Redefining Diabetes Care in Pregnancy

New Endocrine Society and European Endocrine Society guidelines provide a much-needed update

Making its debut at ENDO 2025, “Diabetes and Pregnancy: An Endocrine Society and European Society of Endocrinology Joint Clinical Practice Guideline” has been long anticipated. For the first time, clinicians will have a definitive guide on treating these patients that now includes the most recent technological breakthroughs in diabetes treatments.

Making its much-anticipated debut at ENDO 2025 in San Francisco, the Endocrine Society’s new clinical practice guidelines on diabetes and pregnancy represent a watershed moment for endocrinologists and specialists in maternal–fetal medicine.

The guidelines arrive at a pivotal time when both type 1 and type 2 diabetes as well as gestational diabetes (GDM) rates are surging among women of reproductive age, offering clinicians contemporary, evidence-based recommendations that address the latest technologic advances and therapeutic developments in diabetes care. “Diabetes and Pregnancy: An Endocrine Society and European Society of Endocrinology Joint Clinical Practice Guideline” aims to dramatically improve outcomes for mothers with preexisting diabetes and their infants.

Why now? “The last Endocrine Society Guidelines for Diabetes and Pregnancy were published more than a decade ago,” explains guideline first author Jennifer Wyckoff, MD, of the University of Michigan in Ann Arbor, Mich. “Advances in glucose monitoring, insulin delivery, and new medications have occurred in that time, which have changed the standard of care for diabetes outside of pregnancy significantly. These guidelines seek to provide direction on how these new advances in diabetes care apply in the setting of pregnancy as well as to review new data which reinforce some of the previous recommendations.”

With rates of type 1 and type 2 diabetes having doubled from 1990 to 2020 (National Institutes of Health) and that of GDM increasing from 6.0% to 8.3% from 2016 to 2021 (U.S. Centers for Disease Control and Prevention), the need for disseminating these clinical updates is clear. Coauthor Annunziata Lapolla, MD, of the University of Padova, Italy, says, “Obesity, hypertension, and other diabetes complications determine risks of adverse outcomes of pregnancy. So it is strongly necessary to provide recommendations for the care of individuals with preexisting diabetes in order to reduce maternal and neonatal adverse outcomes.”

Both Wyckoff and Lapolla are longtime experts in the field and look forward to sharing the new guidelines at ENDO 2025.

GRADE Methodology and Guideline Development

Importantly, the new guidelines were created based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology recently embraced by the Endocrine Society to assess the certainty of evidence and guide recommendations. GRADE also incorporates perspectives from patient representatives and considers patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. This two-pronged approach pairs the highest level of scientific rigor with patient lived experience to ensure that a broader range of patient needs are being met.

While previous guidelines were certainly also carefully researched and thoughtfully delivered, GRADE demands more focused parameters. “Previous Endocrine Society guidelines were comprehensive recommendations for an area of clinical practice,” Wyckoff notes. “More recently, the Endocrine Society has opted for evidenced-based guidelines, based on strict GRADE methodology supported by metanalyses, if possible, to provide in-depth understanding of a number of key questions in a specific area.”

“Advances in glucose monitoring, insulin delivery, and new medications have occurred in that time, which have changed the standard of care for diabetes outside of pregnancy significantly. These guidelines seek to provide direction on how these new advances in diabetes care apply in the setting of pregnancy as well as to review new data which reinforce some of the previous recommendations.” –  Jennifer Wyckoff, MD, University of Michigan, Ann Arbor, Mich.

As such, a Guideline Development Panel (GDP) of a multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, came together to identify the 10 most important clinical questions related to the care of individuals with preexisting diabetes before, during, and after pregnancy. To provide the best answers possible to these 10 questions, the GDP combed the available research, prioritizing randomized, controlled trials (RCTs) from which to extract the most thoroughly investigated findings.

Summary of the Recommendations

The 10 clinical questions centered on preconception planning (PCC), technology, glucometrics, delivery timing, medications, and diet.

Preconception Imperative. First and foremost, the new guidelines for diabetes in pregnancy recommend that clinicians ask about pregnancy plans at every visit and advise using contraception until pregnancy is desired.

“There is clear evidence in women with preexisting diabetes that PCC, which includes achieving strict glycemic goals, reduces the risk of congenital malformations and other adverse pregnancy outcomes,” states Lapolla. “However, only a minority of women receive PCC.”

Glucometrics and Technology. Of course, in any patient with diabetes, glucose monitoring is critical, so several questions looked at how this is best achieved in various pregnancy settings. The guidelines make a key recommendation against replacing traditional blood glucose targets with a single continuous glucose monitoring (CGM) target range of 63 mg/dL to 140 mg/dL (3.5–7.8 mmol/L), citing a lack of direct evidence to support such a change. Instead, they reaffirm the long-established fasting (<95 mg/dL [5.3 mmol/L]), one-hour postprandial (<140 mg/dL [7.8 mmol/L]), and two-hour postprandial <120 mg/dL [6.7 mmol/L]) standard-of-care targets. Moreover, adopting a single TIR target could obscure the important contribution of fasting/overnight hyperglycemia to adverse outcomes (e.g., large-for-gestational age [LGA] infants). The panel identified indirect evidence supporting the need to achieve overnight/fasting glucose values as required in traditional targets.

Indeed, different circadian patterns of dysglycemia were associated with different adverse outcomes. Using a well-controlled mean glucose level 123 mg/dL (6.83 mmol/L) as a reference point, suboptimal control with high variability (mean glucose 154 mg/dL [8.6 mmol/L]) was associated with higher rates of LGA infants; suboptimal control with minimal circadian variation (mean glucose 148 mg/dL 8.3 mmol/L]) was associated with higher rates of preterm birth, cesarean delivery, and neonatal intensive care unit (NICU) admissions (but no significant increase in LGA infants, neonatal hypoglycemia, or maternal preeclampsia); and poor control with peak overnight hyperglycemia (mean glucose 166 mg/dL [9.2 mmol/L]) was associated with higher rates of maternal preeclampsia, LGA infants, neonatal hypoglycemia, and NICU admissions. Thus, not all hyperglycemia is equal, and different patterns of dysglycemia may require individualized management strategies.

Despitethese findings supporting maintaining standard-of-care targets, with CGM use increasing, time in range (TIR) becomes an important supplementary metric. “Some recommendations already present in the previous version have been implemented and updated,” Lapolla explains, “in particular those related to the use of CGM and insulin pump administration, due to the fact that in the last few years these technologies have been implemented.” For those with type 1 diabetes, maintaining more than 70% TIR is recommended; for those with type 2 diabetes, 80% to 90% TIR is recommended. Nevertheless, while CGM provides valuable data, interpreting that data with an understanding of how different patterns affect outcomes remains essential for optimizing pregnancy care in diabetes.

Another notable recommendation in this category regards the use of hybrid closed loop (HCL) systems. The panel conditionally recommended that women with type 1 diabetes — but not type 2 diabetes — might benefit from this technology. The recommendation arises from the (albeit, limited) evidence indicating improved TIR (and correspondingly less time below range [TBR]) as well as overnight control. The recommendation remains conditional based on potential higher costs and the need for support (education, training) to implement the technology.

Delivery Timing. Delivery before 39 weeks (38 0/7 to 38 6/7 weeks) rather than expectant management is conditionally recommended. This recommendation based on very low certainty evidence reflects the panel’s careful approach to this complex decision, with the risks of continued pregnancy (stillbirth, birth trauma, maternal complications, and hypertensive disorders) outweighing those of early delivery (neonatal morbidity related to prematurity, including respiratory distress, hypoglycemia, and NICU admission).

Importantly, this recommendation represents a nuanced evolution from previous guidance from ACOG, who formerly recommended delivery at 39 0/7 to 39 6/7 weeks for well-controlled diabetes without complications and delivery at 36 0/7 to 38 6/7 weeks for vascular complications, poor glucose control, or prior stillbirth. The new guidelines emphasize a more risk-stratified approach toward early term delivery (38 0/7 to 38 6/7 weeks) based on individualized risk assessment.

Navigating Carbohydrate Intake. “Given the increase in type 2 diabetes associated with obesity worldwide and women with this pathology who become pregnant, these recommendations have also addressed the issues related to correct nutrition and therapeutic approach in such women,” Lapolla notes.

With carbohydrate being the main macronutrient that determines postprandial hyperglycemia, the panel judged that either carb-restricted diets (<175g daily) or regular diets are acceptable (based on limited evidence). This balanced recommendation reflects the uncertainty in the current evidence and recognizes that different approaches may be appropriate for different individuals. The 175-g threshold relates to the Institute of Medicine’s (IOM) nutrition guidelines, which recommend that pregnant women consume at least 175 grams of carbohydrates daily to promote fetal growth and brain development. Some experts even suggest 220 grams to account for the estimated 35 grams of carbohydrate required by the placenta in the third trimester. However, the IOM threshold may overestimate the true requirement (97.5% of the population requires less) and does not account for glucose derived from gluconeogenesis.

Thus, while the guidelines do not recommend a specific carbohydrate intake, they highlight maternal and fetal dangers at both extremes: restriction (<100 g/day) can lead to, for example, fetal neural tube defects (NTDs); excess (>200 g/day) can double the risk of, for example, poor maternal glycemic control with the associated cascade of deleterious effects.

Medication Considerations. Although insulin resistance naturally increases during pregnancy, adding metformin to insulin as a low-cost way to improve insulin sensitivity is not routinely recommended. Metformin crosses the placenta readily, achieving fetal levels at least as high as maternal levels and thus might increase rates of small-for-gestational-age (SGA) infants, while simultaneously increasing rates of childhood overweight/obesity at ages five to 10 years.

“Obesity, hypertension, and other diabetes complications determine risks of adverse outcomes of pregnancy. So, it is strongly necessary to provide recommendations for the care of individuals with preexisting diabetes in order to reduce maternal and neonatal adverse outcomes.” –  Annunziata Lapolla, MD, University of Padova, Padua, Italy

Another key recommendation regards the use of glucagon-like peptide-1 (GLP-1) receptor agonists in pregnancy, for the first time. The panel faced the core dilemma of weighing potential unknown risks of GLP-1RA exposure to the developing embryo/fetus with the dangers of rebound maternal hyperglycemia and weight gain with medication discontinuation after conception (and potential fetal consequences such as NTDs and cardiac and other congenital anomalies, among others).

Therefore, the panel recommends that GLP-1 medications should be stopped before conception rather than during early pregnancy to balance medication safety concerns with risks of sudden blood glucose changes, while acknowledging that the timing is not one-size-fits-all. The panel also explicitly recognized that in real-world settings, many women will be exposed to GLP-1RAs in early pregnancy despite this recommendation, emphasizing the importance of developing contingency protocols for this scenario.

Evidence Gaps and Research Horizons

Despite the panel’s rigorous approach, many recommendations rest on limited evidence. “Some of the questions we sought to answer have limited data on which to base recommendations,” Wyckoff acknowledges. “GRADE Methodology relies heavily on RCTs, but much of the evidence available to support recommendations in this field is indirect.” This evidence limitation creates space for debate. “I expect there will be great discussions around several of these recommendations,” Wyckoff adds, “which will hopefully lead to stronger evidence and a clearer picture for best practices.”

Looking ahead, Lapolla also identifies critical research needs: “RCTs to define the optimal glycemic targets in pregnancy and implementation of the technologies to achieve those targets are mandatory. Data on optimal nutrition and obesity management in pregnancy are lacking, so clinical studies in this context are necessary.”

Bottom Line for Clinicians

For clinicians, the message is clear: comprehensive management that begins before conception is key. “The implementation of PCC is crucial to prevent the negative maternal and fetal outcomes in women with preexisting diabetes,” Lapolla says. This includes not only glycemic control but also managing obesity, hypertension, and other complications that influence pregnancy risks.

By bringing together the latest evidence on technology use, medication management, and risk assessment, these guidelines offer a roadmap for navigating the complex terrain of diabetes care during pregnancy — while acknowledging that work is still to be done to achieve optimal evidence-based practice and that individual patient factors must always be considered.

Horvath is a freelance writer based in Baltimore, Md. In the June issue, she wrote about the ENDO 2025 session “Bariatric Surgery and Emerging Medications: Redefining Roles and Mechanisms.”