Obstetric Outcomes After Chemotherapy in Pregnancy [ID 2683556]

INTRODUCTION: Cancer affects approximately 1 in 1,000 pregnancies; limited data exist to guide clinical decision making and counseling regarding chemotherapy. We investigated the obstetric outcomes of patients who received chemotherapy for cancer in pregnancy at a large county hospital. METHODS: In this retrospective IRB-approved study, patients diagnosed with cancer prior to or during pregnancy from May 2009 to May 2023 were identified. Those who received chemotherapy in pregnancy were included. Type of cancer, chemotherapeutic agents, and obstetric outcomes were obtained from the electronic medical record. RESULTS: Of 22 patients who initiated or continued chemotherapy, seven had a cancer diagnosis prior to pregnancy. Fifteen were diagnosed in pregnancy, at an average gestational age of 15.5 weeks. Average maternal age was 30.5 years. Hematologic (36%) and breast (32%) cancers were most common. Four terminated pregnancy and 18 continued pregnancy. Chemotherapy initiation occurred at an average of 21.2 weeks. Most patients received alkylating agents or antitumor antibiotics, and only one required antepartum admission for chemotherapy-related complications. Patients delivered at an average of 35.6±3.0 (29–41) weeks and 9/18 (50%) patients delivered prior to 37 weeks. Severe fetal growth restriction (less than third percentile) occurred in 6/18 (33%) patients; one had a history of fetal growth restriction in a prior pregnancy. There were no neonatal deaths or congenital malformations. CONCLUSION: While high rates of fetal growth restriction and preterm birth were observed, chemotherapy was well tolerated in pregnancy and all non-terminated pregnancies delivered viable infants in the third trimester. Chemotherapy can be administered in pregnancy with counseling regarding neonatal risks.