Incidence, and maternal and neonatal outcomes following pregnancy-associated colorectal cancer: A population-based linked data study.

Aim: The study aimed to describe the incidence of pregnancy-associated colorectal cancer (PACRC) in New South Wales (NSW), Australia, and to examine the perinatal outcomes of women with PACRC and their babies.

Methods: A population-based cohort study was conducted using linked data from NSW. The study group comprised all women diagnosed with colorectal cancer during pregnancy (gestational CRC) or postpartum (postpartum CRC). Women who gave birth without cancer during pregnancy or postpartum formed the comparison group (no-cancer group).

Results: A total of 123 women were diagnosed with PACRC (22 gestational, 101 postpartum), and 1 786 078 women were in the no-cancer group. The incidence of PACRC was 6.9/100 000 women giving birth. From 1994 to 2013, the incidence significantly increased even when adjusting for maternal age (adjusted increase of 5.8% per year). Women with gestational CRC had significantly higher odds of severe maternal complications (AOR 29.27, 95% CI: 11.18-76.63) and were more likely to give birth by labor induction or no-labor caesarean section (AOR 4.39, 95% CI: 1.50-12.84) than women in the no-cancer group. Although babies born to women with gestational CRC did not experience congenital anomalies, they had higher odds of planned preterm birth (AOR 9.91, 95% CI: 1.99-49.21) and severe neonatal adverse outcomes (AOR 8.65, CI: 3.65-20.5) than babies of women without cancer.

Conclusions: The study found a significant increase in PACRC incidence in NSW over the study period, independent of maternal age. Increased interventions during gestational CRC births reflect management challenges with higher maternal and neonatal morbidities.