Maternal comorbidity and adverse perinatal outcomes in survivors of adolescent and young adult cancer: A cohort study

Abstract

Objective To evaluate risks of preterm birth (PTB) and severe maternal morbidity (SMM) in female survivors of adolescent and young adult cancer and assess maternal comorbidity as a potential mechanism. To determine whether associations differ by use of assisted reproductive technology (ART). Design Retrospective cohort. Setting Commercially insured females in the USA. Sample Females with live births from 2000–2019 within a de‐identified US administrative health claims data set. Methods Log‐binomial regression models estimated relative risks of PTB and SMM by cancer status and tested for effect modification. Causal mediation analysis evaluated the proportions explained by maternal comorbidity. Main Outcome Measures PTB and SMM. Results Among 46 064 cancer survivors, 2440 singleton births, 214 multiple births and 2590 linked newborns occurred after cancer diagnosis. In singleton births, the incidence of PTB was 14.8% in cancer survivors versus 12.4% in females without cancer (aRR 1.19, 95% CI 1.06–1.34); the incidence of SMM was 3.9% in cancer survivors versus 2.4% in females without cancer (aRR 1.44, 95% CI 1.13–1.83). Cancer survivors had more maternal comorbidities before and during pregnancy; 26% of the association between cancer and PTB and 30% of the association between cancer and SMM was mediated by maternal comorbidities. Tests for effect modification of cancer status on perinatal outcomes by ART were non‐significant. Conclusions Preterm birth and SMM risks were modestly increased after cancer. Significant proportions of elevated risks may result from increased comorbidities. ART did not significantly modify the association between adolescent and young adult cancer and adverse perinatal outcomes. The prevention and treatment of comorbidities provides an opportunity to improve perinatal outcomes among cancer survivors.

Risk of adverse birth outcomes after adolescent and young adult cancer

“…US-based studies are fewer in number but have often had similar findings. A recent study of commercially insured women from across the United States reported a slightly but significantly higher risk of preterm delivery among births to AYA cancer survivors (N = 2654) compared to births to women without cancer (RR = 1.19; 95% CI: 1.06 to 1.34) ( 15 ). Similarly, in our prior analyses using statewide birth certificate and cancer registry data in North Carolina, births to women diagnosed with AYA cancer before the start of pregnancy were 1.23 (95% CI: 1.07 to 1.43) and 1.36 (95% CI: 1.16 to 1.59) times as likely to be preterm and LBW, respectively, as births to cancer-free women ( 16 ).…”