Rapid Postpartum Glucose Normalization fails to Eliminate Long-Term Type 2 Diabetes Risk After GDM: Study

How quickly do glucose levels stabilize for mothers with gestational diabetes after delivery? A new study in BMC Pregnancy and Childbirth provides fresh insights into early postpartum glycemic patterns in women with gestational diabetes mellitus (GDM) compared to non-diabetic mothers.

Background: The Unanswered Question in GDM Management

GDM affects an estimated 17% of pregnancies worldwide and is linked to both short-term maternal risks and long-term risk for type 2 diabetes. Clinicians expect blood glucose to drop after birth due to the loss of diabetogenic placental hormones, but exactly how rapidly this normalization occurs—and how it compares to non-GDM mothers—has not been well characterized.

Study Design: Serial Glucose Monitoring in the Immediate Postpartum

This descriptive observational comparative study included 60 postpartum women—30 with GDM (diagnosed by 75g OGTT) and 30 without. Participants’ blood sugar was measured within 2 hours of delivery, then before and 2 hours after each main meal for 48 hours. Mothers with GDM were managed by dietary, oral, or insulin therapy; non-GDM mothers received standard hospital meals.

Findings: Early Hyperglycemia, Rapid Normalization

During the first 48 hours postpartum, mothers with GDM consistently had higher blood glucose levels than non-diabetic mothers, both before and after meals.

These differences were statistically significant at most early time points (e.g., 1st and 2nd pre- and postprandial values).

By the sixth meal (end of 48 hours), glucose levels between GDM and non-GDM groups converged, with no statistically significant difference—indicating a trend toward rapid normalization.

No significant difference in early postpartum glycemic patterns was seen between GDM mothers managed with metformin and those managed without.

Clinical Implications: What Should Clinicians Do?

The key takeaway for clinicians: While mothers with GDM show persistently higher glucose levels immediately after birth, most normalize by the sixth meal. However, early normalization does not mean the risk for future diabetes is resolved. The study reinforces the importance of routine postpartum glucose screening at 6 weeks and long-term follow-up, regardless of immediate postpartum readings.

Strengths and Limitations

Strengths include serial, structured glucose monitoring and comparable baseline characteristics. Limitations are a small sample size, single-center design, dietary differences between groups, and lack of biochemical markers such as insulin levels.

Conclusion:

Short-term glycemic normalization occurs rapidly in most GDM mothers postpartum, but ongoing risk for type 2 diabetes remains. Clinicians should continue to emphasize postpartum and long-term screening for all women with a history of GDM, regardless of initial glucose trends.

Key Points

Early postpartum hyperglycemia is common in mothers with GDM, but glucose levels typically normalize by the sixth meal.

Initial postpartum glucose spikes should not preclude standard 6-week and ongoing diabetes screening.

No difference was found in early normalization whether GDM was managed with or without metformin during pregnancy.

Routine, structured postpartum glucose monitoring can help guide early management but does not replace long-term surveillance.

Differences in diets and the single-center design may limit generalizability and should be considered when applying findings.

Citation:

Jayawardane MAMM, Rusta MMF, Gangodawila TH, Zainab MSR, Mallawarachchi MATU. Glycemic changes during first 48 h postpartum in mothers with gestational diabetes mellitus and non—diabetic mothers – a comparative study. BMC Pregnancy Childbirth (2026). https://doi.org/10.1186/s12884-026-09335-3