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Updated: Aug 15, 2026
Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats
Published on: November 20, 2015
Effects of intra-amniotic meconium exposure on the fetal rat: development of a pathogenic model
S C Blackwell1, M Hallak, J W Hotra
1Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Wayne State University/Hutzel Hospital, Detroit, Mich., USA. mfmboy@aol.com
Objective:
To develop an in vivo animal model for the study of the effects of intrauterine meconium exposure on the fetus.
Methods:
Timed pregnant Long-Evans rats were purchased on gestational day (GD) 12 and allowed to acclimate for at least 48 h prior to surgery. Laparotomy was performed and both uterine horns were exteriorized through the abdominal incision. A 26-gauge needle was used to inject either 0.1-cm(3) sterile normal saline or a 20% meconium suspension into each individual gestational sac. The uterus was returned to the abdomen and the incision was closed. On GD 21 (term = 21 days) a cesarean section was completed and the number and viability of fetuses in each horn were recorded.
Results:
A total of 14 animals were involved in this pilot study. One rat underwent sham surgery with only intra-amniotic saline injection and 13/15 fetuses survived to term. Two animals that underwent surgery on day 18 expired < 24 h postinjection. Eleven maternal animals were injected on GD 20 and underwent cesarean delivery at term; survival rates for saline-injected animals were 71.2% compared to 66.2% for meconium-exposed fetuses.
Conclusion:
We have established an in vivo animal model that allows for the examination of the effects of prolonged intrauterine meconium exposure on the fetus.
