The First 6 Years' Experiences of a National Centralized Offspring Surveillance Setting for Dutch Children Prenatally Exposed to Maternal Cancer to Inform Future International Practice: Protocol for a Demographic Review of Referred Families and Key Lessons Learned.

backgroundCancer during pregnancy is a rare and significant life-changing event affecting approximately 1 in 1000-2000 pregnancies. With increasing maternal age and broader application of prenatal screening programs such as the Dutch Non-Invasive Prenatal Testing, incidental detection of maternal cancer is becoming more frequent. Advancements in safe treatment options during pregnancy, supported by the International Network on Cancer Infertility and Pregnancy (INCIP), have led to fewer pregnancy terminations. Consequently, more children are exposed to chemotherapy and other cancer treatments in utero. While short-term safety has been demonstrated for many oncological agents, long-term side effects including physical, neuromotor, neurocognitive, and psychosocial impacts on offspring and their families after delivery are still being assessed. Standard settings for surveillance and care of offspring and their families have, however, never been described.

objectiveGiven the importance of expertise in assessing the long-term outcomes of children, the Netherlands established the national centralized Cancer in Pregnancy (CIP) offspring outpatient clinic in 2018, which functions as a standard-of-care surveillance clinic and contributes data to the INCIP registry. Here we provide a demographic overview of referred families and to share (logistic) experiences with the national, centralized, multidisciplinary, and standardized long-term surveillance program for all Dutch children with in utero exposure to maternal cancer and its treatment.

methodsThe CIP offspring outpatient clinic is located at the Princess Máxima Center for Pediatric Oncology and provides surveillance from infancy until 18 years of age. The, relatively small dedicated team, comprising pediatric oncologists, physiotherapists, and a psychological expert, offers a 1-day, multidisciplinary assessment, including physical examinations, neuromotor tests, cardiac monitoring (for anthracycline exposure), renal and auditory screening (for platinum agents), neurocognitive testing, and psychosocial evaluation. Surveillance is aligned with international INCIP guidelines.

resultsFrom May 2018 to 2024, a total of 226 children (from 221 mothers) have been referred to the CIP offspring outpatient clinic, with 465 follow-up visits completed. The most common maternal cancer types were breast, gynecological, and hematological malignancies. Most women (58%) received chemotherapy during pregnancy; 11% of them had surgery only, 3% underwent radiotherapy, 3% underwent immunotherapy, 16% received a combination of treatment modalities, and 8% did not undergo treatment during pregnancy. Anthracyclines were the most commonly used agents. Median gestational age at delivery was 37.3 weeks. Fourteen percent of the mothers died shortly after delivery, underscoring the emotional and logistical challenges for families.

conclusionsThe CIP offspring outpatient clinic provides a unique, structured approach to long-term surveillance for in utero-exposed children, which enables early detection of potential late effects and provides comprehensive family support. By sharing knowledge and experiences from the unique setting of this national centralized CIP offspring outpatient clinic, this initiative may inspire other countries in developing similar translational facilities to support affected families and improve care worldwide. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/71612.