Guiding the Diagnosis and Treatment of Cancer During Pregnancy

Cancer during pregnancy is rare but increasingly recognized as maternal age rises and non-invasive prenatal testing becomes more common, according to research published in the International Journal of Gynecology and Obstetrics.

Estimating the global incidence remains challenging due to limited data from international registries and inconsistent reporting. According to the International Network of Cancer, Infertility, and Pregnancy, breast cancer, hematologic cancers, melanoma and cervical cancer are the most frequently diagnosed malignancies during pregnancy. Colorectal cancer and lymphomas are often detected at more advanced stages. Pregnancy-associated cancer, which is defined as cancer diagnosed during pregnancy or within one year after delivery, occurs in approximately one in 1,000 pregnancies.

According to U.K. data, a maternal mortality rate of 0.87 per 100,000 pregnancies (approximately 3% of all maternal deaths) was reported among women with cancer during pregnancy or within six weeks of delivery. In a separate analysis of 2,359 women with cancer, maternal mortality was 5.6% (131 women). These statistics highlight the importance of timely diagnosis and management, especially given the potential for delayed detection due to overlapping pregnancy symptoms such as nausea, fatigue, and breast changes.

Multidisciplinary Care Ensures Safe Maternal and Fetal Outcomes

Managing cancer during pregnancy requires a multidisciplinary team approach, according to the International Federation of Gynecology and Obstetrics (FIGO). In settings where full multidisciplinary team expertise is unavailable, shared care with regional centers or consulting support networks is advised.

Pregnancy should not delay investigations for suspected disease. Ultrasound and magnetic resonance imaging (MRI) are preferred for diagnosis due to their safety profile, while low-dose computed tomography (CT) or positron emission tomography (PET) scans may be used when clinically indicated. Tissue biopsies and sentinel lymph node procedures can be safely performed, with adjustments for gestational age to reduce fetal risk. Tumor markers can be monitored, although physiological changes in pregnancy may affect their interpretation.

Treatment Options and Supportive Care During Pregnancy

Treatment planning considers both maternal health and fetal well-being. Surgery is generally safe during pregnancy, with early second trimester preferred to minimize miscarriage risk, and laparoscopic approaches favored when feasible. Radiotherapy is typically avoided, especially for pelvic tumors, but may be carefully administered in select cases with fetal shielding and dose adjustments. Chemotherapy is generally safe after the first trimester, using standard regimens with monitoring for maternal toxicity and fetal growth. Certain targeted therapies may be used selectively, while others, are contraindicated.

Supportive care is an integral component, including antiemetics, growth factors and analgesics. Venous thromboembolism (VTE) prophylaxis is recommended for all pregnant women with active cancer, typically using low molecular weight heparin until at least six weeks postpartum. Vaccinations are safe and advised, with live vaccines contraindicated during pregnancy.

FIGO best practice advice underscores that maternal treatment and continuation of pregnancy should generally be prioritized over medically induced preterm delivery. Decisions regarding investigations, therapy and supportive care should involve both the mother and her care team, with careful documentation of risk/benefit considerations.

Managing Cancer During Pregnancy: Postnatal Care Guidelines

Pregnant women with cancer experience higher risks of maternal and fetal complications, including preterm birth, fetal growth restriction, stillbirth, cesarean delivery, VTE and maternal morbidity. Careful surveillance is essential, including ultrasounds for fetal growth, Doppler assessment for anemia, cervical monitoring and low-dose aspirin for high-risk pre-eclampsia. Moreover, conventional first-trimester screening and detailed fetal anatomical assessment are recommended.

Delivery planning should aim for a minimum of 37 weeks into pregnancy and beyond (typically over 38 weeks), with vaginal delivery preferred unless contraindicated by tumor location or maternal condition. A washout period after chemotherapy reduces neonatal myelosuppression. Placental histology is recommended to evaluate for metastases; neonatal assessment should monitor for toxicity, cardiotoxicity, auditory deficits and long-term development.

Postnatal care emphasizes timely maternal treatment initiation, contraception counseling, and breastfeeding guidance, balancing safety with maternal well-being. Psychological support and family counseling are crucial throughout, according to the research.

Researchers conclude their investigation by stating: “Caring for pregnant women with cancer poses a complex medical, ethical, legal, and psychosocial challenge, highlighting the need for a multidisciplinary approach to optimize care. ... It is important to empower the pregnant and recently pregnant women to have the same quality of care as any non-pregnant person, to be properly informed, and to be involved in all decisions relating to their care.”

Reference

1. “Cancer in pregnancy: FIGO Best practice advice and narrative review,” by Dr. Surabhi Nanda, et al. International Journal of Gynecology & Obstetrics.

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