Quantification of the Trophoblast: A Systematic Review and Meta-analysis

Mamata Panigrahi, Shweta Solan, Smruti Rekha Mohanty

Abstract

Background and Aim: Trophoblasts constitute the outer layer of blastocysts. Trophoblasts provide nutrition to the embryo, and eventually, develop into a large part of the placenta. These cells that are formed in the first phase of pregnancy are the first to evolve from the fertilized embryo. There are many methods of quantifying trophoblasts; however, the results of each method vary because of the differences in placental formation.

The aim of this study was to systematically review and meta-analyze the relationship between trophoblast quantification, placental function, and pregnancy outcomes.

Materials and Methods: The article selection for the systematic review and meta-analysis focused on papers published from 2002 to 2022, using the search terms “trophoblast quantification,” “placental weight,” and “birth weight” in PubMed, Scopus, and Google Scholar. Articles were included if they provided relevant data on trophoblast quantification and the placental weight to birth weight ratio. Of the 57 initially identified articles, 17 met the criteria, and 5 were selected for detailed analysis. The selection process adhered to PRISMA guidelines to ensure thorough and transparent reporting.

Results: The classic ectopic pregnancy triad of abdominal pain, vaginal bleeding, and amenorrhea often leads to an increased proliferation rate of trophoblasts, resulting in a higher number of trophoblasts. The current meta-analysis corroborates this fact, as the initial value and the odds ratio match the obtained Z score for this observation. In instances where the trophoblast numbers are high, trophoblast quantification exhibits a notably higher measurement. Additionally, understanding the ratio of placental weight to birth weight is crucial for the provision of tertiary care to pregnant women.

Conclusion: This study highlights the importance of accurate trophoblast quantification and its role in understanding placental development and function. Also, a knowledge of the amniotic fluid and blood volume is essential for deeper understanding of the conditions needed for optimal placental and trophoblast functioning, which will aid accurate assessments and interventions.