causing dysmature babies prone to respiratory distress syndrome due to incomplete lung maturation