Pregnancy

ACOG-endorsed guidance outlines key steps for managing cancer in pregnancy

March 26, 2026

New ACOG‑endorsed guidance from the Society for Maternal‑Fetal Medicine provides evidence‑based recommendations for diagnosing and managing cancer during pregnancy, now affecting about 1 in 1,000 pregnancies.

Recommendations

1. Use ultrasonography and non-contrast MRI as first-line imaging for suspected cancer in pregnancy (GRADE 2B).
2. Do not withhold CT (± contrast), gadolinium-enhanced MRI, or 18‑FDG‑PET/CT if clinically indicated (GRADE 1C).
3. Initiate thromboprophylaxis for all patients with active hematologic or gynecologic cancers during pregnancy and consider it for others based on risk factors (GRADE 1C).
4. Do not delay or withhold cancer surgery at any gestational age when indicated (GRADE 1C).
5. Administer chemotherapy after 12 weeks’ gestation when feasible and consistent with maternal prognosis and patient goals (GRADE 1C).
6. Avoid clinician-initiated preterm delivery when possible to support long-term neurodevelopment after in utero chemotherapy exposure (GRADE 2C).
7. Use corticosteroids appropriately for chemotherapy-induced nausea (IV methylprednisolone or oral prednisolone equivalents) when indicated (GRADE 1B).
8. Perform serial fetal growth surveillance every 3 to 4 weeks with an active cancer diagnosis (GRADE 1C).
9. Begin antenatal fetal surveillance at 32 weeks’ gestation with active cancer, unless earlier indicated (GRADE 1C).
10. Generally avoid planned delivery prior to 37 weeks’ gestation unless medically or obstetrically indicated (GRADE 1C).
11. Stop most chemotherapy by 34 weeks’ gestation (weekly paclitaxel may continue to 35–36 weeks) to allow marrow recovery before delivery (GRADE 1C).
12. Determine mode of delivery based on routine obstetric indications for most patients (GRADE 1C).
13. Obtain placental pathology examination in all cases of cancer during pregnancy (GRADE 1C).
14. Include cancer in the differential when cfDNA screening shows multiple aneuploidies or single autosomal monosomy discordant with fetal findings (GRADE 1C).

Source:

Society for Maternal-Fetal Medicine (SMFM); Gulersen M, et al. (2026, March 12). Pregnancy. Society for Maternal-Fetal Medicine Consult Series #76: Cancer in pregnancy. https://obgyn.onlinelibrary.wiley.com/doi/10.1002/pmf2.70221