Table of contents

• Definition

• Risk factors

• Pathophysiology

• Screening

• Complications

• Congenital malformation

• Management

• Contraception

Definition

• GDM is defined as carbohydrate intolerance with onset/ first recognition during the present pregnancy.

Risk factors

• Age > 30 years

• Obesity

• Positive family history of diabetes

• H/O giving birth of a baby with a weight >4 kg

• Persistent glycosuria

• Previous stillbirth with pancreatic cell hyperplasia on pregnancy

• Polyhydramnios/ Recurrent vaginal candidiasis on pregnancy

• Unexplained perinatal loss.

Pathophysiology

• The hallmark of GDM is increased insulin resistance.

• Placental hormones and increased fat deposits during pregnancy, both seem to mediate insulin resistance during pregnancy.

• Although cortisol and progesterone are the main culprits; human placental lactogen, prolactin and estradiol also contribute.

Screening

DIPSI (Diabetes in pregnancy study group of India) recommends:

• As a pregnant woman walks into antenatal clinic in fasting state, she has to be given a 75 gm oral glucose load and after 2 hours, a venous blood sample is collected for estimating plasma glucose.

• A blood sugar > 140 mg/dl is gestational diabetes.

• This screening is recommended between 24-28 weeks of gestation.

Note:

75 gm glucose challenge test has the highest sensitivity for screening of gestational diabetes mellitus.

Complications of diabetes in pregnancy

Maternal Fetal Neonatal

Pre-eclampsiaPyelonephritis

PolyhydramniosPreterm labour

MacrosomiaSudden IUD

Shoulder dystocia

Metabolic disturbance: Hypoglycemia/ hypomagnesia/

hyperbilirubinemia/ hypocalcemiaBirth asphyxiaBirth injuries

Transient tachypnea

Congenital malformations in diabetes

• The most common congenital anomaly associated with gestational diabetes are cardiovascular anomalies.

• The most common cardiovascular anomaly in gestational diabetes is VSD.

• The most characteristic cardiovascular anomaly in gestational diabetes is TGA.

• The second most common congenital anomaly associated with gestational diabetes are neural tube defects (Ex.: anencephaly and spina bifida).

• The lesion characteristically associated with diabetic embryopathy is caudal regression syndrome/ sacral agenesis.

• Most useful test in 1st trimester to identify the risk of fetal malformation in a fetus of a diabetic mother is measurement of glycosylated Hb.

Management of GDM

Target:

Maintaining a mean plasma glucose (MPG) level ~105–110 mg/dL is desirable for a good fetal outcome.

This is possible if FPG and 2-hour PPBG are ~90 mg/dL and ~120 mg/dL, respectively.

Medical Nutrition Therapy (MNT)

• All women with GDM should receive nutritional counselling.

• The meal pattern should provide adequate calories and nutrients to meet the needs of pregnancy.

Initiating Insulin Therapy

• Once diagnosis is made, medical nutritional therapy (MNT) is advised initially for 2 weeks.

• If MNT fails to achieve control (FBG ~90 mg/dL and/or PPBG ~120 mg/dL), insulin may be initiated.

Continued….

• If GDM is diagnosed in the third trimester; MNT is advised for a week. Insulin is initiated if MNT fails.

• If 2-hour PPBG > 200 mg/dL at diagnosis, a starting dose of 8 units of Premixed insulin could be administered straightaway before breakfast and the dose has to be titrated on follow-up. Along with insulin therapy, MNT is also advised.

• If PPBG is still not under control— consider using rapid-acting insulin analogues.

Contraception in GDM

• Barrier method of contraceptives is ideal for spacing of births.

• Low dose combined oral pills containing third generation progestins, are effective and have got minimal effect on carbohydrate metabolism. Main worry is their effect on vascular disease (thromboembolism and myocardial infarction).

• Progestin only pill may be an alternative.

• IUCD may be used once diabetes is well controlled.

• Permanent sterilization is considered when family is completed.

Thank you