About 4 percent of pregnant women in the United States - or about 135,000 women a year - are affected by gestational diabetes, according to the American Diabetes Association.
(Women diagnosed with gestational diabetes have not had diabetes before but have high blood sugar levels during pregnancy.)
Although gestational diabetes typically goes away after a woman delivers her baby, it poses significant health risks for the baby during pregnancy, says Dr. Mary Jo Johnson, chief of obstetrics at St. Joseph Medical Center.
Who is at risk for gestational diabetes?
Any pregnant woman is at risk for gestational diabetes, but some women are at higher risk. The higher-risk folks are women who are older, have had multiple gestations, obese women and women of certain ethnic groups such as Hispanic, African-American or American Indian.
What causes gestational diabetes?
The placenta in pregnancy makes anti-insulin factors that fight our own body's ability to handle sugar during pregnancy. This seems to peak in the late second trimester, so we typically screen for diabetes between 24 and 28 weeks of pregnancy.
What is the role of insulin in the body?
Insulin is the hormone made by the pancreas that allows us to metabolize [glucose]. ... But the interesting thing about insulin in the fetus is that it acts as a growth factor.
What effect does gestational diabetes have on the mother?
If the mother has gestational diabetes, it usually is resolved after birth. But what we are finding is that more and more women are being diagnosed during pregnancy - and that many of those being diagnosed actually have diabetes that no one knew about. Our routine screenings during pregnancy are picking the diabetes up. What affect does gestational diabetes have on the fetus?
The biggest complication of gestational diabetes is macrosomia - or babies being born big. If the mother has gestational diabetes and is not able to use insulin effectively, glucose builds up, and the higher levels of glucose cross over the placenta to the fetus.
The fetus is not diabetic and so produces more insulin to use up all the glucose that is coming over. That insulin acts as a growth factor in the fetus. And what we see is babies with big heads and big shoulders. These larger babies can suffer injuries during delivery because of this size.
Do these larger babies stay bigger as they grow up?
We are beginning to feel these obese babies are at higher risk for [Type II] diabetes themselves and, ultimately, all the complications of obesity.
Can anything be done to prevent gestational diabetes?
If it is the mom's first pregnancy, and she is diagnosed with gestational diabetes, then nothing can be done about it - she has been diagnosed. But when she has a second child, weight loss [before pregnancy] can help.
Once a diagnosis is made, what is the treatment?
We take a multidisciplinary attack. The first stop is the dietitian who talks to the moms about balancing their calories over the day. Rather than three big meals a day, they eat three smaller meals and three snacks. Some women can control their gestational diabetes with diet alone.
A diabetes educator will collect background data to see if they may have underlying diabetes. We teach them how to use a glucometer, and the moms check their blood sugar four times a day.
What else does the treatment include?
Let's say we have a mom who has done all that [described above] and her blood sugar looks fine, and the baby is growing normally; we may keep her on the diet and keep checking the baby. If the blood sugar stays high, we can use an oral pill or put her on insulin.
What if the baby is not growing normally?
If the baby is already big, we will move to put the moms on insulin. At 30 to 32 weeks, we have time to intervene with the macrosomic babies so they won't be 9-, 10-, 11-pounders. That is the good thing about screening at 24 weeks.
What do you say to your patients if they are diagnosed with gestational diabetes?
What I tell my moms is if you don't have underlying diabetes, gestational diabetes is not that much of a problem as far as the mom goes: It really is all about the baby. For the babies, besides having the risk of injuries at delivery, it means being at risk for metabolic issues, neonatal jaundice and blood-sugar abnormalities. We are talking about trying to get healthy babies who go home with Mom. That is what the work with gestational diabetes is all about.