Background Administration of chemotherapy during pregnancy is often delayed, while preterm delivery is common. If in utero exposure to chemotherapy is associated with adverse pediatric outcomes, it is unknown whether that relationship is directly attributable to the chemotherapy or is mediated by preterm birth. Methods Cases were identified from Canadian cancer registries and administrative data in Alberta, British Columbia, and Ontario, 2003-2017, with follow-up until 2018. The primary exposure was receipt of chemotherapy during pregnancy. Severe neonatal morbidity and mortality (SNM-M), neurodevelopmental disorders and disabilities (NDDs) and pediatric complex chronic conditions (PCCC) reflected short- and long-term pediatric outcomes. Modified Poisson and Cox proportional hazard regression models generated adjusted risk ratios (RR) and hazard ratios (HR), respectively. The influence of preterm birth on the association between exposure to chemotherapy in pregnancy and each study outcome was explored using mediation analysis. Results Of the 1150 incident cases of cancer during pregnancy, 142 (12.3%) received chemotherapy during pregnancy. Exposure to chemotherapy in pregnancy was associated with a higher risk of SNM-M (RR 1.67, 95% CI: 1.13-2.46), but not NDD (HR 0.93, 95% CI: 0.71-1.22) or PCCC (HR 0.96, 95% CI: 0.80-1.16). Preterm birth <34 and <37 weeks mediated 75.8% and 100% of the observed association between chemotherapy and SNM-M, respectively. Conclusions Most children born to people with cancer during pregnancy appear to have favourable long-term outcomes, even following exposure to chemotherapy in pregnancy. However, preterm birth is quite common, and may contribute to increased rates of adverse neonatal outcomes.

中文翻译：

---

妊娠期癌症化疗和不良儿科结局： 一项基于人群的队列研究


背景 妊娠期化疗的实施经常延迟，而早产很常见。如果宫内化疗暴露与不良儿科结局相关，则尚不清楚这种关系是直接归因于化疗还是由早产介导。方法 从 2003-2017 年阿尔伯塔省、不列颠哥伦比亚省和安大略省的加拿大癌症登记处和行政数据中确定病例，并随访至 2018 年。主要暴露是在怀孕期间接受化疗。严重新生儿发病率和死亡率 （SNM-M） 、神经发育障碍和残疾 （NDD） 以及儿科复杂慢性病 （PCCC） 反映了短期和长期儿科结局。改良的 Poisson 和 Cox 比例风险回归模型分别生成调整后的风险比 （RR） 和风险比 （HR）。使用中介分析探讨早产对妊娠期化疗暴露与每项研究结果之间关联的影响。结果 1150 例妊娠期癌症发病病例中，142 例 （12.3%） 在妊娠期接受化疗。妊娠期接受化疗与 SNM-M 风险较高 （RR 1.67， 95% CI： 1.13-2.46） 相关，但与 NDD （HR 0.93， 95% CI： 0.71-1.22） 或 PCCC （HR 0.96， 95% CI： 0.80-1.16） 无关。早产 <34 和 <37 周分别介导了观察到的化疗与 SNM-M 之间关联的 75.8% 和 100%。结论 癌症患者在妊娠期所生的大多数孩子似乎具有良好的长期结局，即使在妊娠期接受化疗后也是如此。然而，早产很常见，并可能导致新生儿不良结局发生率增加。