Obstetric and perinatal outcomes in women with previous breast cancer: a nationwide study of singleton births 1973-2017.

Study Question: What are the obstetric and perinatal outcomes in births to breast cancer survivors compared to women without previous breast cancer?

Summary Answer: 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.

What Is Known Already: 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.

Risk of obstetric and perinatal complications in women presenting with breast cancer during pregnancy and the first year postpartum in Sweden 1973-2017: A population-based matched study.

Introduction: For women presenting with breast cancer during pregnancy, treatment guidelines were historically restricted to only surgical treatment. Over the past decades, chemotherapy administered during pregnancy has been gradually introduced. Although breast cancer treatments during ongoing pregnancy have been deemed safe, detailed information on potential obstetric risks is lacking.