What blood work is recommended for a female of reproductive age with no known medical conditions or previous fertility issues to evaluate fertility?

Recommended Blood Work for Female Fertility Evaluation

For a reproductive-age woman with no known medical conditions evaluating fertility, order anti-Müllerian hormone (AMH), day 2-3 FSH and LH, day 21 progesterone, TSH, CBC, and infectious disease screening including chlamydia, gonorrhea, syphilis, HIV, rubella, and hepatitis B. 1

Core Hormonal Assessment

Ovarian Reserve Testing

• AMH is the most reliable marker for ovarian reserve and should be measured regardless of cycle day, making it the most convenient initial test 1
• Day 2-3 FSH and LH assess both ovarian reserve and pituitary function, providing complementary information to AMH 1
• These three hormones together give the most complete picture of ovarian function and reproductive potential 1

Ovulatory Function

• Midluteal phase progesterone (day 21 of a 28-day cycle) confirms ovulation, which is essential to document even in women with regular cycles 1
• If cycles are irregular, adjust timing to approximately 7 days before expected menses 2

Thyroid Function

• TSH screening is mandatory as thyroid disorders directly affect fertility and are easily treatable 1
• Thyroid dysfunction can cause anovulation and pregnancy complications even when subclinical 1

Infectious Disease Screening

All women should be screened for sexually transmitted infections and vaccine-preventable diseases that impact pregnancy outcomes: 1

• Chlamydia and gonorrhea (can cause tubal factor infertility) 1
• Syphilis and HIV (affect pregnancy outcomes) 1
• Rubella seronegativity (vaccination needed if non-immune before conception) 1
• Hepatitis B surface antigen 1

Hematologic Assessment

• Complete blood count (CBC) identifies anemia or other hematologic abnormalities that could impact fertility and pregnancy 1
• Anemia can affect ovulation and pregnancy outcomes 1

Additional Testing for Specific Presentations

Women with Irregular Cycles or Clinical Hyperandrogenism

• Consider androgen levels (total testosterone, free testosterone), glucose tolerance testing, and insulin resistance screening to evaluate for polycystic ovary syndrome 1
• PCOS accounts for 70% of anovulatory infertility 3

Women with Recurrent Pregnancy Loss

• Karyotyping and thrombophilia testing should be considered 1

Integration with Imaging Studies

Laboratory testing should be paired with transvaginal ultrasound to evaluate ovarian morphology and antral follicle count: 1

• Ovarian volume <3 cm³ and <5 antral follicles indicate diminished ovarian reserve 1
• Ultrasound provides anatomical assessment that complements hormonal testing 4, 5
• Hysterosalpingography assesses tubal patency in women actively pursuing pregnancy 1

Critical Interpretation Points

AMH levels may fluctuate in women under 25 years, requiring cautious interpretation in younger patients 1

Do not rely on a single test result—ovarian reserve assessment requires integration of AMH, FSH, LH, and ultrasound findings for accurate interpretation 1, 4

Age is the single most important factor affecting fertility, with decline beginning at 25-30 years and accelerating after 35 years 6, 3

Timing Considerations

• Initiate evaluation earlier (before 12 months of attempting conception) if the woman is over 35 years 2, 3
• For women over 38-40 years, more aggressive evaluation and treatment may be warranted given age-related fertility decline 3