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Biol Neonate 1990;58:54-56
Separation of the Umbilical Cord - Histological Findings A.M. Oudesluys-Murphy a, J.C. den Hollander^ a Department of Paediatrics, Zuiderziekenhuis, and '’Department of Pathology, Erasmus University, Rotterdam, The Netherlands
Key Words. Umbilical cord • Umbilical cord separation • Polymorphonuclear leucocyte
Introduction The umbilical cord is the lifeline of the foetus during intra-uterine life. At birth it is clamped and severed. The remaining cord stump separates within days, leaving the um bilicus as a neat dimple in the abdominal wall. During the rest of life the cord (and its separation) is forgotten. However, interest has become focused on the process of cord separation, since in 1979 Hayward et al. [1] reported an association between delayed separation of the umbilical cord, widespread infections and defective neutrophil mobility. In subsequent studies a genetically determined deficiency of leuco cyte adherence glycoproteins has been found to be the underlying leucocyte disorder [2].
The influences of perinatal factors on the time of umbilical cord separation have also been studied [3, 4]. It has been suggested that drying, infarction, bacterial contamination and granulocyte influx may play roles in the process of separation [5], Some suppose that leucocytes infiltrate and digest the cord [4], and yet others report that the umbilical cord regresses because of a physiological imbal ance between collagénases and inhibitors [ 6], In spite of this interest we could find no description of the process of cord separation in the literature nor of the exact histological findings during separation of the umbilical cord. For this reason we decided to perform a histological study of the umbilical area in a group of infants who died within the first 7
Downloaded by: King's College London 137.73.144.138 - 5/17/2018 9:43:24 PM
Abstract. Even though the separation of the umbilical cord receives a great deal of inter est, the process of cord separation has not been reported in the literature. A histological study of the umbilical area was carried out on 25 neonates who died within 7 days of birth (mean age at death 3 days). The umbilical cord itself became dried and mummified. Polymorpho nuclear leucocytes infiltrated the areas between the mummifying cord stump and the vital tissues of the abdominal wall, forming a demarcation zone. No other leucocytes were present, and no bacteria were seen in any of the preparations studied.
Histology of Umbilical Cord Separation
55
Fig. 1. Schematic representation of the junction between the umbili cal cord and the epidermis at the time of cord separation.
days of birth, that is at an age when the pro cess of cord separation is usually occurring or has just been completed [3],
Materials and Methods Material was studied from 25 neonates who died shortly after birth. The mean age at death was 3 days (range 2 h to 7 days; SD 2.2 days). The group included 9 females and 16 males. The mean gestational age of the neonates was 33 weeks (range 27-43 weeks; SD 5.3 weeks). The mean birth weight was 1,950 g (range 630-4,190 g; SD 1,080 g). Autopsy was performed within 72 h of death. For this study transverse blocks of tissue were removed 1 cm cranially and 1 cm caudally from the centre of the umbilicus, and a longitudinal section was taken inbetween these two blocks (fig. 1). The tissue was fixed in 10% buffered formalin solution, and 10 pm thick sections were stained with hematoxylin and azophloxin. The preparations were reviewed microscopically by both authors.
The transition from epidermis to the amniotic epithelial covering of the cord was vis ible in all the sections except in those cases
Fig. 2. Photograph of the area delimited by the square in figure 1, showing the junction between the amniotic epithelium covering of the cord and the epi dermis, with infiltration of PMNs. X 120.
Downloaded by: King's College London 137.73.144.138 - 5/17/2018 9:43:24 PM
Results
Oudesluys-Murphy/den Hollander
56
Discussion The separation of the umbilical cord is one of those physiological events which is so taken for granted that the process of separa tion itself has not been the subject of wide study. From our findings we conclude that the separation of the umbilical cord involves mummifying of the stump and infiltration of the area of separation with PMNs. The zone of demarcation is located superficially in the plane of the epidermis.
The extent of development of the demar cation zone varied among the preparations studied. It would be interesting to investi gate whether a relationship exists between factors known to influence the time of cord separation, e.g. perinatal events [3, 4], and the histological findings at the time of cord separation.
Acknowledgement We wish to thank Prof. P J. Sauer for his help.
References 1 Hayward, A.R.; Leonard. J.; Wood, C.B.S.; Har vey, Greenwood, M.C.; Soothill, J.F.: De layed separation of the umbilical cord, widespread infections and defective neutrophil mobility. Lan cet i: 1099-1101 (1979). 2 Berkinshaw, C.J.; Weemaes, C.M.R.; Roos, D.; Tetteroo, P.A.T.; Weening, R.S.: Congenital defi ciency of leukocyte adherence glycoproteins: a fa milial defect. Neth. J. Med. 31: 158-170 (1987). 3 Oudesluys-Murphy, A.M.; Eilers, G.A.M.; de Groot, C.J.: The time of separation of the umbili cal cord. Eur. J. Pediat. 146: 387-389 (1987). 4 Novack, A.H.; Mueller. B.: Ochs, H.: Umbilical cord separation in the normal newborn. Am. J. Dis. Child. 142: 220-223 (1988). 5 Wilson, C.B.; Ochs, H.D.; Almquist, J.; Dassel, S.; Mauseth. R.: Ochs, U.H.: When is umbilical cord separation delayed? J. Pediat. 107: 292-294 (1985). 6 Lubec. G.: Collagenase activity in the human um bilical cord. Padiat. Padol. 12: 258-262 (1977).
A.M. Oudesluys-Murphy Department of Paediatrics Zuiderziekenhuis Groene Hillcdijk 315 NL-3075 EA Rotterdam (The Netherlands)
Downloaded by: King's College London 137.73.144.138 - 5/17/2018 9:43:24 PM
where the cord had recently separated. In the latter cases the transition is formed by the epidermis and a layer of fibrinous material on the umbilical bed. Where the cord stump was still attached, it appeared as a dried shrivelled mummified string. No bacteria and no leucocytes were seen in the cord stump. However, infiltrating polymorphonuclear leucocytes (PMNs) were seen in all the prep arations (irrespective of whether the umbili cal cord was still attached or already sepa rated) at the junction of the umbilicus and the epidermis, progressing from the edge to wards the center (fig. 1,2). In some cases this was limited to the edges, and in others it had reached the centre and formed a continuous band. This band of PMNs was narrow and vaguely defined in some cases, but in others it was wide and clearly visible. This band formed a demarcation zone between the mummified cord stump and the umbilical area from which the cord was in the process of separating or had just separated. The only cells seen in this demarcation zone were PMNs. No mononuclear cells or macro phages were seen in this area, and there were no bacteria present.
Biol Neonate 1990;58:54-56
Separation of the Umbilical Cord - Histological Findings A.M. Oudesluys-Murphy a, J.C. den Hollander^ a Department of Paediatrics, Zuiderziekenhuis, and '’Department of Pathology, Erasmus University, Rotterdam, The Netherlands
Key Words. Umbilical cord • Umbilical cord separation • Polymorphonuclear leucocyte
Introduction The umbilical cord is the lifeline of the foetus during intra-uterine life. At birth it is clamped and severed. The remaining cord stump separates within days, leaving the um bilicus as a neat dimple in the abdominal wall. During the rest of life the cord (and its separation) is forgotten. However, interest has become focused on the process of cord separation, since in 1979 Hayward et al. [1] reported an association between delayed separation of the umbilical cord, widespread infections and defective neutrophil mobility. In subsequent studies a genetically determined deficiency of leuco cyte adherence glycoproteins has been found to be the underlying leucocyte disorder [2].
The influences of perinatal factors on the time of umbilical cord separation have also been studied [3, 4]. It has been suggested that drying, infarction, bacterial contamination and granulocyte influx may play roles in the process of separation [5], Some suppose that leucocytes infiltrate and digest the cord [4], and yet others report that the umbilical cord regresses because of a physiological imbal ance between collagénases and inhibitors [ 6], In spite of this interest we could find no description of the process of cord separation in the literature nor of the exact histological findings during separation of the umbilical cord. For this reason we decided to perform a histological study of the umbilical area in a group of infants who died within the first 7
Downloaded by: King's College London 137.73.144.138 - 5/17/2018 9:43:24 PM
Abstract. Even though the separation of the umbilical cord receives a great deal of inter est, the process of cord separation has not been reported in the literature. A histological study of the umbilical area was carried out on 25 neonates who died within 7 days of birth (mean age at death 3 days). The umbilical cord itself became dried and mummified. Polymorpho nuclear leucocytes infiltrated the areas between the mummifying cord stump and the vital tissues of the abdominal wall, forming a demarcation zone. No other leucocytes were present, and no bacteria were seen in any of the preparations studied.
Histology of Umbilical Cord Separation
55
Fig. 1. Schematic representation of the junction between the umbili cal cord and the epidermis at the time of cord separation.
days of birth, that is at an age when the pro cess of cord separation is usually occurring or has just been completed [3],
Materials and Methods Material was studied from 25 neonates who died shortly after birth. The mean age at death was 3 days (range 2 h to 7 days; SD 2.2 days). The group included 9 females and 16 males. The mean gestational age of the neonates was 33 weeks (range 27-43 weeks; SD 5.3 weeks). The mean birth weight was 1,950 g (range 630-4,190 g; SD 1,080 g). Autopsy was performed within 72 h of death. For this study transverse blocks of tissue were removed 1 cm cranially and 1 cm caudally from the centre of the umbilicus, and a longitudinal section was taken inbetween these two blocks (fig. 1). The tissue was fixed in 10% buffered formalin solution, and 10 pm thick sections were stained with hematoxylin and azophloxin. The preparations were reviewed microscopically by both authors.
The transition from epidermis to the amniotic epithelial covering of the cord was vis ible in all the sections except in those cases
Fig. 2. Photograph of the area delimited by the square in figure 1, showing the junction between the amniotic epithelium covering of the cord and the epi dermis, with infiltration of PMNs. X 120.
Downloaded by: King's College London 137.73.144.138 - 5/17/2018 9:43:24 PM
Results
Oudesluys-Murphy/den Hollander
56
Discussion The separation of the umbilical cord is one of those physiological events which is so taken for granted that the process of separa tion itself has not been the subject of wide study. From our findings we conclude that the separation of the umbilical cord involves mummifying of the stump and infiltration of the area of separation with PMNs. The zone of demarcation is located superficially in the plane of the epidermis.
The extent of development of the demar cation zone varied among the preparations studied. It would be interesting to investi gate whether a relationship exists between factors known to influence the time of cord separation, e.g. perinatal events [3, 4], and the histological findings at the time of cord separation.
Acknowledgement We wish to thank Prof. P J. Sauer for his help.
References 1 Hayward, A.R.; Leonard. J.; Wood, C.B.S.; Har vey, Greenwood, M.C.; Soothill, J.F.: De layed separation of the umbilical cord, widespread infections and defective neutrophil mobility. Lan cet i: 1099-1101 (1979). 2 Berkinshaw, C.J.; Weemaes, C.M.R.; Roos, D.; Tetteroo, P.A.T.; Weening, R.S.: Congenital defi ciency of leukocyte adherence glycoproteins: a fa milial defect. Neth. J. Med. 31: 158-170 (1987). 3 Oudesluys-Murphy, A.M.; Eilers, G.A.M.; de Groot, C.J.: The time of separation of the umbili cal cord. Eur. J. Pediat. 146: 387-389 (1987). 4 Novack, A.H.; Mueller. B.: Ochs, H.: Umbilical cord separation in the normal newborn. Am. J. Dis. Child. 142: 220-223 (1988). 5 Wilson, C.B.; Ochs, H.D.; Almquist, J.; Dassel, S.; Mauseth. R.: Ochs, U.H.: When is umbilical cord separation delayed? J. Pediat. 107: 292-294 (1985). 6 Lubec. G.: Collagenase activity in the human um bilical cord. Padiat. Padol. 12: 258-262 (1977).
A.M. Oudesluys-Murphy Department of Paediatrics Zuiderziekenhuis Groene Hillcdijk 315 NL-3075 EA Rotterdam (The Netherlands)
Downloaded by: King's College London 137.73.144.138 - 5/17/2018 9:43:24 PM
where the cord had recently separated. In the latter cases the transition is formed by the epidermis and a layer of fibrinous material on the umbilical bed. Where the cord stump was still attached, it appeared as a dried shrivelled mummified string. No bacteria and no leucocytes were seen in the cord stump. However, infiltrating polymorphonuclear leucocytes (PMNs) were seen in all the prep arations (irrespective of whether the umbili cal cord was still attached or already sepa rated) at the junction of the umbilicus and the epidermis, progressing from the edge to wards the center (fig. 1,2). In some cases this was limited to the edges, and in others it had reached the centre and formed a continuous band. This band of PMNs was narrow and vaguely defined in some cases, but in others it was wide and clearly visible. This band formed a demarcation zone between the mummified cord stump and the umbilical area from which the cord was in the process of separating or had just separated. The only cells seen in this demarcation zone were PMNs. No mononuclear cells or macro phages were seen in this area, and there were no bacteria present.
