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

Abstract 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.