What hormone levels should be checked after a miscarriage to evaluate reproductive health?

Hormone Levels to Check After Miscarriage

After a miscarriage, the primary hormone to monitor is serial serum beta-hCG (human chorionic gonadotropin) measured at least every 2 weeks until normalization, with additional evaluation of thyroid function (TSH) and prolactin if recurrent miscarriage is present or suspected. 1, 2

Essential Hormone Monitoring

Beta-hCG (Primary Marker)

• Measure serum beta-hCG at least once every 2 weeks until levels normalize (typically <5 mIU/mL) to confirm complete resolution and exclude retained products of conception or gestational trophoblastic disease 1, 3
• Serial measurements are critical because a single hCG value has limited diagnostic utility 1
• Plateauing hCG levels (defined as <15% change over 48 hours for two consecutive measurements) or rising levels indicate potential complications requiring further evaluation 1, 4
• After complete miscarriage, most urine pregnancy tests become negative within 2 weeks, though serum hCG can persist for several weeks 4

Thyroid Function

• Check TSH levels, particularly in women with recurrent miscarriage, as thyroid dysfunction is significantly associated with pregnancy loss 2
• TSH levels are significantly lower in women with recurrent miscarriage of unknown cause compared to those with identified causes (P = 0.031) 2

Prolactin

• Measure prolactin levels if recurrent miscarriage is present, especially when polycystic ovary syndrome is suspected 2
• Hyperprolactinemia is significantly elevated in recurrent miscarriage patients with polycystic ovaries (P = 0.048) 2

Additional Hormones for Recurrent Miscarriage Evaluation

Ovarian Reserve Markers (If Planning Future Pregnancy)

• Anti-Müllerian hormone (AMH) can be measured to assess ovarian reserve, as severely diminished levels (AMH <0.7 ng/ml) are associated with slightly higher miscarriage risk in subsequent pregnancies 5
• Day 3 FSH levels may be considered alongside AMH for comprehensive ovarian reserve assessment 5
• These markers help stratify risk for future pregnancies but do not change immediate post-miscarriage management 5

Progesterone and Estradiol (Limited Utility Post-Miscarriage)

• Progesterone and estradiol levels are not routinely recommended for post-miscarriage evaluation as they have limited diagnostic value after pregnancy loss has occurred 6, 7
• These hormones are more useful for predicting miscarriage risk during ongoing early pregnancy (5-9 weeks gestation) rather than after miscarriage 8, 7
• Progestogen supplementation after recurrent miscarriage shows little to no effect on preventing future pregnancy loss (RR 0.91,95% CI 0.76-1.07) 6

Critical Clinical Pitfalls

False-Positive hCG Results

• If hCG results don't fit the clinical picture, measure hCG using a different assay, as different assays detect varying hCG isoforms and can produce false-positive results 1
• A negative urine hCG with positive serum hCG suggests assay-interfering molecules; reference laboratories can perform testing with blocking agents 5, 1

Special Consideration: Molar Pregnancy

• If molar pregnancy is diagnosed, hCG monitoring must continue for up to 6 months due to risk of gestational trophoblastic neoplasia 5, 1, 4
• For partial molar pregnancy, one additional normal hCG value is required before discharge from monitoring 5, 1
• For complete molar pregnancy, monthly hCG monitoring for up to 6 months is mandatory 5, 1, 4

When to Suspect Complications

• Persistent elevation or rising hCG after initial decline suggests retained products of conception or, rarely, gestational trophoblastic disease 1, 4
• Approximately 5.9% of women with apparent complete miscarriage based on history and ultrasound alone have an underlying ectopic pregnancy, necessitating hCG follow-up 3

Practical Algorithm

1. Immediately post-miscarriage: Obtain baseline serum beta-hCG 1, 3
2. At 2 weeks: Repeat serum beta-hCG to assess decline 1, 4
3. Continue every 2 weeks: Until hCG <5 mIU/mL 1, 3
4. If recurrent miscarriage (≥2 losses): Add TSH and prolactin to initial workup 2
5. If planning future pregnancy: Consider AMH and day 3 FSH for ovarian reserve assessment 5
6. If molar pregnancy: Extend monitoring to 6 months with specific protocols 5, 1, 4