Many women DO NOT have Diabetes before pregnancy. Some may have Diabetes before pregnancy but it was UNDIAGNOSED. If these women develop Diabetes in pregnancy or it is detected for the first time in pregnancy, then it is called GESTATIONAL DIABETES MELLITUS (GDM). 

Why GDM is so important?

GDM carries risk to the mother and baby, both during pregnancy and thereafter.

Risks for the baby before birth:

  • Increased risk of birth defects (especially in the heart, brain and spine). High blood sugar level in early pregnancy increases the risk. 
  • Increased risk of spontaneous miscarriage.
  • Sudden "Unexplained" DEATH of the baby inside the uterus. It can happen when blood sugar is very high but all reports like ultrasound are Absolutely NORMAL. 
  • Excessive Growth of the baby or Inadequate Growth.
  • Premature Delivery.

Risks for the baby after birth:

  • Increased chance of breathing troubles, infection, feeding problems, low blood sugar and jaundice.
  • Increased risk of birth trauma (injury to shoulder, nerves, brain)
  • Increased chance of requiring NICU Admission.
  • Increased risk of developing Diabetes, Obesity and Cardiac Disease in later life.

Risks for the mother during pregnancy:

  • Increased risk of Preeclampsia (high BP and leakage of protein in urine).
  • Increased risk of infection and bleeding. 
  • Increased chance of requiring Caesarean Section or Instrumental Delivery (Forceps, Vacuum).

Risks for the mother after pregnancy:

50% of the women, who develop GDM, will develop Diabetes and Cardiac diseases in later life.

Which women are at risk of developing GDM?

Women, who are obese, age more than 35 years or having family history of Diabetes, are at higher risk of developing GDM. But ethnically, all women from South Asia are prone to develop GDM. 

How to check for GDM?

Conventional Fasting (FBS) and Post-Prandinal (PPBS) sugar are of little value in detecting GDM. 

The ideal test is OGTT (Oral Glucose Tolerance Test) done by drawing blood exactly 2 hours after taking 75 gram glucose orally. If the value is more than 140 mg/dl, it is called GDM. If a woman's baby died before birth in previous pregnancy, in next pregnancy, OGTT must be done. 

All International Bodies are recommending Routine OGTT for women at high risk of developing GDM. The DIPSI (Diabetes in Pregnancy Study Group in India) has recommended that all the India women should have OGTT at least 2 times in pregnancy-

  1. In early pregnancy
  2. Around 24-28 weeks of pregnancy

What to do if GDM is diagnosed?

The first line of treatment is dietary modification. If it fails to control sugar properly, Insulin may be added. In some cases, oral medicines like Metformin can be used safely. The blood sugar should be monitored regularly. The target fasting sugar must be below 100 mg/dl and the PP sugar below 120 mg/dl.

Routine pregnancy tests (Combined test around 11-13 weeks and Anomaly Scan around 18-20 weeks) should be done. In addition, Fetal Echocardiography (to see any abnormalities in the baby's heart) should be done at 20-22 weeks. Growth Scan and Colour Doppler should be done regularly (every 2-4 weeks) from 28-30 weeks.

If everything is fine, delivery should be done around 37-38 weeks. Steroid Injection should be given to the mother to reduce the risk of breathing problem of the baby. Delivery must be done at NICU set up (to manage any problems of the baby). 

Mother should check her blood sugar at least annually throughout the life.

Case study

This lady came to us in her 4th pregnancy. All previous pregnancies were uncomplicated and there were normal delivery. Her age is 36 years. We performed OGTT and diagnosed GDM. It was well controlled with diet and oral medicines. All tests like Combined test, Anomaly Scan, Fetal Echocardiography, Growth Scan were done. Steroid was given. But as the baby's weight was larger, delivery was done by Caesarean Section at NICU set up. Baby's birth weight 3.6 kg, but did not require NICU. Now mother and baby both are healthy.