This is such a challenging issue. We had a patient on adjuvant ipi who developed hypophysitis. She has been off treatment for almost a year, and she would now like to conceive. This is definitely unchartered territory for us, her OB and her Reproductive Endocrinologist. Beyond the hypophysitis, we know that the immune system plays a pivotal role in pregnancy and that there are checkpoints involved (PD-1/PDL-1 being one of them) to prevent the mom’s immune system from attacking the fetus. If a patient is having a durable response to immunotherapy, is the mom’s immune system, in that case, going to be too upregulated to sustain a pregnancy?…….There are certainly lots of unknowns in this realm.