If you have gestational diabetes, your blood sugar is higher than normal during pregnancy, and both you and your baby will need closer monitoring until delivery. The good news: 75 to 80 percent of women with gestational diabetes manage their blood sugar through diet changes alone, and most go on to have healthy pregnancies. But untreated or poorly controlled gestational diabetes does carry real risks, so understanding what’s happening in your body and what to expect makes a significant difference.
Why It Develops
During pregnancy, the placenta produces hormones (including estrogen, cortisol, and human placental lactogen) that help sustain the pregnancy but also interfere with how your body uses insulin. This blocking effect typically kicks in around 20 to 24 weeks. As the placenta grows, it releases more of these hormones, and insulin resistance increases.
Normally, your pancreas compensates by producing extra insulin. Gestational diabetes develops when your pancreas can’t keep up with the demand. The result is blood sugar that stays too high, which affects both you and your baby. This is why screening usually happens between weeks 24 and 28, right when this hormone surge peaks.
How You’re Diagnosed
Most women are screened with a one-hour glucose challenge test. You drink a sugary solution and have your blood drawn an hour later. If your result is 140 mg/dL or higher, you’ll come back for a longer, fasting version of the test to confirm the diagnosis. Some women have no symptoms at all, which is why routine screening matters.
What It Means for Your Baby
When your blood sugar runs high, that extra glucose crosses the placenta and reaches your baby. The baby’s pancreas responds by producing more insulin to process all that sugar, and the excess energy gets stored as fat. This is what leads to macrosomia, the medical term for a baby that’s significantly larger than expected at birth.
A larger baby creates practical problems during delivery. The baby’s shoulders can get stuck in the birth canal (shoulder dystocia), which is one reason gestational diabetes increases the likelihood of needing a cesarean delivery. Beyond size, babies born to mothers with poorly controlled gestational diabetes face several other risks:
- Low blood sugar at birth. The baby’s pancreas has been making extra insulin throughout pregnancy. Once the cord is cut and the sugar supply stops, all that insulin can cause the baby’s blood sugar to drop sharply.
- Breathing difficulties. Babies born to mothers with gestational diabetes are more likely to have respiratory problems, especially if delivered early.
- Preterm birth or stillbirth. Uncontrolled blood sugar increases the risk of both.
- Long-term health effects. These children have a higher risk of developing obesity and type 2 diabetes later in life.
These risks are closely tied to how well blood sugar is controlled. That’s why management during pregnancy is so focused on keeping glucose levels in a tight range.
What It Means for You
Gestational diabetes raises your risk of preeclampsia, a serious pregnancy complication involving high blood pressure that can affect your organs. It also makes a cesarean delivery more likely, which means a longer recovery after birth.
The bigger concern is what happens after pregnancy. Having gestational diabetes is one of the strongest predictors of developing type 2 diabetes later in life. Both the American Diabetes Association and the American College of Obstetricians and Gynecologists recommend a glucose tolerance test 6 to 12 weeks after delivery to check whether your blood sugar has returned to normal. Even if it has, you’ll want to keep getting tested periodically in the years that follow.
How Blood Sugar Is Managed
The first line of treatment is changing what and how you eat. The goal is to keep your blood sugar steady throughout the day without sharp spikes after meals. Less than half your daily calories should come from carbohydrates, and keeping the amount and types of food consistent from day to day helps maintain that stability. You won’t be put on a starvation diet. You still need enough calories to support your pregnancy, but the focus shifts to spreading carbohydrates evenly across meals and snacks rather than eating large amounts at once.
Physical activity plays a supporting role. Walking is the most commonly recommended exercise because it’s accessible and low-impact, though swimming and similar activities work just as well. Even moderate movement after meals can help bring blood sugar down.
You’ll also be checking your blood sugar regularly, typically multiple times a day with a finger-prick monitor. Some providers now use continuous glucose monitors that track levels throughout the day. Your care team will use these numbers to decide whether diet and exercise are enough or whether you need additional help.
When Diet Alone Isn’t Enough
About 20 to 25 percent of women with gestational diabetes need medication to control their blood sugar. This usually means insulin injections, though some providers prescribe oral medications. Needing medication doesn’t mean you’ve failed. It simply means the hormonal resistance from your placenta is stronger than what lifestyle changes can overcome on their own. The medication is adjusted throughout pregnancy as your hormone levels change, and it stops after delivery.
What Delivery Looks Like
If your blood sugar is well controlled and your baby is growing normally, you can often carry to full term and deliver vaginally. Your provider will monitor your baby’s size with ultrasounds in the third trimester. If the baby is measuring very large, your provider may recommend inducing labor a bit early or scheduling a cesarean to reduce the risk of birth complications.
During labor, your blood sugar will be monitored closely. After birth, the medical team checks the baby’s blood sugar to catch any drops early. Most babies stabilize quickly, especially when feeding begins right away.
After Delivery
For most women, blood sugar returns to normal almost immediately once the placenta is delivered, since the hormones causing insulin resistance are no longer circulating. You’ll stop any diabetes medications, and the intensive blood sugar monitoring ends.
The follow-up glucose test at 6 to 12 weeks postpartum is important and often skipped. It’s the clearest window into whether the pregnancy unmasked a tendency toward type 2 diabetes that will persist. Even if that test comes back normal, the experience of gestational diabetes is a signal worth paying attention to. Maintaining a healthy weight, staying physically active, and getting screened for diabetes every one to three years are practical steps that meaningfully lower your long-term risk.