Effect of tight glycaemic control on fetal complications in diabetic pregnancies.

AIMS: To find the incidence of fetal complications in Indian diabetic mothers with tight glycaemic control (TC), its comparison with other levels of glycaemic control, i.e., acceptable control (AC), uncontrolled (UC), and relevant international data.

METHODS: A total of 240 mothers with diabetes mellitus (DM) and pregnancy were risk-matched and selected from the Antenatal Clinic of NRS Medical College, 176 of whom had gestational diabetes mellitus (GDM) and 64 had pregestational diabetes mellitus (PGDM), and were put on exercise, diet and or insulin therapy. Glycaemic parameters monitored include fasting plasma glucose (FPG), 2 hr. postprandial plasma glucose (PPPG) and HbA1C. TC had - FPG < 70 mg/dl, PPPG < 100 mg/dl, HBA1C < 6.5%; AC with FPG 70-95 mg/dl, 2 hr. PPPG 100-120, HBA1C 6.5-7.5% and UC had FPG > 95 mg/ dl, 2 hr. PPPG > 120 mg/dl and HBA1C > 7.5%. Fetal parameters monitored included large-for-date babies (LGA), small-for-date babies (SFD), birth asphyxia, perinatal death, neonatal hypoglycemia, neonatal hypocalcaemia and congenital anomalies.

RESULTS: (i) LGA-AC had the best results (0% vs. 12.5 and 22.29%); (ii) SFD-TC and AC had worst results (16.7% and 18.18% vs. 0%); (iii) Birth asphyxia-AC fared worse 18.18% vs. 4.16% and 0%; (iv) perinatal death and congenital anomalies showed significant reduction with tight control (4.16% and 0% respectively); (v) Neonatal hypoglycemia is lowered in TC compared with UC while neonatal hypocalcaemia does not show any alteration. For PGDM patients there is little intra-group variability of the parameters. The UC subgroups of GDM fared better than PGDM as far as all complications and congenital anomalies were concerned. Compared with international data, there is a dichotomy of the results of GDM and PGDM.

CONCLUSION: For GDM patients all parameters may not be uniformly affected by the same degree of glycaemic control. A tight control may not be theonly factor to decide on the outcomes for PGDM patients.