From the Guidelines
At the beginning of pregnancy, the following laboratory tests are typically ordered to assess maternal health and identify potential risks: complete blood count, blood type and Rh factor, antibody screening, urine culture, urinalysis, rubella immunity status, hepatitis B surface antigen, HIV, syphilis testing, cervical cytology, gonorrhea and chlamydia screening, tuberculosis testing, hemoglobin A1c or glucose testing, and thyroid-stimulating hormone levels. These tests are crucial for establishing baseline health parameters and identifying conditions that might require intervention during pregnancy to ensure optimal outcomes for both mother and baby 1. The specific tests ordered may vary depending on individual risk factors and medical history, but the goal is to identify potential complications early on and provide appropriate management to minimize risks. For example, women with chronic hypertension should have additional tests performed, including a full blood count, liver enzymes, serum creatinine, electrolytes, and uric acid, as well as urinalysis and microscopy, to provide a baseline reference for potential superimposed preeclampsia 1. Key laboratory tests for all pregnant women include:
- Complete blood count to check for anemia
- Blood type and Rh factor to determine if Rh immunoglobulin is needed
- Antibody screening to detect potential blood incompatibilities
- Urine culture and urinalysis to screen for asymptomatic bacteriuria and proteinuria
- Rubella immunity status to identify susceptible women who will need vaccination postpartum
- Hepatitis B surface antigen, HIV, and syphilis testing to detect infections that could affect the fetus
- Additional tests such as cervical cytology, gonorrhea and chlamydia screening, and tuberculosis testing for high-risk women
- Hemoglobin A1c or glucose testing to screen for diabetes
- Thyroid-stimulating hormone levels to detect thyroid dysfunction. It is essential to note that the specific tests and their timing may vary depending on individual circumstances, and healthcare providers should use their clinical judgment to determine the most appropriate tests for each patient 1.
From the Research
Laboratory Tests at the Beginning of Pregnancy
The following laboratory tests are typically ordered at the beginning of pregnancy:
- Complete blood count (CBC) 2
- Blood group and antibody screen 2
- Rubella antibody status 2
- Syphilis serology 2, 3
- Hepatitis B serology 2, 3
- HIV abs testing 2, 3
- Varicella testing (may be added to the first antenatal screen) 2
- Chlamydia testing (may be added to the first antenatal screen) 2
- Vitamin D testing (may be added to the first antenatal screen) 2
- Hemoglobin (Hgb) level testing to check for anemia 3
- Urine analysis to check for asymptomatic urinary tract infections 3
- Rapid plasma reagin (RPR) test for syphilis 3
- Hepatitis B surface antigen (HBsAg) test 3
- Anti-HIV antibodies test 3
Additional Testing
Additional testing may be recommended based on the patient's risk factors and medical history, such as:
- Screening for Down syndrome, other chromosomal abnormalities, and neural tube defects (recommended for all pregnant women above the age of 35 years) 2
- Gestational diabetes screening 2
- Protein detection in urine to rule out preeclampsia 2
- Group B streptococcal (GBS) infection screening (recommended at 37 weeks of pregnancy) 2
- Toxoplasmosis screening (may be recommended for pregnant women at risk of primary Toxoplasma gondii infection) 4