Status:Enrolling by invitation
Keywords:Diabetes in pregnancy , Gestational diabetes , Pregnancy
Gestational diabetes (GDM) affects 3-12% of all pregnancies and is associated with adverse maternal and neonatal outcomes. These include higher rates of preeclampsia, operative delivery, macrosomia, shoulder dystocia and other birth injuries. GDM has also been linked to long-term risk of childhood obesity and impaired glucose tolerance. Due to the availability for treatment and mitigation of the above risks with achievement of euglycemia, the American College of Obstetrics and Gynecology recommends screening all pregnant women for GDM in the late second to early third trimesters. Patients considered at increased risk for GDM (such as maternal age >35, multiple gestation, obesity, or previous history of GDM and/or fetal macrosomia) are often screened in the late first or early second trimester in hopes of diagnosing previously undetected diabetes mellitus or early GDM.
The initial screen consists of a 50 gram glucose tolerance test. Confirmation of the diagnosis is made with two abnormal values in a 3-hour, 100 gram oral glucose tolerance test (OGTT). Unfortunately, because of the need for a fasting value, the 3-hour OGTT is often delayed by several days or until the next visit, decreasing the window for adequate patient education and treatment. Recently, the American Diabetes Association approved the use of a hemoglobin A1C screen for the diagnosis of diabetes mellitus with a value >/=6.5% being the cutoff point. A short-term marker of glycemic control, glycated albumin, has been used in the adult diabetic population to assess glycemic excursion. It remains unknown if a screening hemoglobin A1C and/or glycated albumin would be of utility in the diagnosis of GDM. Additionally, with the increasing insulin resistance that occurs as all pregnancies progress in the third trimester, normative values for hemoglobin A1C and glycated albumin during pregnancy are not yet established. These laboratory tests could be drawn simultaneously with the routine screening currently performed in the 24-28 week gestation or even in the first trimester for patients considered at high risk for GDM or undiagnosed diabetes mellitus.
Given that both a screening hemoglobin A1C and glycated albumin would not require confirmatory testing and do not need to be performed fasting, this may allow women to initiate treatment or dietary modifications to achieve euglycemia within a shorter period of time.
The specific objectives of the study are:
1) To determine whether HbA1c and glycated albumin obtained in the first trimester will correlate with abnormal 50 gram glucose screening results in at-risk patients
2) To determine if albumin alone or in concert with HbA1c obtained at 24-28 weeks gestation (simultaneous with universal 50 gram glucose screening) will correlate with 50 gram glucose results and 3 hour OGTT results
Principle Investigator: David Branch
Principle Department: Maternal-Fetal Medicine
We will enroll up to 115 women with a BMI (Body Mass Index) >25 as well as 20 lean controls in the first trimester of pregnancy.
As part of the amendment, we would also like to enroll up to 40 patients with a BMI > 25 (not already enrolled in the first trimester) in the second trimester alone for a single lab draw at that time, as opposed to a first trimester and second trimester draw. This may require the recruitment of a total of 175 patients.
Patients will be excluded if they have a history of anemia (defined as hematocrit <30), or hemogobinopathy, previous history of diabetes type 1 or 2, nephropathy, chronic liver disease, malignancy, thyroid diesase, or concurrent oral steriod use for any indication. Patient will also be excluded if the dating (estimated due date) of the pregnancy is not confirmed by a first or second trimester ultrasound.