Pregnancy Outcomes After in Utero Exposure to Immune Checkpoint Inhibitors

Sep 23, 2026

Immune checkpoint inhibitors (ICIs) have changed cancer care for reproductive-age patients, yet pregnancy outcomes after in utero exposure remain incompletely defined. Two maternal and fetal case experiences are presented alongside a narrative literature review. A retrospective MD Anderson chart review (1 Jan 2015–31 Dec 2024) identified ICI-exposed pregnancies, and PubMed was searched for reported cases. Live birth was common, but miscarriage, preterm delivery, fetal growth restriction, preeclampsia, and rare neonatal immune effects were noted, with causality uncertain. Findings emphasize contraception and multidisciplinary counseling.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages12

Reading Time30 min

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Case Report Pregnancy Outcomes After in Utero Exposure to Immune Checkpoint Inhibitors Morgan Bou Zerdan 1, *, Bruna Kfoury 2, Eliane Aoun 1, Sarah Diane Hmaidan 3, Roni Nitecki Wilke 1, Jeffrey A. How 1, Terri L. Woodard 1, Pamela T. Soliman 1 and Laurie J. McKenzie 1 Received: 5 March 2026 Revised: 25 May 2026 Accepted: 25 May 2026 Published: 28 May 2026 Copyright: © 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. 1 Department of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; [psoliman@mdanderson.org](psoliman@mdanderson.org) (P.T.S.); [ljmckenzie@mdanderson.org](ljmckenzie@mdanderson.org) (L.J.M.) 2 School of Pharmacy, Lebanese American University, Beirut P.O. Box 13-5053, Lebanon; [bruna.kfoury@lau.edu](bruna.kfoury@lau.edu) 3 Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030, USA; [sarah.hmaidan@bcm.edu](sarah.hmaidan@bcm.edu) * [Correspondence: mjb25@mail.aub.edu](Correspondence: mjb25@mail.aub.edu) Simple Summary Immunotherapy has improved cancer treatment outcomes, including for younger patients who may become pregnant during therapy. However, its safety during pregnancy remains unclear. In this study, we describe two patients who were exposed to immunotherapy during pregnancy and review previously reported cases. Most pregnancies resulted in healthy live births, but there was a notable risk of complications such as miscarriage, preterm delivery, and impaired fetal growth. Rare effects on newborns were also reported. These findings highlight the importance of avoiding pregnancy during treatment and ensuring careful counseling and monitoring when exposure occurs. More research is needed to better understand the risks and guide clinical decision-making. Abstract Importance: Immune checkpoint inhibitors (ICIs) have transformed the management of cancers affecting reproductive-age patients, yet their impact on pregnancy outcomes remains incompletely understood. We describe two cases of maternal and fetal outcomes associated with ICI exposure during pregnancy and present a comprehensive literature review. Methods: A retrospective chart review was conducted at MD Anderson Cancer Center (1 January 2015 to 31 December 2024) to identify patients exposed to ICIs during pregnancy. Clinical data including cancer type, treatment timing, pregnancy course, and maternal and neonatal outcomes were collected. A narrative literature review was also performed using PubMed to identify reported cases of ICI exposure during pregnancy. Observations: Two patients were identified at our institution, both treated with ICIs for advanced melanoma. One patient received pembrolizumab during early pregnancy, with the final dose administered five days after conception, and subsequently gave birth to a healthy term infant without complications. The second patient conceived while receiving adjuvant nivolumab and experienced a miscarriage at 13 weeks of gestation. Neither patient experienced immune-related toxicity during pregnancy, and both remained without evidence of disease at follow-up. The literature review identified 21 reported pregnancies with ICI exposure and variable outcomes. Most resulted in live births (85.7%), though preterm delivery occurred in approximately 50% of cases, often due to maternal or fetal indications. Additional reported outcomes included miscarriage, neonatal death, fetal growth restriction, preeclampsia, and rare immune-related neonatal effects. Congenital anomalies were reported in a small number of cases. Conclusions and Relevance: These findings suggest that, while many pregnancies exposed to ICIs result in live births, there may be an increased risk of adverse maternal and fetal outcomes. However, causality cannot be established due to

FAQs

What gap in knowledge does the study address about ICIs and pregnancy?

The study addresses that safety data on ICIs during pregnancy remains extremely limited and pregnancy outcomes are not well understood.

How were patients and literature cases identified in this report?

Patients were identified using a retrospective chart review at MD Anderson (1 Jan 2015–31 Dec 2024), and a narrative literature review was conducted using PubMed to find previously reported ICI-exposed pregnancies.

What kinds of pregnancy and newborn outcomes were observed?

Most pregnancies resulted in live births, but there were notable risks including miscarriage, preterm delivery (often with maternal or fetal indications), fetal growth restriction, preeclampsia, neonatal death in some cases, and rare immune-related neonatal effects.

Sep 23, 2026

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