Gestational diabetes mellitus (GDM) — a form of glucose intolerance that develops during pregnancy — is one of the more commonly discussed risk factors associated with pregnancy after age 35. Receiving a gestational diabetes diagnosis, or being told you’re at higher risk for it, can feel alarming, particularly on top of the other considerations that come with pregnancy later in life.
The reality is more nuanced than many women expect. Gestational diabetes is manageable in the large majority of cases, most women with GDM have healthy pregnancies and healthy babies, and understanding the condition clearly can help you engage with your care team from a place of informed participation rather than fear.
What Is Gestational Diabetes?
Gestational diabetes occurs when the hormones produced by the placenta during pregnancy impair the body’s ability to use insulin effectively — a phenomenon known as insulin resistance. When the pancreas is unable to keep up with the increased demand, blood sugar levels rise above what is considered safe for pregnancy.
According to the Centers for Disease Control and Prevention, gestational diabetes affects approximately 2–10% of pregnancies in the United States each year. Risk increases with maternal age, and women 35 and older face a statistically higher likelihood of developing GDM — though the majority of women in this age group do not develop it.
Risk Factors Beyond Age
Age is one of several factors associated with increased GDM risk:
- Pre-pregnancy BMI above 25: Higher body weight is consistently associated with increased insulin resistance.
- Personal history of GDM: Women who had GDM in a previous pregnancy have a significantly elevated risk of recurrence.
- Family history of type 2 diabetes: Genetic predisposition to insulin resistance increases GDM risk.
- Certain ethnic backgrounds: Higher rates of GDM are observed among women of South Asian, East Asian, Hispanic, and Black ancestry.
- Carrying multiples: Twin or higher-order pregnancies involve greater placental mass and hormonal output, increasing insulin resistance.
- Polycystic ovary syndrome (PCOS): PCOS is associated with underlying insulin resistance that may become clinically significant during pregnancy.
Conversely, women with none of these additional risk factors who are 35 may have a relatively modest elevation in GDM risk. Risk is rarely defined by a single factor in isolation.
How Gestational Diabetes Is Screened and Diagnosed
In the United States, most women are screened for GDM between 24 and 28 weeks of pregnancy. The most common screening approach uses a one-hour glucose challenge test (GCT) — a non-fasting test where you drink a glucose solution and have your blood drawn an hour later to measure blood sugar.
The Two-Step Approach
If the GCT result is above the screening threshold, a three-hour oral glucose tolerance test (OGTT) is typically performed under fasting conditions to confirm or rule out a diagnosis. A diagnosis of GDM is made if two or more of the four values meet or exceed established thresholds.
The One-Step Approach
Some providers use a two-hour OGTT as a single-step diagnostic test rather than a two-step process. Both approaches are clinically used and recognized; your provider can explain which approach is used in their practice and why.
Managing Gestational Diabetes
For most women with GDM, initial management involves monitoring blood glucose levels and making adjustments to diet and physical activity. A registered dietitian who specializes in gestational diabetes can be an invaluable resource for translating guidelines into practical meal planning.
Carbohydrate Awareness, Not Carbohydrate Elimination
Management of gestational diabetes does not typically mean eliminating carbohydrates, but rather understanding the quantity, quality, and distribution of carbohydrate-containing foods throughout the day. Research suggests that distributing carbohydrate intake across three moderate meals and two to three snacks tends to produce more stable glucose readings than large meals.
Physical Activity During Pregnancy With GDM
Moderate physical activity during pregnancy is generally associated with improved insulin sensitivity and can help with blood glucose management in women with GDM. Walking after meals, in particular, is often mentioned as a practical strategy that some women find helpful for reducing post-meal glucose spikes. Any changes to activity levels should be discussed with your OB/GYN.
Medication When Needed
When blood glucose levels cannot be maintained within the target range through diet and activity alone, medication — typically insulin or, less commonly, metformin — may be recommended. Insulin does not cross the placenta and is considered safe for use in pregnancy. Requiring medication to manage GDM does not indicate a more serious pregnancy complication in and of itself — it simply means that additional support for glucose control is needed.
For women also navigating the emotional aspects of a GDM diagnosis alongside other pregnancy concerns, resources on prenatal screening and pregnancy planning after 35 can provide additional practical context.
After Delivery: What Happens to GDM?
In the large majority of cases, gestational diabetes resolves after delivery, when the placental hormones that drove insulin resistance are no longer present. However, women who have had GDM are at approximately seven times the risk of developing type 2 diabetes later in life compared to those who did not have GDM. Postpartum glucose testing — typically at six to twelve weeks after delivery — is recommended to confirm that glucose levels have returned to normal.
Maintaining awareness of this longer-term risk and engaging in evidence-informed lifestyle practices — particularly regular physical activity and a balanced dietary pattern — is a meaningful form of preventive health investment for women in this group.
Frequently Asked Questions
Can I prevent gestational diabetes?
While there’s no guaranteed way to prevent GDM, research suggests that entering pregnancy at a healthy weight, engaging in regular physical activity, and eating a balanced diet with limited refined carbohydrates and added sugars may reduce the likelihood of developing it. These practices also support general health, making them worth prioritizing regardless of GDM risk.
Will gestational diabetes harm my baby?
Well-managed GDM is generally associated with healthy pregnancy outcomes. The risks associated with GDM — including macrosomia (a larger-than-average baby) and low blood sugar in the newborn — are primarily associated with poorly controlled blood glucose levels. Good glucose management, supported by your care team, significantly reduces these risks.
Does GDM mean I’ll need a C-section?
Not necessarily. Women with well-controlled GDM may deliver vaginally if there are no other contraindications. If the baby is significantly larger than average due to less well-controlled glucose levels, your provider may discuss mode of delivery. This is a conversation to have with your OB/GYN based on your specific circumstances as the pregnancy progresses.
How often should I check my blood sugar with GDM?
Monitoring frequency varies by provider and individual circumstances. A common protocol involves checking fasting glucose in the morning and glucose levels one or two hours after meals — typically four times daily. Your care team will provide specific targets and help interpret your readings over time.
Key Takeaways
- Gestational diabetes affects approximately 2–10% of pregnancies; risk is higher after 35 but is also influenced by many other factors including BMI, family history, and ethnicity.
- Most women with GDM have healthy pregnancies and babies; the condition is manageable, particularly when identified and addressed promptly.
- First-line management involves blood glucose monitoring and adjustments to diet and physical activity, often with support from a registered dietitian.
- Medication (typically insulin) may be needed when lifestyle measures alone don’t achieve adequate glucose control, and its use does not indicate a more serious complication.
- Women who have had GDM have an elevated lifetime risk of type 2 diabetes and benefit from ongoing monitoring and preventive health practices after pregnancy.
Medical Disclaimer
This content is for informational purposes only and does not constitute medical advice. Individual health situations vary significantly. Always consult a qualified healthcare provider before making decisions related to your health, fertility, or pregnancy.
About the Author
Emily Carter is a women’s health writer focused on fertility, pregnancy after 35, and sleep changes in midlife. She writes research-informed, non-alarmist content to help women navigate reproductive and hormonal transitions with clarity and confidence.