Share on PinterestA new study investigated whether metformin could help pregnant people with gestational diabetes. Ryan J Lane/Getty Images
- A new study indicates that the medication metformin may benefit people with gestational diabetes.
- Metformin is a drug typically used to help treat type 2 diabetes but is not widely used for gestational diabetes because it crosses the placenta.
- Subjects who received metformin gained less weight throughout the study, and there was no evidence of increase in preterm birth.
- More research is needed to determine the safety of treating gestational diabetes with metformin.
A recent study investigated new methods to help manage gestational diabetes, which develops during pregnancy. Researchers from the University of Galway suggest that metformin may benefit pregnant people with the condition.
Metformin is a drug typically used to treat type 2 diabetes (T2D) but is not widely used for gestational diabetes because it crosses the placenta.
The results from the new study indicate that metformin, which is administered via an oral tablet, may be safely used to treat gestational diabetes and reduce the need for injection-administered insulin shots.
However, the researchers noted that the study, published October 3 in JAMA: the Journal of American Medical Association, was not designed to confirm the safety of metformin regarding specific outcomes.
“Metformin has been used for many years already with diabetes. It has been used for many years in gestational diabetes. But there were always questions about whether it is safe or not, or whether or not we should move right away to insulin,” said Dr. Eran Bornstein, Vice Chair of OB-GYN at Northwell Lenox Hill Hospital.
“This study is very reassuring because it shows women took metformin and had some benefits. It looks like it gives you a first glimpse that metformin may be associated with several improved outcomes.”
Treating gestational diabetes with metformin
The University of Galway study was a randomized, placebo-controlled trial that involved more than 500 pregnant females.
Subjects who were assigned metformin were 25% less likely to need insulin, and in the cases when insulin was necessary, it was started later in the pregnancy.
The study also found that women receiving metformin gained less weight throughout the trial and maintained this weight differently at the 12-week post-delivery visit. Delivery also occurred at the same mean gestational age in both groups, and there was no evidence of any increase in preterm birth among those who received metformin.
The study also showed no differences in adverse neonatal outcomes, such as the need for intensive care treatment for newborns, respiratory support, jaundice, congenital anomalies, birth injuries, or low sugar levels.
However, the study also showed that nearly 40% of women who were given metformin also needed to start insulin later in their pregnancy to better regulate their glucose levels.
This means insulin may still be part of the prescribed regimen during pregnancy for many patients who take metformin.
“This is a really interesting study because there have not been a lot of randomized controlled trials with placebos looking at the management of gestational diabetes,” said Dr. Meghana Limaye, maternal-fetal medicine specialist and clinical assistant professor in the Department of Obstetrics & Gynecology at NYU Langone Health.
How is gestational diabetes usually treated?
Gestational diabetes is a manageable condition. Through diet and lifestyle changes, many pregnant people successfully reverse their gestational diabetes before it develops into type 2 diabetes.
Regarding medication treatments for gestational diabetes, insulin is often the go-to.
The American Diabetes Association states that insulin is the traditional first-choice drug for blood glucose control during pregnancy because it is the most effective for fine-tuning blood glucose.
Insulin does not cross the placenta, which means it is safe for the developing baby.
“I like to use insulin for several reasons,” said Bornstein. “It’s safe, it’s safe for the baby, and it has years of experience with a good safety profile. It’s easy to titrate, as well. With a pill, you’re limited to the multiplication of the milligrams of a pill. With insulin, you can really titrate it.”
However, insulin is administered through injection. Many patients may prefer to avoid it because they want to avoid having to inject themselves sometimes multiple times per day.
“We have pregnant women check their sugars four times a day, which is pretty intensive,” said Limaye.
“They are able to monitor their food intake of sugary drinks, increase protein, and decrease carbohydrate intake to manage their diet alone. If sugars continue to be elevated, in order to decrease the risk of complications, we would recommend insulin.”
Future of gestational diabetes treatment
The study is a positive first step as a potential alternative to insulin, but experts are still waiting to see more studies in the future.
Limaye noted the study was small in scale and more research on the long-term impact on infants is still needed.
“The authors will be following the children and mothers to see what they do in the longer term. You need more babies exposed to metformin in order to evaluate,” Limaye said.
Bornstein added the takeaway is that it’s crucial to “perform screening for gestational diabetes in every pregnancy.”
“It’s important to individualize care with a specialized doctor. Some women may do well with dietary medication and exercise, and some may require assistance. For those who require assistance, starting metformin is a reasonable option,” Bornstein noted.
What to know about gestational diabetes
Gestational diabetes is a condition that affects nearly three million women around the world each year.
It’s a type of diabetes that can develop during pregnancy in women who do not already have diabetes.
According to the Centers for Disease Control and Prevention (CDC), 2 to 10% of pregnancies in the U.S. are affected by gestational diabetes each year.
It occurs when the body cannot make enough insulin during the pregnancy. Insulin is important for transferring blood sugar to the cells to be used as energy.
“Any woman is at risk for gestational diabetes,” said Limaye. “But some risk factors include being overweight, having a history of diabetes in the family, or having had gestational diabetes before.”
She added, “The main things associated with gestational diabetes are related to the fetus growing too large. It can be associated with birth complications, like increasing the rates of a C-section, hemorrhaging after delivery, or shoulder dystocia.”
The CDC notes other related health problems for the baby, including:
- preterm birth, which can cause breathing and other problems
- having low blood sugar
- developing type 2 diabetes later in life
There are no symptoms for gestational diabetes. Pregnant people will undergo blood glucose testing to be diagnosed.
A new study investigated whether metformin could help pregnant people with gestational diabetes.
The study found that women receiving metformin gained less weight throughout the trial and maintained this weight differently at the 12-week post-delivery visit.
Delivery occurred at the same mean gestational age in both groups, and there was no evidence of an increase in preterm birth among those who received metformin.