Adverse Birth Outcomes Among Offspring Born to Women Diagnosed With Cancer: A Population-Based Cohort Study

Abstract

Background: The prevalence of maternal cancer and its influence on adverse birth outcomes (ABOs) are important for prenatal care and oncological management. The incidence and cancer types before, during, and after pregnancy, and the association between cancers and ABOs were assessed. Methods: Birth registry and cancer registry data were linked, and 16,475 children born to mothers with a cancer diagnosis were identified. Multiple logistic regression was used to estimate the ABOs risks according to the diagnosis period and cancer types. Findings: The incidence of pregnancy-associated cancer was 1.3/1000 pregnancies, with thyroid (46%), cervical (14%), and breast cancers (8%) being the commonest. Increased risks of preterm birth (Odds ratios [OR]=1·82, 95% CI:1·51–2·19) and low birth weight (LBW, OR=1·90, 95%CI: 1·51–2·19) were associated with cancer diagnosed in middle and late pregnancy. Increased risks of birth defects (OR=2·44, 95% CI: 1·00–5·92) were associated with cancer diagnosed in the first trimester. There was a positive association of birth defects and preterm birth with pregnancy-associated(OR=1·79, 95% CI: 1·01–3·17) and pre-gestational (OR=1.31, 95% CI: 1·07–1·61) thyroid cancer, respectively. Interpretation: The increased risk of prenatal cancer-associated preterm birth and LBW was mainly due to iatrogenic preterm delivery. The higher incidence of thyroid cancer and the associated increased risk of birth defects and preterm birth suggest more attention should be paid to prudent therapy and thyroid function monitoring during pregnancy. Funding: National Natural Science Foundation of China (82003486) and the Fifth Round of Three-Year Public Health Action Plan of Shanghai, China (GWV-10.1-XK08). Declaration of Interest: The authors declare that they have no competing interests. Ethical Approval: This study was approved by the Ethics Review Committee of the Shanghai Municipal Center for Disease Control and Prevention.