与既往未患乳腺癌的女性相比，乳腺癌幸存者的产科和围产期结局如何？在乳腺癌诊断后的头 2 年内怀孕的女性早产、引产和剖宫产的风险较高，而在乳腺癌诊断后 2 年后怀孕的婴儿没有观察到风险增加。最近的一项荟萃​​分析发现，乳腺癌幸存者的妊娠中剖宫产、早产、低出生体重和小于胎龄的风险较高。我们对先兆子痫或先天畸形等罕见结果知之甚少。我们进行了一项基于人群的匹配队列研究，包括 1973 年至 2017 年在瑞典生育单胞胎的所有乳腺癌幸存者，通过瑞典癌症登记处、医学出生登记册和国家乳腺癌质量登记册。乳腺癌后的每次分娩 (n = 926) 均与母亲分娩时的年龄、产次和分娩日历年份与对照组妇女队列中的 100 名新生儿进行匹配 (n = 92 490）。条件逻辑回归模型和多项回归模型估计相对风险 (RR) 的置信区间为 95%。按诊断后时间和治疗类型进行亚组分析。既往乳腺癌与较高的引产风险 (RR; 1.3, 1.0-1.6)、极早产风险 (RR; 1.8, 1.1-3.0) 和计划早产风险相关出生（RR；1.6、1.0-2.4）。乳腺癌诊断后 1 年内怀孕的女性剖宫产 (RR; 1.7, 1.0-2.7)、极早产 (RR; 5.3, 1.9-14.8) 和低出生体重 (RR; 2.7, 1.4-5.2) 的风险较高），而妊娠妇女的引产风险（RR；1.8、1.1-2.9）、中度早产（RR；2.1、1.2-3.7）和计划早产（RR；2.5、1.1-5.7）风险较高诊断后的第二年。乳腺癌诊断后 2 年后受孕的女性与对照组有相似的产科风险。由于无法获得治疗结束日期的信息，因此使用诊断日期和受孕日期之间的时间作为代理，这并不能完全反映自治疗结束以来时间的影响。此外，在长期研究期间，治疗方法和临床建议发生了变化，这可能会影响乳腺癌幸存者的生育模式。乳腺癌幸存者不良产科结局的风险仅限于诊断后 2 年内怀孕的婴儿。由于家庭建设对许多年轻乳腺癌患者具有重要意义，因此这些发现对于告知乳腺癌幸存者和临床医生未来的生殖结果尤其重要。这项工作得到了瑞典癌症协会（拨款号 22-2044 Pj A.L.V.J.）、Karolinska 的支持研究所基金会（拨款号：2022-01696 F.E.L.、2022-01559 A.L.V.J.）和瑞典研究理事会（拨款号：2021-01657 A.L.V.J.）。 K.A.R.-W.得到瑞典癌症协会 (20 0170 F) 和 Radiumhemmets 研究基金会 2020-2026 年临床研究人员的资助。作者声明他们没有利益冲突。N/A。© 作者 2024。由牛津大学出版社代表欧洲人类生殖和胚胎学学会出版。

What are the obstetric and perinatal outcomes in births to breast cancer survivors compared to women without previous breast cancer?Women who conceived during the first 2 years following a breast cancer diagnosis had a higher risk for preterm birth, induced delivery, and cesarean section, while no increased risks were observed in births conceived later than 2 years after a breast cancer diagnosis.A recent meta-analysis found higher risks of cesarean section, preterm birth, low birthweight, and small for gestational age in pregnancies among breast cancer survivors. Less is known about rarer outcomes such as pre-eclampsia or congenital malformations.We conducted a population-based matched cohort study including all breast cancer survivors who gave birth to singletons 1973-2017 in Sweden, identified through linkage between the Swedish Cancer Register, the Medical Birth Register, and the National Quality Register for Breast Cancer.Each birth following breast cancer (n = 926) was matched by maternal age at delivery, parity, and calendar year at delivery to 100 births in a comparator cohort of women (n = 92 490). Conditional logistic and multinomial regression models estimated relative risks (RR) with 95% CI. Subgroup analyses by time since diagnosis and type of treatment were performed.Previous breast cancer was associated with higher risks of induced delivery (RR; 1.3, 1.0-1.6), very preterm birth (RR; 1.8, 1.1-3.0), and planned preterm birth (RR; 1.6, 1.0-2.4). Women who conceived within 1 year after breast cancer diagnosis had higher risks of cesarean section (RR; 1.7, 1.0-2.7), very preterm birth (RR; 5.3, 1.9-14.8), and low birthweight (RR; 2.7, 1.4-5.2), while the risks of induced delivery (RR; 1.8, 1.1-2.9), moderately preterm birth (RR; 2.1, 1.2-3.7), and planned preterm birth (RR; 2.5, 1.1-5.7) were higher in women who conceived during the second year after diagnosis. Women who conceived later than 2 years after breast cancer diagnosis had similar obstetric risks to their comparators.As information on the end date of treatment was unavailable, the time between the date of diagnosis and conception was used as a proxy, which does not fully capture the effect of time since end of treatment. In addition, treatments and clinical recommendations have changed over the long study period, which may impact childbearing patterns in breast cancer survivors.Risks of adverse obstetric outcomes in breast cancer survivors were confined to births conceived within 2 years of diagnosis. As family building holds significance for numerous young breast cancer patients, these findings are particularly important to inform both breast cancer survivors and clinicians about future reproductive outcomes.This work was supported by the Swedish Cancer Society (grant number 22-2044 Pj A.L.V.J.), Karolinska Institutet Foundations (grant number: 2022-01696 F.E.L., 2022-01559 A.L.V.J.), and the Swedish Research Council (grant number: 2021-01657 A.L.V.J.). K.A.R.-W. is supported by grants from the Swedish Cancer Society (20 0170 F) and the Radiumhemmets Research Foundations for clinical researchers 2020-2026. The authors declare that they have no conflicts of interest.N/A.© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.