Society for Maternal-Fetal Medicine Consult Series #76: Cancer in pregnancy

Approximately one in 1000 pregnancies is complicated by the diagnosis of cancer each year, and the incidence of cancer among reproductive-age individuals is increasing. Management of a pregnant person with cancer can be complex and warrants a multidisciplinary approach to care. Recent data have demonstrated reassuring outcomes for pregnant persons and their offspring after treatment of many types of cancer in pregnancy. Treatment of cancer in pregnancy must be individualized based on the specific type and stage of cancer, gestational age at diagnosis, and the patient's desire to continue the pregnancy. This document aims to aid clinicians by summarizing the principles of diagnosing cancer in pregnancy and counseling patients about their reproductive and treatment options. It provides current, evidence-based recommendations for the medical and obstetrical management of patients with cancer. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we suggest that ultrasonography and non-contrast magnetic resonance imaging (MRI) be used as first-line imaging techniques in the evaluation of a pregnant person with suspected cancer (GRADE 2B); (2) although non-contrast MRI and ultrasonography are first-line diagnostic imaging modalities in pregnancy, we recommend that computed tomography (CT) with or without contrast, gadolinium contrast for MRI, and fluorine-18-fluorodeoxyglucose positron emission tomography plus CT (18-FDG-PET/CT) not be withheld from a pregnant person if clinically indicated (GRADE 1C); (3) we recommend initiating thromboprophylaxis for all patients with active hematological or gynecological cancers during pregnancy and considering thromboprophylaxis for all patients with nonhematological or nongynecological cancers during pregnancy, based on individual risk factors (GRADE 1C); (4) we recommend that surgery for the treatment of cancer not be delayed or withheld from a pregnant patient at any gestational age in pregnancy (GRADE 1C); (5) we recommend that chemotherapy generally be administered after 12 weeks of gestation, provided that the patient desires to continue the pregnancy and that delaying treatment until after 12 weeks of gestation is not expected to significantly change the pregnant patient's prognosis compared with initiating treatment immediately after diagnosis (GRADE 1C); (6) to improve long-term neurodevelopmental outcomes of children exposed to chemotherapy in utero, we suggest avoiding clinician-initiated preterm delivery when possible (GRADE 2C); (7) we recommend intravenous methylprednisolone, 62.5 mg (corresponding to 10 mg of dexamethasone), or oral prednisolone, 30 mg (corresponding to 6 mg of dexamethasone), as first-line therapy for chemotherapy-induced nausea when corticosteroids are indicated (GRADE 1B); (8) we recommend serial fetal growth surveillance every 3–4 weeks in pregnancies with an active cancer diagnosis, regardless of treatment (GRADE 1C); (9) we recommend initiation of antenatal fetal surveillance starting at 32 weeks of gestation in pregnancies with an active cancer diagnosis, regardless of treatment, unless indicated earlier for maternal or fetal reasons (GRADE 1C); (10) we recommend that planned delivery prior to 37 weeks of gestation in pregnant patients with cancer generally be avoided unless indicated for medical or obstetrical reasons (GRADE 1C); (11) we recommend that chemotherapy treatment generally be stopped by 34 weeks of gestation to allow 3–4 weeks for recovery of myelosuppression before spontaneous labor or planned delivery, except for weekly paclitaxel, which can be administered up to 35 or 36 weeks, as only 1–2 weeks are necessary for recovery before delivery (GRADE 1C); (12) we recommend that the mode of delivery be determined by routine obstetrical indications for most patients with cancer in pregnancy (GRADE 1C); (13) we recommend a placental pathology examination in all cases of cancer during pregnancy, regardless of cancer type or treatment (GRADE 1C); (14) we recommend that cancer be considered as part of the differential diagnosis for pregnant patients with multiple chromosomal aneuploidies or single autosomal monosomy detected by cell-free DNA screening that is discordant with fetal findings (GRADE 1C).