Related Experiment Video
Updated: Jun 27, 2026
08:50
A Murine Model of Fetal Exposure to Maternal Inflammation to Study the Effects of Acute Chorioamnionitis on Newborn Intestinal Development
Published on: June 24, 2020
Timing of fetal meconium absorption by amnionic macrophages
Edmund F Funai1, Anna T Labowsky, Caroline E Drewes
1Section of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut, USA.
American Journal of Perinatology
|November 26, 2008
Summary
This study reveals that significant meconium uptake by placental membranes and macrophages occurs after 24-48 hours, challenging previous findings on meconium staining timelines.
Area of Science:
- Perinatal Medicine
- Immunology
- Histology
Background:
- Meconium exposure in amniotic fluid is a concern during pregnancy.
- The timing of meconium staining and macrophage involvement in placental membranes is not fully understood.
Purpose of the Study:
- To determine the time course of meconium staining and uptake by amnionic macrophages in placental membranes.
- To investigate the interval between fetal defecation and placental membrane changes.
Main Methods:
- An in vitro model using placental membrane sections exposed to meconium and amniotic fluid.
- Microscopic analysis of membranes at various time points (1-48 hours) for meconium presence and macrophage activity.
Main Results:
- Minimal meconium-laden macrophages were observed before 12 hours.
- Significant increases in meconium-laden macrophages and staining intensity were noted at 24 and 48 hours.
Conclusions:
- In vitro findings suggest a delayed uptake of meconium by placental membranes and macrophages, occurring after 24 hours.
- This contradicts earlier reports, indicating a longer interval for meconium incorporation into placental tissues.
Related Concept Videos
01:22Development of Immunocompetence
The initiation of cell-mediated immunity can be observed as early as the third month of fetal growth, with active antibody-mediated immunity following approximately one month later.
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
01:15Transcytosis of IgG
Transcytosis is the process in which molecules are internalized by endocytosis, transported across the cell, and released through exocytosis from the opposite end of the cell. Molecules such as insulin, immunoglobulins, and certain nutrients are transferred through the recycling endosomes by recycling and transcytosis.
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...
01:28Development of the Oral Microbiota
The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
01:30Development of Human Microbiota
The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...