The Role of Cytokines in Early Pregnancy: Fertilization, Implantation, and Maintenance

• Published in: Current obstetrics and gynecology reports 2024-06, Vol.13 (2), p.59-65
• Main Authors: Crants, Shelby, Yin, Sophia, Andrusier, Miriam A., Reddy, Rajesh, Ginsburg, Elizabeth S.
• Format: Article
• Language: English
• Subjects: Maternal and Child Health; Medicine; Medicine & Public Health; Obstetrics/Perinatology/Midwifery; Oncology; Review; Topical Collection on Reproductive Endocrinology and Infertility (REI)
• ISSN: 2161-3303; 2161-3303
• DOI: 10.1007/s13669-024-00380-3

Purpose of the Review Early pregnancy presents a unique immunological phenomenon, wherein the maternal immune system must tolerate the allogeneic fetus. The complex immunoregulation required to orchestrate this balance is believed to be mediated by cytokine profiles specific to pregnancy. This article examines the responsible cytokines and their roles, and how their interplay predicts continued pregnancy or spontaneous miscarriage. It also explores the conflicting theories on their contribution to pregnancy outcomes. Recent Findings Recent studies have furthered the hypothesis that the maternal immune response is responsible for outcomes across the pregnancy spectrum, from early pregnancy loss to preeclampsia. They dispute, however, previous notions that successful pregnancy is exclusively a phenomenon of immune suppression. Reproductive failure cannot easily be explained by simple imbalances of the Th1- and Th2-associated cytokines. Furthermore, therapeutics have been suggested for recurrent pregnancy failure based on the importance of cytokines in early pregnancy. Summary While disruptions in cytokine balance have been associated with poor outcomes, recent research has challenged the paradigm that cytokine levels alone are determinative. Instead, they advance a revised model of cytokines as mediators of a delicate sequence of pro- and anti-inflammatory events that facilitate pregnancy continuation.