Maternal death by cancer in pregnancy: A descriptive study of the International Network on Cancer, Infertility and Pregnancy.

Objective: To characterise pregnant women diagnosed with primary or recurrent cancer who died during pregnancy, during delivery or within 1 year postpartum.

Design: A descriptive study.

Setting: The registry of the International Network on Cancer, Infertility and Pregnancy (INCIP).

Population: Women diagnosed with cancer during pregnancy between 2000 and 2022.

Methods: Using the INCIP registry database, we compared the characteristics of all women with cancer who died during pregnancy, delivery or within 1 year postpartum with those of all women with cancer who survived the first year postpartum.

Main outcome measures: Maternal and tumour characteristics and obstetrical and neonatal outcomes.

Results: Of the 2359 women registered in INCIP, there were 131 cases (5.6%) of maternal mortality. Lung cancer (9/14, 64.3% of all registered women with lung cancer), gastro-oesophageal cancer (13/21, 61.9%) and acute leukaemia (17/105, 16.2%) had the highest rates of maternal mortality. Maternal mortality was associated with fewer live births compared with the control group without maternal mortality (99/131, 75.6%, vs 1952/2163, 90.0%; P < 0.001), more elective caesarean sections (64/104, 60.4%, vs 756/1836, 41.2%; P < 0.001) and a lower gestational age at (induced) delivery (34.0 vs 37.1 weeks; P < 0.001), resulting in more preterm births.

Conclusions: Maternal mortality occurred in 5.6% of cancer-in-pregnancy cases and is associated with adverse perinatal outcomes.