Taxane Use for Breast Cancer in Pregnancy: Neonatal Follow-Up Of Infants with Positive Detection of Intact Paclitaxel and Metabolites in Meconium at Birth

Abstract Paclitaxel is often excluded during pregnancy for women with breast cancer due to limited neonatal follow-up. We confirmed in utero fetal Paclitaxel exposure for 8 newborns. Birth details and follow-up to 36 months of age is reported. Meconium samples from newborns exposed to chemotherapy were screened by liquid chromatography-high resolution mass spectrometry while blinded to maternal treatment during pregnancy. Newborn information at birth and annually was obtained. Mean gestational age (GA) at cancer diagnosis and start of chemotherapy was 8.7 + 6.2 weeks and 17.1 +/- 3.5 weeks. Paclitaxel was started at a mean GA of 27.0 +/- 5.8 weeks. Paclitaxel followed Doxorubicin/Cyclophosphamide in 6 cases, 5-Fluouracil/Doxorubicin/Cyclophosphamide in 1, and was used alone in 1. Mean number of days between Paclitaxel and birth was 23 +/- 15. Identification of Paclitaxel and/or metabolites was made in all taxane exposed samples. Birthweight was < 10% for GA in 3 infants. Three anomalies occurred: hip dysplasia and mitral valve stenosis. The 3rd child was diagnosed with Cleidocranial Dysostosis, a familial anomaly. Mean age at pediatric follow-up is 18.7 + 9.3 months. Pediatricians report eczema and recurrent otitis media in 1 child, iron deficiency anemia and sinusitis in 2. One child is < 10% for height and weight at 15 months. All are meeting developmental milestones at median age of 18.7 months, range: 6–36 months. Conclusion: Up to 3 years of age, follow-up of neonates exposed to Paclitaxel in utero is reassuring. Continued observation of neonatal development is essential.