What labs should be drawn at the first prenatal appointment?

From the Guidelines

At the first prenatal appointment, essential laboratory tests should be drawn to establish baseline health status and identify potential complications, including a complete blood count, blood type and Rh factor with antibody screening, rubella immunity status, hepatitis B surface antigen, HIV testing, syphilis screening, urinalysis and urine culture, and cervical screening for gonorrhea and chlamydia, as well as screening for gestational diabetes with either a hemoglobin A1C or glucose challenge test, particularly in women with risk factors for diabetes, as recommended by the American Diabetes Association 1. These tests are crucial for early identification of conditions that could affect maternal and fetal health, allowing for timely interventions that improve pregnancy outcomes.

• A complete blood count to assess for anemia and platelet levels is necessary to identify potential complications early on.
• Blood type and Rh factor with antibody screening are essential to identify potential blood incompatibilities.
• Rubella immunity status, hepatitis B surface antigen, HIV testing, and syphilis screening (RPR or VDRL) are vital to detect infectious diseases that could impact the pregnancy.
• Urinalysis and urine culture are necessary to detect asymptomatic bacteriuria, which can lead to serious complications if left untreated.
• Cervical screening for gonorrhea and chlamydia is important to identify and treat sexually transmitted infections that could affect the pregnancy. Additional recommended tests include:
• Screening for gestational diabetes with either a hemoglobin A1C or glucose challenge test, as recommended by the American Diabetes Association 1, particularly in women with risk factors for diabetes.
• Thyroid stimulating hormone to identify thyroid dysfunction, which is crucial for maintaining a healthy pregnancy.
• Screening for genetic disorders such as cystic fibrosis and spinal muscular atrophy, depending on the patient's risk factors and family history. The American Diabetes Association recommends testing for undiagnosed prediabetes and diabetes at the first prenatal visit in those with risk factors using standard diagnostic criteria 1. It is also important to note that the American College of Obstetricians and Gynecologists (ACOG) recommends GDM screening in women with risk factors for diabetes 1. Overall, these tests are essential for establishing a baseline health status and identifying potential complications early on, allowing for timely interventions that improve pregnancy outcomes.

From the Research

Prenatal Screening Labs

The following labs are typically drawn at the first prenatal appointment:

• HIV screening 2, 3, 4, 5, 6
• Syphilis screening 2, 3, 4, 5, 6
• Hepatitis B screening 2, 3, 4, 5, 6
• Rubella screening 4
• Group B streptococcus (GBS) screening 4
• Complete blood count (CBC) and blood type 2
• Urine culture and sensitivity 2

Rationale for Screening

These labs are drawn to:

• Identify potential infections that could affect the mother or baby 2, 3, 4, 5, 6
• Determine the mother's immune status to certain diseases 4
• Identify any potential risks to the baby, such as congenital syphilis or HIV 3, 5
• Provide appropriate treatment and prevention measures to reduce the risk of transmission to the baby 2, 3, 4, 5, 6

Timing of Screening

Screening for these infections is typically performed at the first prenatal visit, with additional screenings performed as needed based on the mother's risk factors and medical history 2, 3, 4, 5, 6.