# Cancer during pregnancy

Source: https://onco.cc/terms/cancer-in-pregnancy/  
OnCo record `cancer-in-pregnancy` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

About 1 in 1,000 pregnancies is complicated by cancer, most often breast, cervical, lymphoma, melanoma or leukaemia. Most chemotherapy is safe after the first trimester, surgery is safe throughout, and ending the pregnancy does not improve the mother's outcome.

## Summary

Incidence is rising with later childbearing. Principles (INCIP, ESMO 2013/2019 guidelines): staging with ultrasound and non-contrast MRI, avoid radiotherapy to the abdomen and most targeted/immune agents; surgery any trimester; anthracycline- and taxane-based chemotherapy from 14 weeks with delivery ≥3 weeks after the last cycle and not before 37 weeks where possible; no chemotherapy in the first trimester (malformation risk). The INCIP cohort showed children exposed in utero have normal cognitive and cardiac development at 3 and 6 years (Amant, NEJM 2015), with prematurity, not chemotherapy, driving outcomes. Trastuzumab (oligohydramnios), endocrine therapy, immunotherapy, TKIs and methotrexate are contraindicated or avoided. Pregnancy-associated breast cancer within a few years postpartum has worse biology. Placental metastasis is rare (melanoma most common).

## Fields

- Kind: Term
- Last checked: 2026-09-08
- Tags: gap-fill

## Sources

- ESMO cancer in pregnancy guideline: https://doi.org/10.1093/annonc/mdt199
- INCIP (Amant, NEJM 2015): https://doi.org/10.1056/NEJMoa1508913
- INCIP network: https://www.cancerinpregnancy.org/

## Connected records

- cancers: [Adolescent and young adult cancers (ages 15 to 39)](https://onco.cc/cancers/aya-cancers/), [Cervical cancer](https://onco.cc/cancers/cervical/), [Gestational trophoblastic neoplasia](https://onco.cc/cancers/gestational-trophoblastic/), [Hodgkin lymphoma](https://onco.cc/cancers/hodgkin-lymphoma/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Melanoma](https://onco.cc/cancers/melanoma/)
- technologies: [Oncofertility and fertility preservation](https://onco.cc/technologies/fertility-preservation/)
- terms: [Adolescent and young adult (AYA) oncology](https://onco.cc/terms/aya-oncology/)
- key papers: [Cancer, pregnancy and fertility: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up](https://onco.cc/key-papers/paper-peccatori-ann-oncol/), [Pediatric Outcome after Maternal Cancer Diagnosed during Pregnancy](https://onco.cc/key-papers/paper-amant-n-engl-j-med/)

---
JSON: https://onco.cc/api/v1/entities/cancer-in-pregnancy.json