There has been an increasing number of researches comparing metformin with insulin in recent years. However, metformin’s usage in pregnant women is still debatable. The morbidity of gestational diabetes mellitus (GDM) has risen in recent years.
Based on the population examined and the diagnostic tests used, GDM complicates between 1–14 percent of all pregnancies. Any degree of glucose intolerance with onset or first identification during pregnancy has been defined. GDM, the most common medical complication of pregnancy, is linked to several negative short-term and long-term consequences for both mother and offspring. To begin with, the presence of GDM is always associated with an increased maternal risk of preeclampsia, cesarean section, and type 2 diabetes (T2D) following pregnancy.
Macrosomia and Diabetes
Excessive glucose transfer from the mother to the fetus also increases the risk of newborn mortality, stillbirth, and congenital abnormalities. Macrosomia, a risk factor for instrumental delivery, cesarean section, and shoulder dystocia during delivery, as well as neonatal hypoglycemia shortly after birth, is another obvious concern.
In addition, the effects of the intrauterine hyperglycemia environment may follow the offspring during adulthood. As a result, the primary goal of GDM therapy is to decrease the risk of poor pregnancy outcomes by managing glycemic levels.
When a proper diet, alone or in combination with physical activity, is insufficient to regulate blood glucose levels in pregnant women, subcutaneous insulin treatment has become the gold standard for GDM management.
Insulin and glycemic levels
Insulin, on the other hand, has several drawbacks, including the need for several daily injections, the danger of hypoglycemia, and maternal weight gain. It necessitates adjustments based on the patient’s BMI, glucose levels, and lifestyle. As a result, precise instructions for changing insulin doses are required to guarantee safe insulin self-administration.
Insulin, on the other hand, has some drawbacks, including the need for several daily injections, the danger of hypoglycemia, and maternal weight gain. It necessitates adjustments based on the patient’s BMI, glucose levels, and lifestyle.
As a result, precise instructions for changing insulin doses are required to guarantee safe insulin self-administration. Meanwhile, significant expenditures of health education on the proper use of insulin, as well as the cost of the medication, are being monitored. For women with GDM, effective and safe oral treatment would be more reasonable, though highly desired.
Metformin and glycemic levels
Consequently, understanding the impact of oral hypoglycemic medications on maternal and neonatal outcomes in women with GDM is critical. Metformin is on the considerable list as a first-line treatment for T2D. Metformin has not been widely utilized in GDM because it has a maternal-to-fetal transfer rate of 10–16 percent, which has been linked to fetal abnormalities and possible harmful effects on mothers and infants after delivery.
Pregnancy changes basal and postprandial glucose metabolism, there seems to be an increase in pancreatic B-cell response and hyperinsulinemia, which helps the fetus get glucose by shifting maternal energy metabolism from carbohydrate to lipids.
The production of placental hormones such as progesterone, placental lactogen, cortisol, growth hormone, and prolactin, on the other hand, causes an increase in insulin resistance. This resistance appears in the second trimester and continues until the placenta is delivered.
Many studies have found that metformin is similar to insulin in terms of glycemic management, as have earlier evaluations. Metformin lowers blood sugar levels by reducing hepatic glucose production (gluconeogenesis), improving insulin sensitivity, and boosting peripheral glucose absorption. When glucose management deteriorates due to increases in insulin resistance through pregnancy, these effects may be beneficial.
Furthermore, it is observed that the metformin group had considerably lower average postprandial hyperglycemia levels in the first week following randomization. This suggests that the metformin group met their glucose goals faster. The explanation for this might be that mastering the use and calculating insulin doses takes time for the individuals.
Many studies also show that, in the near term, metformin does not worsen newborn outcomes when compared to insulin. At the same time, the findings of research on metformin’s long-term effects are positive. At 6 months, neonates whose mothers took metformin had normal weight, social, and motor abilities, and there were no changes in height, weight, motor, or social skills between the neonatal groups at 18 months, according to research.
Furthermore, the findings of Rowan et al. This topic is both promising and comforting, raising the prospect of benefit in children and adolescents with intrauterine exposure to metformin.
Furthermore, there are potentially major advantages and dangers of metformin that have never been proven in maternal outcomes. One advantage is that it reduces maternal weight gain during pregnancy. Metformin reduces weight gain by inhibiting hepatic gluconeogenesis and glucose absorption and stimulating glucose uptake in peripheral tissues.
Obesity is usually associated with a higher risk of metabolic illnesses, therefore if you lose weight, you will face fewer difficulties. Another advantage of PIH is its decreased morbidity. Metformin’s complicated effects on endothelial functioning and reactive oxygen species generation may explain why it reduces endothelial activation and the maternal inflammatory reaction to insulin resistance.
Contrarily, even after excluding the data from the supplementary insulin group, average gestational ages at delivery were considerably lower in the metformin group, and the prevalence of preterm birth was significantly higher in the metformin group than in the insulin group. This suggests that metformin may have an unnoticed influence on the birthing process and that its usage during pregnancy should be carefully considered.
The different ethnic groups, research designs, and admission requirements may all contribute to heterogeneity in the outcomes of average fasting glycemic control and weight increase after enrolment. The varied gestational ages at enrolment may potentially contribute to weight gain variability.
Finally, because of the comparable glycemic control and neonatal outcomes, metformin might be utilized in women with GDM, especially those with moderate GDM. The risk of premature delivery, on the other hand, could not be overlooked. Clinicians should assess their options in practice based on the patient’s circumstances.
For various meals, metformin therapy can be linked to better postprandial glycemic control than insulin, reduced risk of hypoglycemia episodes, less maternal weight gain, and a low incidence of failure as an independent treatment. The majority of obstetrical and perinatal outcomes were comparable between groups.