Papa Dasari
Dept of Obstetrics and Gynaecology, JIPMER, Puducherry, India

Abstract:

The conventional treatment of GDM is diet control and Insulin therapy when indicated. For advocating insulin therapy most often women need to get hospitalised for a prolonged period and the occurrence of hypoglycaemia also needs to be monitored carefully as hypoglycaemia is more dangerous to the fetus leading to sudden fetal demise. Oral hypoglycaemic agents during pregnancy were blamed to be associated with congenital malformations. Hence search is on for an oral agent which does not cause congenital malformations and does not lead to hypoglycaemia. Metformin is a Class B drug and hence it can be administered during pregnancy though it is not yet approved by FDA.

Objectives: This is a preliminary retrospective analysis undertaken with the objectives of assessing the glycaemic control in women with GDM who received metformin therapy and also to know the side-effects and affects on the fetus-neonate.

 Material and Methods: The maternal records of patients who received metformin for control of GDM were analysed with respect to the time of diagnosis (gestational age) of GDM and initiation of metformin therapy, the glycaemic control, the need to add insulin and the side-effects especially hypoglycaemia. Fetal outcome was also analysed which included  Apgar score at birth, birth weight, neonatal hypoglycaemia, still birth rate and congenital malformations and their nature. The goals of glycaemic control were achievement of a pre-prandial Blood sugar of 60-70 mg%; post prandial blood sugar of 120-140mg%.

Results:  The search revealed 38 women with GDM who received metformin for the past 6 yrs. The mean age was 27.5 years and gestational age at diagnosis was 24 weeks and 3 days.  Twenty four percent were diagnosed during first trimester and thirty four percent were diagnosed during the late third trimester. Twenty one percent suffered from hypothyroidism and thirteen percent suffered from recurrent pregnancy loss. Forty two percent were primigravidae.

Pregnancy outcome: Gestational hypertension developed in 23.7%. Most of them achieved glycaemic control with a dose of 1500 mg of metformin (given in 3 divided doses). Ten percent required increment in dose up to 2250 mg and addition of small dose of insulin only after 35 weeks of gestation. None of the women had hypoglycaemia or any other significant side effects resulting stoppage of metformin. The caesarean section rate was 50% and none of the neonates suffered from hypoglycaemia. The mean birth weight was 3.12 kg and 13% were LGA. There were no stillbirths, congenital anomalies or neonatal deaths in this series.

Conclusion:  Metformin therapy resulted in optimum control of blood sugar in most of the women with GDM without any significant side-effects in the mother or in the fetus-neonate.