Invited commentary: Advancing the management of type 2 diabetes in pregnancy

Type 2 diabetes is a growing challenge among women of reproductive age worldwide1 and now accounts for approximately 50% of pregnancies complicated by pre-existing diabetes In England and Wales.2 Pregnancies complicated by type 2 diabetes are associated with increased rates of neonatal morbidity and mortality, underscoring the pressing need for effective management strategies.2 The complexities of type 2 diabetes in pregnancy are manifold, accompanied by maternal medical and mental health co-morbidities and substantial health inequalities, all contributing to a high burden of maternal and neonatal complications. Indeed, a recent systematic review and meta-analysis, confirmed that women with type 2 diabetes were more likely to have a small for gestational-age (SGA) baby than those with type 1 diabetes and to experience higher perinatal mortality compared to type 1 diabetes, gestational diabetes and control pregnancies.3 The UK national audit confirms that pre-pregnancy care for women with type 2 diabetes has remained persistently suboptimal over the past two decades.2 Women with type 2 diabetes are far less likely to be well prepared for pregnancy compared to those with type 1 diabetes. The ongoing disparity in pre-pregnancy care is a critical concern, as it contributes to the heightened risk of perinatal and neonatal deaths in type 2 diabetes pregnancy.2 Three systematic reviews have shed light on these multifaceted aspects by examining evidence from randomised controlled trials,4 observational studies5 and qualitative research into women's experiences.6 Taken together, these papers highlight the clinical challenges and illuminate the lived realities of women navigating pregnancy with type 2 diabetes. Gunabalasingam et al.4 conducted a systematic review of 11 randomised controlled trials, with study sample sizes ranging from 25 to 502, among 1356 women with type 2 diabetes. They found that clinical interventions were predominantly pharmacological, with only limited focus on behavioural or lifestyle modifications, despite their importance before and during type 2 diabetes pregnancy. Notably, a large-scale randomised trial (MiTy) demonstrated that adding metformin to insulin improved maternal glycaemic control, reduced insulin doses and minimised gestational weight gain (GWG). However, whilst metformin modestly lowered the incidence of large-for-gestational-age (LGA) infants, composite neonatal outcomes and some markers of neonatal adiposity did not differ. Consequently, 40% of neonates still experienced complications related to maternal glucose and the reduction in LGA was tempered by an increase in SGA infants.7 A subsequent secondary analysis of the MiTy trial,8 in women with polycystic ovary syndrome (PCOS), suggested that metformin was potentially associated with worsening of pre-existing hypertension and a higher rate of LGA infants. These findings indicate that while metformin shows promise, as an adjunct or alternative to insulin, its effects may vary across different subgroups, necessitating more personalised therapeutic approaches. Few trials have investigated more complex behavioural and lifestyle modifications. One Indian study suggests that aerobic exercise may enhance placental blood flow and improve maternal fasting glucose levels,9 but more data on the role of exercise interventions are needed. No randomised controlled trials have specifically addressed the role of type 2 diabetes remission during the postpartum or preconception periods or following pregnancies complicated by gestational diabetes, which is a crucial missed opportunity to improve maternal-fetal outcomes. The literature on continuous glucose monitoring (CGM) in pregnant women with type 2 diabetes is similarly limited by small studies using outdated technology, with inadequate statistical power to demonstrate differences in maternal-fetal outcomes. Larger, randomised studies like the ongoing PROTECT (ISRCTN12804317) and CGM2 (NCT06628453) trials in the UK and USA, respectively, aim to evaluate the clinical and cost-effectiveness of CGM use in type 2 diabetes pregnancy. Observational studies underscore the importance of modifiable risk factors—namely maternal glucose, BMI and excessive GWG—as key determinants of pregnancy outcomes.5 Metformin is a widely accepted tool for managing maternal weight, with some studies suggesting its use is associated with modest reductions in GWG and fewer caesarean deliveries, without an accompanying increase in the risks of preterm births or SGA infants.5 In contrast, there is a lack of evidence supporting the use of newer and potentially more effective weight management therapies such as semaglutide and tirzepatide, which are increasingly used by women of reproductive years before and after pregnancy.10 Available evidence does not suggest cause for clinical concern,11 with no apparent increase in congenital anomalies in two large-scale cohort studies investigating early pregnancy exposure to GLP1 receptor agonists (GLP1-RAs).12, 13 However, these therapies are typically discontinued around conception due to lack of data regarding the risks and benefits of ongoing use. Moreover, GLP1-RAs have shown promise in improving maternal risk factors, such as glycaemic control and BMI, becoming an effective support in pregnancy planning. A recent cohort study14 examined nearly 4000 people who were exposed to GLP1-RAs in the 24 months before pregnancy, comparing them with a matched unexposed group. Findings indicated a reduced risk of adverse obstetrical outcomes among those exposed to GLP1-RAs. Nevertheless, only 37% of women had type 2 diabetes diagnosis, compared to 1.5% of the unexposed group, highlighting the need for specific trials that take account of the strong impact of glycaemic control in addition to maternal BMI. While preconception care with reduction in periconception, HbA1c is well established to offer benefits for reducing adverse pregnancy, birth and neonatal outcomes, evidence linking specific components such as increased use of folic acid and vitamin D to significant improvements remains patchy.5 Similarly, the evidence linking preconception or antenatal care pathways tailored specifically for women with type 2 diabetes is under-researched, highlighting gaps in our understanding of how best to support this growing and often vulnerable population, with data from the UK showing seven times more type 2 diabetes pregnancies in women from the most compared to least deprived communities.2 Complementing the clinical data, qualitative studies provide a compelling narrative into the personal challenges faced by women with type 2 diabetes during pregnancy.15 Studies describe a landscape marked by substantial psychosocial barriers, including heightened anxiety, diminished self-efficacy and a pervasive sense of fragmented care. Many women report feeling unsupported by healthcare providers, compounded by inconsistent advice and a lack of integration between reproductive health, diabetes and weight management. These narratives reinforce the need for patient-centred, multidisciplinary approaches that not only address medical needs but also foster maternal wellbeing, with enhanced continuity of care and peer support. Over the past two decades, limited progress has been made in managing type 2 diabetes in pregnancy, with substantial gaps persisting throughout prepregnancy, antenatal and postnatal care. Addressing modifiable risk factors through targeted research and innovative, integrated care strategies is essential for improving outcomes for both mothers and their infants. Bridging these gaps will require a concerted effort to develop and implement evidence-based glycaemic, weight management and wellbeing interventions that address the holistic needs of women with type 2 diabetes. None of the authors have a conflict of interest to disclose.