Circumferential Abdominal Skin DefectPossibly Due to Umbilical Cord EncirclementA.E. LIN,1,2* D.R. GENEST,3 AND D.L. BROWN4

1Department of Newborn Medicine, Brigham and Women’s Hospital, Boston, Massachusetts 021152Genetics and Teratology Unit, Pediatric Service, Massachusetts General Hospital, Boston, Massachusetts 021143Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts 021154Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115

ABSTRACT We report on a newborn blackmale twin with a distinctive circumferential abdominalskin defect who was identified through the ActiveMalformation Surveillance Program at the Brigham andWomen’s Hospital. There were no other malformations,and amniotic disruption was not present. Although itcannot be proven, we believe that this skin defect mayhave been caused by in utero encirclement of theabdomen by an umbilical cord. Teratology 60:258–259, 1999. r 1999 Wiley-Liss, Inc.

Absent skin in newborns is usually referred to as‘‘aplasia cutis congenita’’ (Der Kaloustian, ’93). Etiologicheterogeneity has been well-demonstrated. Although adisruptive process such as amniotic band strands andadhesions has been proposed as a possible nongeneticmechanism, it has not been proven (Der Kaloustian, ’93).We report on a newborn with a distinctive circumferentialabdominal skin defect. We believe this represents a uniqueexample of another type of developmental disruption, i.e.,intrauterine mechanical erosion or compression.

CASE REPORT

This boy (and his co-twin) were born to a G6, electedtermination 5, 34-year-old African-American woman.She was a long-term tobacco user who smoked at leastone pack per day during this pregnancy. The medicalrecord reported heroin and cocaine use until 1 yearprior to conception. During pregnancy the motherdenied drug use. A urine toxicology screen was refusedat the time of delivery. The family history for themother and 35-year-old father were not contributory.The mother stated that the maternal serum alpha-fetoprotein obtained elsewhere was elevated, prompt-ing the ultrasonographic examination.

The targeted ultrasonographic examination at18 weeks showed twin gestation. Sonographic imageswere compromised by maternal obesity. As on the firstsonogram at 18 weeks, subsequent ultrasonographicexaminations at 30, 34, and 35 weeks showed a thinlinear echo in the amniotic cavity. Based on this,placentation was thought to be diamniotic monochori-onic. When reviewed retrospectively, there was noevidence of the umbilical cords encircling either fetus.

At 34 weeks of pregnancy, the twins were deliveredby cesarean section because of a poorly reactive non-stress test. The pediatrician present at delivery ob-served an unusual skin defect encircling the lowerabdomen. He noted a poorly defined ‘‘strand’’ of tissue,somewhat adherent to skin on the infant’s back, whichwas not sent for pathologic examination. Because thistissue was thought to be an amniotic strand, thediagnosis of amniotic band disruption sequence wasoffered. However, pathologic examination showed amonochorionic, monoamniotic placenta with no gross orhistologic evidence of amniotic disruption. The umbili-cal cord length was 44 cm (37 cm in the co-twin). Eachhad three vessels.

Physical examination of the newborn showed a well-nourished, healthy-appearing, nondysmorphic blackmale who weighed 1,960 g (10th centile for 36 weeks).There was a completely circumferential, slightly infra-umbilical defect of the skin and subcutaneous tissue,with sharp margins and mild indentation (Fig. 1A,B).The area was moist without bleeding, and dressingswere applied. No strands, other constrictions, or reduc-tions were detected. Reexamination at age 14 monthsshowed a completely healed, slightly constricted, andmildly hyperpigmented scar (Fig. 2A,B). There was theappearance of a rounded groove. The patient and hisco-twin were otherwise healthy.

DISCUSSION

Several possible causes of this unusual skin defectcan be excluded. Because the amniotic sac was intact,and amniotic fragments were not present, we think ithighly unlikely that the amniotic band sequence was

Grant sponsor: Massachusetts Department of Public Health (CDC).

This paper was reviewed by the Massachusetts Department of PublicHealth, and approved for publication. Approval does not signify thatthe contents necessarily reflect the views and policies of the Massachu-setts Department of Public Health, its Commissioner, or any of itsagents or governing authorities.

*Correspondence to:Angela E. Lin, M.D., Teratology Program, Brighamand Women’s Hospital, Old PBBH B5-501, 75 Francis St., Boston, MA02115. E-mail: lin.angela@mgh.harvard.edu

Received 5 April 1999; Accepted 7 June 1999

TERATOLOGY 60:258–259 (1999)

r 1999 WILEY-LISS, INC.

present (Gorlin et al., ’90). The linear skin defectcompletely encircled the abdomen, making it also un-likely that this was a primary development error, sinceaplasia congenita cutis is usually randomly located,linear, and unrelated to a dermatome (Der Kaloustian, ’93).There was no microcephaly or cicatricial limb defects tosuggest fetal varicella syndrome (Jones et al., ’94).

Although we do not have prenatal ultrasonographicconfirmation, we believe that this skin defect wascaused by an umbilical cord which encircled and com-pressed the skin on the abdomen (Blackburn andCooley, ’93). Prolonged contact with pressure causednecrosis of the skin. There is no evidence that thecompressing cord belonged to either the twin or co-twin.This type of umbilical cord encirclement can be viewedas a ‘‘surface encounter’’ (Group II, B, amnion-to-skin,band type in Table 1, Blackburn et al., ’97). These loops ofcord may cause significant deformation of fetal parts, butthe location and erosive nature of the skin defect in thispatient is unique. In addition to the thickened scar noted at14 months, there was mild indentation, supporting thenotion that the umbilical cord loop compressed tissues.

This twin and his co-twin were contained in a singleamniotic sac, a finding observed in other cases ofumbilical cord accidents (Blackburn and Cooley, ’93).However, the twins had normal amniotic fluid volumeand relatively short cords (44 and 37 cm), possibly due

to fetal crowding. In contrast, Benirschke (’94) sug-gested that 45 cm was the minimum cord length toproduce a cord loop, a comment made in the context of adiscussion of nuchal loops. Pathologic examination ofplacentas has found no evidence of a twin or triplet demiseassociated with a shriveled cord acting as a constriction‘‘band.’’ The literature documents a few other cases ofumbilical cord deformations, but none involving the abdo-men in this distribution (Blackburn and Cooley, ’93).

A puzzling finding was the ultrasonographic observa-tion of a thin linear echo in the amniotic cavity. Onecould speculate that this could have been a diamnioticpregnancy in which the dividing membranes ruptured,capturing one baby in the connecting hole. This alterna-tive scenario implies that an amniotic membrane ratherthan the umbilical cord caused the abdominal indenta-tion. Against this mechanism was the absence of anyremnant of such a dividing membrane in the placentalspecimen. The moist, eroded skin suggested a recentorigin of the compression (regardless of the actualagent), and a dividing membrane would likely bepresent. In the setting of an overweight mother, an-other interpretation we think unlikely is that a subopti-mal ultrasonographic scan mistakenly identified theedge of the umbilical cord for a membrane.

In this patient, what remains unanswered is thetiming and duration of the postulated encirclement.The absence of in utero healing suggests that it was athird-trimester event.

ACKNOWLEDGMENTS

The authors are deeply grateful to Dr. Will Blackburnof the Greenwood Genetic Center, and Dr. Kurt Benir-schke of the University of San Diego, for reviewing thecase and providing invaluable insights. They thank Dr.Eric Eichenwald for allowing us to examine this baby,and Dr. Louise Wilkins-Haug for clinical assistance.

This study was supported in part by the NationalCenter for Environmental Health, Centers for DiseaseControl and Prevention through a grant to the Massa-chusetts Center for Birth Defects Research and Preven-tion, Massachusetts Department of Public Health.

LITERATURE CITEDBenirschke K. 1994. Obstetrically important lesions of the umbilical

cord. J Reprod Med 39:262–272.Blackburn W, Cooley NR. 1993. The umbilical cord. Umbilical cord

loops (‘‘encirclements’’). In: Stevenson RE, Hall JG, Goodman RM,editors. Human malformations and related anomalies, volume II.New York: Oxford University Press. p 1112–1114.

Blackburn W, Stevenson RE, Cooley NR, Stevens CA, Judson A. 1997.An evaluation and classification of the lesions attending abnormalsurface encounters within the fetal habitat. Proc Greenwood GenetCenter 16:81–89.

Der Kaloustian VM. 1993. Skin. In: Stevenson RE, Hall JG, GoodmanRM, editors. Human malformations and related anomalies. NewYork: Oxford University Press. p 934–936.

Gorlin RJ, Cohen MM Jr, Levin LS. 1990. Amnion rupture sequence.In: Syndromes of the head and neck, 3rd ed. New York: OxfordUniversity Press. p 11–14.

Jones KL, Johnson KA, Chambers CD. 1994. Offspring of womeninfected with varicella during pregnancy: a prospective study.Teratology 49:29–32.

Fig. 1. View of the patient’s infraumbilical skin defect, traversing thelower abdomen. A: As a newborn. B: Well-healed scar with keloid at 14months.

Fig. 2. View of patient’s back, showing the defect completely encir-cling the torso. A: As a newborn. B: At 14 months.

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