What laboratory tests or diagnostic procedures are indicated for a 24-year-old pregnant patient with a body mass index (BMI) of 30 at 11 weeks and 2 days gestation during a routine obstetric (OB) visit?

From the Guidelines

For a 24-year-old pregnant patient with a BMI of 30 at 11 weeks and 2 days gestation, I recommend ordering the following routine first trimester labs and tests: Complete blood count (CBC), blood type and Rh factor with antibody screen, rubella immunity status, hepatitis B surface antigen, HIV testing, syphilis screening, urine culture, and a Pap smear if not done within the past 3 years. Additionally, offer cell-free DNA screening or first trimester combined screening (ultrasound nuchal translucency with serum PAPP-A and beta-hCG) for aneuploidy assessment. Due to her BMI of 30, early screening for gestational diabetes with a hemoglobin A1C is appropriate, with a follow-up glucose tolerance test at 24-28 weeks, as recommended by the American Diabetes Association 1. Consider screening for chlamydia and gonorrhea, especially if she has risk factors. Thyroid stimulating hormone (TSH) testing is also recommended to rule out subclinical hypothyroidism. These tests establish baseline health parameters, identify pre-existing conditions that may affect pregnancy, screen for infections that could harm the fetus, and assess risk factors related to her elevated BMI, which slightly increases her risk for complications like gestational diabetes and preeclampsia.

Some key points to consider:

• The American Diabetes Association recommends screening for gestational diabetes at 24-28 weeks of gestation in women with risk factors, such as a BMI of 30 or higher 1.
• The U.S. Preventive Services Task Force recommends screening for gestational diabetes after 24 weeks of gestation, but notes that screening may occur earlier in high-risk women 1.
• The American College of Obstetricians and Gynecologists recommends a two-step approach for screening and diagnosis of gestational diabetes, with a 50-g glucose challenge test followed by a 100-g oral glucose tolerance test if the initial test is abnormal 1.
• Early screening for gestational diabetes with a hemoglobin A1C may be appropriate in women with risk factors, such as a BMI of 30 or higher, but this should be followed by a glucose tolerance test at 24-28 weeks if the initial test is abnormal.

It's worth noting that while there are different guidelines and recommendations for screening and diagnosis of gestational diabetes, the goal is to identify women at risk and provide appropriate management to reduce the risk of complications for both the mother and the fetus.

From the Research

Routine Labs and Tests for a 24-Year-Old Pregnant Woman with a BMI of 30 at 11 Weeks and 2 Days Gestation

• The patient's BMI is 30, which falls into the obese category, increasing her risk for gestational diabetes mellitus (GDM) 2, 3, 4, 5, 6
• Given the patient's age and BMI, it is essential to screen for GDM early in pregnancy to minimize adverse pregnancy outcomes and long-term complications for both the mother and the offspring 2, 6
• The following labs and tests are recommended:
  • 50g glucose challenge test (GCT) to screen for GDM, with a threshold plasma glucose level of 140 mg/dl or 7.8 mmol/l 3, 4, 5
  • If the GCT result is abnormal, a 3-hour 100g oral glucose tolerance test (OGTT) or a 2-hour 75g OGTT should be performed to confirm the diagnosis of GDM 2, 4, 5
  • Other routine labs, such as complete blood count, blood type, and urine analysis, should also be considered as part of the patient's prenatal care
• It is crucial to note that the 50g GCT is a screening test and not a diagnostic test, and further testing is required to confirm the diagnosis of GDM 4, 5
• The patient's risk factors, such as obesity, should be taken into account when interpreting the results of the GCT and deciding on further testing 5, 6