Women diagnosed with gestational diabetes in the first 12 weeks of pregnancy experience a higher incidence of preeclampsia, preterm delivery, cesarean section and neonatal jaundice than women diagnosed later in pregnancy, despite early testing and intensive treatment, according to research in Diabetes Care.
In a large multiethnic cohort study of high-risk pregnant women in Australia, researchers also found that the higher risk for adverse outcomes was not explained by women with pre-existing type 2 diabetes who were diagnosed early on in pregnancy.
“This study demonstrates that, despite intensive intervention, early [gestational diabetes] in high-risk women is associated with suboptimal outcomes, and that this increased risk is associated with dysglycemia lower than the threshold for diabetes in pregnancy,” Arianne N. Sweeting, PhD, of the Royal Prince Alfred Hospital – Diabetes Center in Sydney, and colleagues wrote.
Sweeting and colleagues analyzed data from 4,873 women attending the antenatal diabetes clinic at Royal Prince Alfred Hospital between 1991 and 2011, all treated to standard glycemic targets. Within the cohort, 65 women were diagnosed as having pre-existing type 2 diabetes (mean age, 35 years; 29% Chinese/Southeast Asian; 84% with family history of diabetes); 68 women were diagnosed with gestational diabetes within the first 12 weeks of pregnancy (mean age, 35 years; 35% white; 62% with family history of diabetes); 1,247 were diagnosed with gestational diabetes between 12 and 23 weeks gestation (mean age, 35 years; 47% Chinese/Southeast Asian; 58% with family history of diabetes); 3,493 diagnosed with gestational diabetes at 24 weeks gestation or later (mean age, 33 years; 38% Chinese/Southeast Asian; 48% with family history of diabetes). Women with type 1 diabetes were excluded from the study.
Women with pre-existing diabetes (25.9%) and gestational diabetes diagnosed in the first 12 weeks of pregnancy (16.7%) delivered babies earlier and experienced more preterm delivery vs. women diagnosed between 12 and 23 weeks (11.2%) and women diagnosed at 24 weeks or later (6.4%). Additionally, Women with pre-existing diabetes (34.6%) and gestational diabetes diagnosed in the first 12 weeks of pregnancy (26.3%) experienced higher rates of preeclampsia vs. women diagnosed between 12 and 23 weeks (13.8%) and women diagnosed at 24 weeks or later (11.2%). Women with pre-existing type 2 diabetes experienced the highest cesarean section rate (57.9%), followed by women diagnosed with gestational diabetes between 12 and 23 weeks (36.2%), women diagnosed in the first 12 weeks of pregnancy (30.7%) and women diagnosed at 24 weeks or later (28.1%).
Women with pre-existing diabetes and early gestational diabetes also experienced the highest rates for neonatal jaundice (41.7% and 28.1%, respectively), macrosomia (21.8% and 20.3%, respectively) and babies born large for gestational age (39.6% and 32.8%, respectively) than women diagnosed with gestational diabetes later in pregnancy. Admission rates for neonatal intensive care were similar across all four groups (P < .04).
“Alarmingly, the highest rate of stillbirth was seen in women in whom [gestational diabetes] was diagnosed at < 12 weeks of gestation rather than (as would be expected) in women with type 2 diabetes,” the researchers wrote. “Conversely, later [gestational diabetes] was associated with the lowest risk for adverse neonatal outcomes.” – by Regina Schaffer
the researchers report no relevant financial disclosures.