Diabetes in pregnancy 100 years after the discovery of insulin: Hot topics and open questions to be addressed in the coming years.

By making it possible for women with diabetes to achieve their family planning goals, the discovery of insulin ushered in the field of diabetes in pregnancy. The ensuing century has witnessed tremendous advances, with clinical focus on preconception planning and maternal glycemic control making successful pregnancy an achievable goal. Currently, the global epidemic of overweight/obesity has led to maternal hyperglycemia now affecting one in every six pregnancies worldwide, prompting intense research interest. Topics of particular interest include (i) the optimal approach to diagnosing gestational diabetes mellitus (GDM); (ii) the emergence of GDM as a chronic metabolic disorder identifying future risk of non-communicable disease; (iii) the transgenerational impact of maternal glycemia as per the Developmental Origins of Health and Disease; and (iv) the application of new technology for optimizing clinical management. These topics have raised exciting questions such as (i) whether the treatment of diabetes in pregnancy can impact growth/development in childhood, (ii) whether GDM can be prevented, and (iii) whether the diagnosis of GDM could facilitate the prevention of type 2 diabetes and cardiovascular disease. Indeed, this field may be on the precipice of a golden era of new concepts and evidence to optimize the health of mother and child.

Diabetes during pregnancy and perinatal outcomes among First Nations women in Ontario, 2002/03-2014/15: a population-based cohort study.

BACKGROUND: In Canada, increasing numbers of women, especially First Nations women, are affected by diabetes during pregnancy, which is a major risk factor for adverse maternal and neonatal outcomes. The aim of this study was to examine temporal trends in pregnancy outcomes and use of health care services in a population-based cohort of First Nations women compared to other women in Ontario according to diabetes status during pregnancy. METHODS: Using health administrative databases, we created annual cohorts of pregnant women from 2002/03 to 2014/15 and identified those with preexisting diabetes and gestational diabetes. We used the Indian Register to identify First Nations women. We estimated rates of adverse maternal and infant outcomes, and measures of use of health care services in each population. RESULTS: There were 1 671 337 deliveries among 1 065 950 women during the study period; of these deliveries, 31 417 (1.9%) were in First Nations women, and 1 639 920 (98.1%) were in other women. First Nations women had a higher prevalence of preexisting diabetes and gestational diabetes than other women in Ontario. First Nations women with preexisting diabetes had higher rates of preeclampsia (3.2%-5.6%), labour induction (33.4%-42.9%) and cesarean delivery (47.8%-53.7%) than other women in Ontario, as did First Nations women with gestational diabetes (3.2%-4.7%, 38.5%-46.9% and 41.4%-43.4%, respectively). The rate of preterm birth was similar between First Nations women and other women in Ontario. Although First Nations women had a higher rate of babies who were large for gestational age than other women, regardless of diabetes status, obstructed labour rates were similar for the 2 cohorts. Almost all First Nations women, regardless of diabetes status, were seen by a primary care provider during their pregnancy, but rates of use of specialty care were lower for First Nations women than for other women. Fifteen percent of all pregnant women with preexisting diabetes visited an ophthalmologist during their pregnancy. INTERPRETATION: Our results confirm disparities in maternal and neonatal outcomes between First Nations women and other women in Ontario. Access to primary care for pregnant women seemed adequate, but access to specialized care, especially for women with preexisting diabetes, needs to improve.

Glycemic targets in pregnancies affected by diabetes: historical perspective and future directions.

The definition of optimal glycemic control in pregnancies affected by diabetes remains enigmatic. Diabetes phenotypes are heterogeneous. Moreover, fetal macrosomia insidiously occurs even with excellent glycemic control. Current blood glucose (BG) targets (FBG ≤95, 1-h post-prandial <140, 2 h <120 mg/dL) have improved perinatal outcomes, but arguably they have not normalized. The conventional management approach has been to replicate a pattern of glycemia in normal pregnancy. Although these patterns are lower than previously appreciated, a randomized controlled trial (RCT) has never compared current vs. lower glucose targets powered on maternal/fetal outcomes. This paper provides historical context to the current targets by reviewing evidence supporting their evolution. Using lower targets (FBG <90, 1 h <122, 2 h <110, mean BG ≤95 mg/dL) may help normalize outcomes, but phenotypic differences (type 1 vs. type 2 vs. gestational diabetes) might require different glycemic goals. There remains a critical need for well-designed RCTs to confirm optimal glycemic control that minimizes both small for and large for gestational age across pregnancies affected by diabetes.

A historical perspective on gestational diabetes.

Extreme fetal macrosomia occurred in the first recorded case of diabetes in pregnancy in 1823. The belief that the diabetic condition was in some way a symptom of the pregnancy, which dates to that first report, has led to the more recent concept of gestational diabetes. Lesser degrees of maternal hyperglycemia were also recognized to be a risk to the baby, and early studies of carbohydrate intolerance in pregnancy in Boston and Los Angeles have set the stage for the worldwide interest in this maternal/fetal interaction.