Diabetes in pregnancy includes two categories of patients: those who have type 1 or type 2 diabetes prior to pregnancy and those who develop gestational diabetes during a pregnancy. Gestational diabetes may progress to type 2 diabetes after pregnancy in some females.
The prevalence of gestational diabetes can vary depending on the data source, diagnostic criteria, and the demographics of the population studied. The most recent data, taken from a retrospective insurance claims analysis, has estimated the prevalence at 6.29%. The range of data available is provided in Table 22.
|MarketScan database, 2004-2011||Pregnant females, age 18-45 years||6.29%||Jovanovic et al. 20155|
|Pregnancy Risk Assessment Monitoring System, 2009-2010 and birth certificate records (2010)||Pregnant females, all ages||4.6%-9.2%||DeSisto et al. 201463|
|Kaiser Permanente Southern California hospital records, 1999-2005||Pregnant females, age 13-58 years||7.6%||Lawrence et al. 200864|
|National Hospital Discharge Survey, 2003-2004||Pregnant females, age 14-45 years||4.2%||Getahun et al. 200865|
As with other types of diabetes, an increase in the prevalence of gestational diabetes has been observed over time. Using data from the National Hospital Discharge Survey, Getahun et al. noted a relative increase of 122% between the 1989-1990 survey to the 2003-2004 survey.65
Analysis of records from all Kaiser Permanente hospitals in Southern California showed that the prevalence of pre-existing diabetes among pregnant females rose from 0.81% in 1999 to 1.82% in 2005.64 An additional retrospective study of insurance claims data in the MarketScan database (for years 2004-2011) provided additional insights on the prevalence of pre-existing type 1 diabetes versus type 2 diabetes among pregnant females (Table 23). Further, this study noted that the rate of gestational diabetes progressing to type 2 diabetes in their cohort was 0.23%.5
|Truven Health MarketScan database (2004-2011), retrospective claims analysis||Pre-existing type 1 diabetes||0.13%|
|Pre-existing type 2 diabetes||1.21%|
Source: Jovanovic et al. 20155
Data from PRAMS collected between 2004 and 2006, indicated that prevalence increased with maternal age66,67, as shown in Table 24. 66
|Under 20 years||1.0%|
Source: Kim et al. 201066
Several studies have shown an increase in gestational diabetes prevalence from the late 1980s until the early 2000s (Table 25), but prevalence levels have remained fairly stable since then. In addition, new diagnostic criteria may result in a 2- to 3-fold increase in the diagnosed prevalence of gestational diabetes.67
|Data Source||Population||Change Over Time||Reference|
|1989-1990 and 2003-2004 NHDS||Pregnant females with gestational diabetes||Relative increase of 122%(1.9% in 1989-90 to 4.2% in 2003-04)||Getahun et al. 200865|
|1991, 1997 and 2000 KPNC||Pregnant females with gestational diabetes||Increased 68% from 1991-1997 (3.7% to 6.6%) then leveled off at 6.2% through 2000||Ferrara et al. 200768|
|1999 and 2005 KPSC||Pregnant females with gestational diabetes||Remained constant from 1999 (7.5%) to 2005 (7.4%)||Lawrence et al. 200864|
|1999 and 2005 KPSC||Pregnant females with existing diabetes||Increased from 0.81% in 1999 to 1.82% in 2005||Lawrence et al. 200864|
Abbreviations: KPNC, Kaiser Permanente Northern California; KPSC, Kaiser Permanent Southern California; NHDS, National Hospital Discharge Survey
Gestational diabetes in 1995–2008 was more prevalent among Hispanics and Asian/Pacific Islanders than among whites or blacks, as indicated in an analysis of hospital records from Kaiser Permanente Southern California69 (Table 26).
Source: Xiang et al. 201169
NHDS data showed that between 1989–1990 and 2003–2004, among females under 25 years old, the frequency of gestational diabetes increased by 13% among whites and 260% among blacks.65
Pregnancy-related mortality ratios increase with maternal age for all females and within all age groups, and non-Hispanic black females have the highest risk of dying from pregnancy complications (Table 27).
|Race/ethnicity||Deaths per 100,000 live births|
Source: Creanga et al. 201570
Over time, the contribution to pregnancy-related deaths of hemorrhage, hypertensive disorders of pregnancy, embolism, and anesthesia complications continued to decline, whereas the contribution of cardiovascular conditions and infection increased (Table 28).
|Cause of death||Percent of pregnancy-related deaths|
Source: Creanga et al. 201570
Among the causes, cardiovascular conditions ranked first, with 14.4% of 490 maternal deaths occurring after a live birth, 11.4% after a stillbirth, 7.8% after an abortion, 20.2% with the fetus undelivered, and 12.7% unknown.70
A retrospective analysis of insurance claims in the MarketScan Commercial Claims and Encounters database showed that between the years 2000-2011, the use of glyburide (an oral sulfonylurea medication, also known as glibenclamide) to treat gestational diabetes increased from 7.4 to 64.5%.71 The data indicated that since 2007, glyburide surpassed insulin as the most common treatment for gestational diabetes. Its use is somewhat controversial because glyburide is not approved by the US Food and Drug Administration for treatment of gestational diabetes, though it has been recommended by the Endocrine Society72 and the American College of Obstetrics and Gynecology73 as a suitable alternative to insulin if necessary. A systematic review and meta-analysis of the literature found that glyburide is inferior to both insulin and metformin to treat gestational diabetes, though treatment failure was higher with metformin than with glyburide; this report recommended against using glyburide to treat gestational diabetes if insulin or metformin was available as an option.74
Among the 10% of all pregnancies in the US complicated by diabetes, 0.2% to 0.5% involve type 1 diabetes; both fetus and mother are at increased risk for adverse effects. A 2011 literature review advised a rigorous protocol of pre-conception counseling, carbohydrate counting, use of insulin analogues, continuous subcutaneous insulin infusion (insulin pump) therapy, and real-time continuous glucose monitoring with alarms for low glucose values to obtain near-normoglycemia without episodes of severe hypoglycemia.75
Beyond drug treatment, increasing physical activity has the effect of reducing the risk of type 2 diabetes among pregnant females. Compared with females who maintained their total physical activity levels, females who increased their total physical activity levels by 7.5 metabolic equivalent hours/week or more (equivalent to 150 minutes per week of moderate-intensity physical activity) had a 47% lower risk of type 2 diabetes. This association remained significant after additional adjustment for BMI.76
Immediately subsequent to pregnancy, about 5%–10% of females with gestational diabetes are diagnosed with type 2 diabetes, and females who have had gestational diabetes have a 35%–60% risk of developing type 2 diabetes in the next 10 to 20 years.27 The risk of subsequent overt type 2 diabetes accumulates over time and the same is likely for cardiovascular disease.77 Females with previous gestational diabetes are at the risk of developing it again in subsequent pregnancies78. The risk of gestational diabetes in a second pregnancy among females with a history of the disease was 41.3%, compared to 4.2% in females without a prior diagnosis.78
Although having gestational diabetes is known to increase the risk of developing type 2 diabetes later in life, the most recent findings indicate that lifestyle interventions – specifically, increased exercise – can decrease that risk.76
Patients with pre-existing diabetes who become pregnant are at greater risk for maternal and fetal complications than their nondiabetic counterparts. In a study of 213 pairs of type 2 diabetes patients and control patients from 2000 to 2008, patients with diabetes had higher rates of preeclampsia, poly- and oligohydramnios, cesarean delivery, shoulder dystocia, postpartum hemorrhage, preterm delivery, large-for-gestational age infant, fetal anomaly, neonatal hypoglycemia, hyperbilirubinemia, respiratory distress syndrome, sepsis, intubation, and neonatal intensive care unit admission.79
The role of intrauterine hyperglycemia and future risk of type 2 diabetes in human offspring appears to be involved in the pathogenesis of type 2 diabetes/pre-diabetes in adult offspring of primarily Caucasian females with either diet-treated GDM or type 1 diabetes during pregnancy. In a study of glucose tolerance among adult offspring of females with either gestational diabetes mellitus (GDM) or type 1 diabetes, taking the impact of both intrauterine hyperglycemia and genetic predisposition to type 2 diabetes into account, the risk for type 2 diabetes or pre-diabetes was increased by 4.02 to 7.76% in offspring of mothers with type 1 diabetes and was significantly related to the mother’s having elevated blood glucose in late pregnancy.80