Chemotherapy during First Trimester Pregnancy Leading to Fetal Malformation: A Case Report with Review of Literature

Abstract Pregnancy coexisting with the diagnosis of malignancy is rare. It poses a major management dilemma to the oncologist where adequate oncology outcomes need to be weighed against the fetal well-being. Use of chemotherapy during pregnancy is determined by the type of malignancy, stage, gestational age, chemotherapy agent, and the risk of placental transfer. A 33-year-old female patient presented with a gradually progressive breast lump. After adequate workup, the patient was diagnosed with infiltrating duct carcinoma left breast (T3N0M1), with liver metastases and triple-negative breast cancer. Subsequently, the patient received detailed counseling about treatment, prognosis, and contraceptive use to avoid conception and was started on palliative chemotherapy with doxorubicin, cyclophosphamide, and docetaxel. Radiology was performed for response assessment after eight cycles of chemotherapy. It demonstrated an accidental pregnancy of 22 weeks and 4 days gestation with major malformations including corpus callosum agenesis with ventriculomegaly, skeletal dysplasia including hypoplastic upper limbs, and absent radius in one arm. The patient underwent medical termination of pregnancy and further oncology treatment as per response and standard treatment guidelines. Chemotherapy should be strictly avoided for pregnant patients in the first trimester given its teratogenic effects, leading to major fetal malformations. The use of multiple drugs makes it difficult to establish a causal role of a particular chemotherapeutic agent with specific malformation. Adequate anticonception counseling and pregnancy tests should be offered to women diagnosed with cancer who are in the reproductive age group, prior to starting chemotherapy.