144 Obstetrics and Gynecology Board Review •••
❍ When should women with trichomoniasis be treated and what is the risk of treatment?
Treatment should be given to symptomatic women. 2 g of metronidazole in a single dose is the most effective
regimen. Treatment may increase the risk of preterm birth; however, the exact risk remains unknown.
ENDOCRINE
Diabetes
❍ When should the 50 g 1-hour oral glucose challenge test be administered?
24 to 28 weeks gestation.
❍ What is the cutoff value that gives 90% sensitivity for gestational diabetes?
130 mg/dL. 140 mg/dL cutoff is 80% sensitive.
❍ What is the diagnostic test for gestational diabetes?
Women who screen positive in the glucose challenge test should receive the 100 g, 3-hour oral glucose tolerance
test, which should be performed in a fasting state.
❍ What are the Carpenter-Coustan criteria for the diagnosis of gestational diabetes mellitus?
Fasting: 95 mg/dL, 1 hour: 180 mg/dL, 2 hours: 155 mg/dL, 3 hours: 140 mg/dL. Two or more abnormal values
give a diagnosis of gestational diabetes.
❍ What is the rate of recurrence of gestational diabetes in a subsequent pregnancy?
33% to 50%.
❍ What is the effect of primary dietary therapy for gestational diabetes on fetal growth and neonatal
outcomes?
There is no significant effect on birth weight >4000 g or cesarean delivery.
❍ When should medical intervention be considered for gestational diabetes mellitus?
When fasting blood sugars are >95 mg/dL or 2-hour postprandial values are >120 mg/dL.
❍ What is the prevalence of pregestational diabetes in the United States?
1% of all pregnancies.
❍ Is insulin resistance increased or decreased during pregnancy?
Insulin sensitivity is enhanced late in the first trimester by higher levels of estrogen, but later in pregnancy insulin
resistance increased and is greatest in the third trimester.
❍ Which hormones contribute to the increase in insulin resistance?
Placental hormones including human placental lactogen (hPL), progesterone, prolactin, placental growth
hormone, and cortisol. TNF alpha and leptin also contribute.