Related Experiment Video

Updated: Jun 25, 2026

Transuterine Fetal Tracheal Occlusion Model in Mice
06:31

Transuterine Fetal Tracheal Occlusion Model in Mice

Published on: February 5, 2021

Congenital perineal hernia in a fetus with trisomy 18

Thora S Steffensen1, John M Opitz, Enid Gilbert-Barness

  • 1Department of Pathology, University of South Florida and Tampa General Hospital, Tampa, Florida 33606, USA.

Fetal and Pediatric Pathology
|February 26, 2009
PubMed

Insights

This study reports the first known case of a prenatal perineal hernia in a fetus with trisomy 18. This rare condition involved bowel prolapse and occurred during gestation.

Area of Science:

  • Medical genetics
  • Fetal medicine
  • Surgical pathology

Background:

  • Perineal hernias are exceptionally rare congenital abnormalities, predominantly documented in adult populations.
  • Pediatric cases of perineal hernia are scarce, with only seven instances previously reported in literature.
  • Prenatal diagnosis and association with specific genetic syndromes remain largely undocumented.

Observation:

  • A female fetus, evaluated at 18 weeks of gestation due to confirmed trisomy 18, presented with a significant perineal hernia.
  • The anomaly was characterized by a defect in the perineal skin, allowing for the prolapse of multiple intestinal loops.
  • This finding was observed alongside other typical phenotypic manifestations associated with trisomy 18.

Findings:

  • The presented case represents the first documented instance of antenatal perineal hernia.
  • This is also the inaugural report linking perineal hernia to trisomy 18.
  • The complex presentation highlights potential associations between genetic abnormalities and rare structural defects.

Implications:

  • This case expands the spectrum of known fetal anomalies associated with trisomy 18.
  • It underscores the importance of detailed prenatal imaging for identifying rare congenital defects.
  • Further research may elucidate the embryological mechanisms connecting trisomy 18 and perineal hernias.

More Related Videos

Continuous Telemetric In Utero Tracheal Pressure Measurements in Fetal Lambs05:40

Continuous Telemetric In Utero Tracheal Pressure Measurements in Fetal Lambs

Published on: December 22, 2023

Related Concept Videos

Meiosis I01:49

Meiosis I

Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by a...
Neurulation01:30

Neurulation

Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the anterior...
Teratogenicity01:07

Teratogenicity

The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and the drug producing this effect is known as a teratogen. Teratogenic effects include stillbirth, miscarriage, intrauterine growth restriction, and neurocognitive delay. A teratogen may affect the embryo at different stages of development, which is important in determining the type and extent of the damage. During blastocyst formation, the early...
Muscles of the Pelvic Floor and Perineum01:26

Muscles of the Pelvic Floor and Perineum

The muscles of the pelvic floor and perineum are crucial for supporting the pelvic organs, controlling continence, and aiding in sexual function, childbirth, and core stability. They are typically divided into the superficial perineal layer and the deep pelvic floor layer.
Perineal Layer
The perineum is a diamond-shaped area below the pelvic diaphragm, divided into an anterior urogenital triangle that contains the external genitals and a posterior anal triangle housing the anus. The urogenital...
Nondisjunction01:21

Nondisjunction

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers.  Nondisjunction is common during anaphase I or anaphase II of meiosis.  Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold sister...
Nondisjunction01:29

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.