Pregnancy Outcomes After in Utero Exposure to Immune Checkpoint Inhibitors

Area of Science:

• Oncology
• Immunology
• Reproductive Medicine

Background:

• Immune checkpoint inhibitors (ICIs) are revolutionizing cancer treatment.
• Their use in reproductive-age patients raises critical questions about pregnancy outcomes.
• Data on ICI exposure during pregnancy and its effects are limited.

Purpose of the Study:

• To describe maternal and fetal outcomes following in-utero exposure to immune checkpoint inhibitors.
• To conduct a comprehensive literature review of reported ICI pregnancies.
• To inform clinical practice regarding contraception and counseling for patients on ICIs.

Main Methods:

• Retrospective chart review of patients exposed to ICIs during pregnancy at a major cancer center.
• Narrative literature review of PubMed-identified cases of ICI exposure during pregnancy.
• Collection of clinical data on cancer type, treatment timing, pregnancy course, and maternal/neonatal outcomes.

Main Results:

• Two institutional cases: one healthy live birth after early pembrolizumab exposure, one miscarriage with adjuvant nivolumab.
• Literature review of 21 pregnancies: 85.7% live births, ~50% preterm delivery.
• Other outcomes included miscarriage, fetal growth restriction, preeclampsia, and rare neonatal immune effects.

Conclusions:

• Pregnancy outcomes following ICI exposure are variable, with potential for increased adverse events.
• Causality is difficult to establish due to limited data quality and quantity.
• Emphasizes the need for effective contraception and multidisciplinary counseling for patients on ICIs.