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Amniotic bands as a cause of intrauterine fetal death
AMNIOTIC BANDS FETAL DEATH
AS A CAUSE
OF INTRAUTERINE
A Case Report MELVILLE IMMANI.EL (From the Obstetrical Texas)
Department of and Gynecological
Obstetrics Service,
I,. CODY, M.D., HOUSTON, TEXAS, ANII F. UETZMANN, CAPTAIN, USAF (MC:!
and Gynecology, United States
Baylor College oj Medicine, and the Base Hospita!, Ellington Air Force Base,
MNIOTIC bands are not rare in pregnancies ending in ahnrticm in thtl early months. Small threadlike strands have been described connecting the aborted fetus to an otherwise normal-appearing amnion. Instead of t,hreadlike, they may be tent shaped, with the apex attached to the body, head, or ends of the fingers or toes. In early intrauterine esistencc, due to a more right-angular attachment of the appendages to the body, contact with thcx amnion might be expected to occur readily t,o the head and digits.’ Wha.t causes these adhesions can only be conjectured. Amniotic aclhesions and resulting fetal deformities a,re known to occur in ectopic gestations wit.h more frequency than in normal gestations. In the term or near-term, otherwise normal intrauterine gestation, these amniotic bands are extremely rare. When they do occur. such bands, arising from the amnion, may be free at the other end, or attached to t,he fetns or to another area of the amnion. Loops may form around portions of the fetus, including digits or portions of extremities, causing corresponding deformities. These strands may entangle the umbilical cord, causing strangulation of t,he cord and intrauterine death. Fetal death may occur ante partum, intrapartum, or post partum. One reported cast was that of a child born alive at term who died shortly thereafter.2 Duncan2 compiled from the world literature 8 cases of fetal dea.th causccl by amniotic strings and added 2 others, one of his own and one of C(ra~cn ant1 &ddes4 in the addendum to his article. The case herewith report,4 brings the total from the world literature to 11.
A
The patient was a 19.pear-old white girl, gravida i, para 0. who was first seen at Ellington Air Force Base on July 9, 1956. At that time she was approximately 34 weeks pregnant. The last normal menstrual period had been Nov. 13, 1955, and t,he expecter1 date of confinement was Aug. 20, 1956. On the last prenatal visit, July 25, the fetal heartbeat was 140, heard in the left lower quadrant, strong and regular. Laborator,v tests were completely withiu normal limits. The Rh factor was negative and the 1~10011 tapes was A. The patient was admitted on July 30 in active labor. She stated that she had not noticed her baby moving for the past four days an<1 the fetal heartbeat could not be 1102
AMNIOTIC
\‘uhlme Number
71 5
heard
at this
delivered shortly
Pig
l.-Amniotic
Fig. becoming surface.
time.
under thereafter
BANDS A macerated
pudendal without
band
Z.-Section a stringlike The opposite
arises
CAUSING stillborn
block anesthesia difficulty.
from umbilical
both
INTRAUTERINE female with
cord and cord, causing
through the separated structure shows amnion torn surface contains
FETAL
infant
weighing
Trilene,
anI1
placenta and strangulation.
6 pounds the
wraps
was
placenta
itself
1103
DEATH
eventually
was
tightly
amniotic membrane twisting on itself cells occurring as a single layer some scattered chorionic trophoblastic
expressed
around
just covering
cells.
the
before one
110-l The umbilical cord presented a brownish-gray ~liscoloration down to a point 4% inches from its insertion in the placenta, where there was a constriction; on the placental side of this point the cord was normal in appearance (Fig. 1). A strand wrapped on itself in places and in other places appearing as a plain string of tissue was found to be bound tightly around the cord three and one half times. At one end this strand fanned out into what appeared grossly to be amniotic membrane attached to both the placenta and the cord near its placental attachment. From the constriction of the cord, the amniotic band emerged as two strands, each of which fanned out into a paper-thin membrane common to both, but free of any attachment to any other structures. Pathological Examination.-It was the opinion of Wilson G, Brown, the chief pathoi ogist at Hermann Hospital, that the separated membrane (Fig. 2) had as one surface a single layer of clearly identifiable amnion cells with cuboidal, oval, or slightly irregular pale-blue nuclei and indistinct cytoplasmic borders. The opposing surface showed an occasional plump cell with acidophilic cytoplasm an<1 small darkly stained nucleolus apIt was believed that the amnion had split parently representing a remnant of chorion. from the adjacent chorion, carrying with it occasional scattered trophoblastic cells.
Comment Amniotic bands can bc deforming as well as fatal. Traumatic tmbryonic amputations have been recognized and reported on sporadically since the very early 1800’s. There was in all probability knowledge concerning t,hem long before then. J,cnnon3 noted that Watkinson in 1825 gave the first report of an intrauterine amputation, but did not record the presence or absence of bands. The left leg had been completely amputated a little above the ankle. The foot was found in the vagina, rat,her well preserved following the prcmature birth of the infant at seven months’ gestation. Over the years numerous theories have been postulated as to the etiology of amniotic bands, including : (1) inff ammation of the amnion ; (2) abnormal disposition of portions of the amnion ; (3) maldevelopment of the amnion (developmental, instead of traumatic) ; (4) environmental influences ; (5) dietetic influences ; (6) rubella. LcnnonS felt that amniotic bands are not adhesions, but are the result of faults in the developing amnion. We agree with him and believe that at least two factors or mechanisms are involved in the formation of these curious strands. First, an adhesive process takes place between an area of amnion and an area of the fetus, or perhaps another part of the amnion. Over a period of time the amnion is stretched, forming sheets or strings of varying shapes. The etiology of the initial adhesion could be abnormal amnion-chorion attachment to or detachment from adjacent structures: decidua or myometrium in intraInuterine pregnancies or adjacent viscera in extrauterine pregnancies. flammation in these areas may play a role. Second, the integrity of the amnion may be disrupted in such a way that it would peel off, twist on itself, and form a string. This might occur as a result of premature rupture of the membranes. Possibly long finger- or toenails might initiate a tear in sites other than the cervical OS. These cases are
Vdume
Number
71
i
AMNIOTIC
BANDS
ChUSTNG
INTRAUTERTNE
so rare and arc so virtually undiagnosable probably only of academic interest.
FETAL
before delivery
DEXTH
that their
110.5
cause is
References Pathology of the Fetus and the Newborn, Chicago, E. L.: Publishers, Inc., p. 533. 2. Duncan, A. S.: J. Obst. & Gynaec. Brit. Emp. 60: 529, 1953. 3. Lennon, G. G.: J. Obst. & Gynaec. Brit. Emp. 60: 830, 1947. 4. Craven, F. WK., and Gedrles, C. J. M.: Brit. Ued. J. 1: 81, 1953. 1. Potter,
1952,
The
Year
Book
AS A CAUSE
OF INTRAUTERINE
A Case Report MELVILLE IMMANI.EL (From the Obstetrical Texas)
Department of and Gynecological
Obstetrics Service,
I,. CODY, M.D., HOUSTON, TEXAS, ANII F. UETZMANN, CAPTAIN, USAF (MC:!
and Gynecology, United States
Baylor College oj Medicine, and the Base Hospita!, Ellington Air Force Base,
MNIOTIC bands are not rare in pregnancies ending in ahnrticm in thtl early months. Small threadlike strands have been described connecting the aborted fetus to an otherwise normal-appearing amnion. Instead of t,hreadlike, they may be tent shaped, with the apex attached to the body, head, or ends of the fingers or toes. In early intrauterine esistencc, due to a more right-angular attachment of the appendages to the body, contact with thcx amnion might be expected to occur readily t,o the head and digits.’ Wha.t causes these adhesions can only be conjectured. Amniotic aclhesions and resulting fetal deformities a,re known to occur in ectopic gestations wit.h more frequency than in normal gestations. In the term or near-term, otherwise normal intrauterine gestation, these amniotic bands are extremely rare. When they do occur. such bands, arising from the amnion, may be free at the other end, or attached to t,he fetns or to another area of the amnion. Loops may form around portions of the fetus, including digits or portions of extremities, causing corresponding deformities. These strands may entangle the umbilical cord, causing strangulation of t,he cord and intrauterine death. Fetal death may occur ante partum, intrapartum, or post partum. One reported cast was that of a child born alive at term who died shortly thereafter.2 Duncan2 compiled from the world literature 8 cases of fetal dea.th causccl by amniotic strings and added 2 others, one of his own and one of C(ra~cn ant1 &ddes4 in the addendum to his article. The case herewith report,4 brings the total from the world literature to 11.
A
The patient was a 19.pear-old white girl, gravida i, para 0. who was first seen at Ellington Air Force Base on July 9, 1956. At that time she was approximately 34 weeks pregnant. The last normal menstrual period had been Nov. 13, 1955, and t,he expecter1 date of confinement was Aug. 20, 1956. On the last prenatal visit, July 25, the fetal heartbeat was 140, heard in the left lower quadrant, strong and regular. Laborator,v tests were completely withiu normal limits. The Rh factor was negative and the 1~10011 tapes was A. The patient was admitted on July 30 in active labor. She stated that she had not noticed her baby moving for the past four days an<1 the fetal heartbeat could not be 1102
AMNIOTIC
\‘uhlme Number
71 5
heard
at this
delivered shortly
Pig
l.-Amniotic
Fig. becoming surface.
time.
under thereafter
BANDS A macerated
pudendal without
band
Z.-Section a stringlike The opposite
arises
CAUSING stillborn
block anesthesia difficulty.
from umbilical
both
INTRAUTERINE female with
cord and cord, causing
through the separated structure shows amnion torn surface contains
FETAL
infant
weighing
Trilene,
anI1
placenta and strangulation.
6 pounds the
wraps
was
placenta
itself
1103
DEATH
eventually
was
tightly
amniotic membrane twisting on itself cells occurring as a single layer some scattered chorionic trophoblastic
expressed
around
just covering
cells.
the
before one
110-l The umbilical cord presented a brownish-gray ~liscoloration down to a point 4% inches from its insertion in the placenta, where there was a constriction; on the placental side of this point the cord was normal in appearance (Fig. 1). A strand wrapped on itself in places and in other places appearing as a plain string of tissue was found to be bound tightly around the cord three and one half times. At one end this strand fanned out into what appeared grossly to be amniotic membrane attached to both the placenta and the cord near its placental attachment. From the constriction of the cord, the amniotic band emerged as two strands, each of which fanned out into a paper-thin membrane common to both, but free of any attachment to any other structures. Pathological Examination.-It was the opinion of Wilson G, Brown, the chief pathoi ogist at Hermann Hospital, that the separated membrane (Fig. 2) had as one surface a single layer of clearly identifiable amnion cells with cuboidal, oval, or slightly irregular pale-blue nuclei and indistinct cytoplasmic borders. The opposing surface showed an occasional plump cell with acidophilic cytoplasm an<1 small darkly stained nucleolus apIt was believed that the amnion had split parently representing a remnant of chorion. from the adjacent chorion, carrying with it occasional scattered trophoblastic cells.
Comment Amniotic bands can bc deforming as well as fatal. Traumatic tmbryonic amputations have been recognized and reported on sporadically since the very early 1800’s. There was in all probability knowledge concerning t,hem long before then. J,cnnon3 noted that Watkinson in 1825 gave the first report of an intrauterine amputation, but did not record the presence or absence of bands. The left leg had been completely amputated a little above the ankle. The foot was found in the vagina, rat,her well preserved following the prcmature birth of the infant at seven months’ gestation. Over the years numerous theories have been postulated as to the etiology of amniotic bands, including : (1) inff ammation of the amnion ; (2) abnormal disposition of portions of the amnion ; (3) maldevelopment of the amnion (developmental, instead of traumatic) ; (4) environmental influences ; (5) dietetic influences ; (6) rubella. LcnnonS felt that amniotic bands are not adhesions, but are the result of faults in the developing amnion. We agree with him and believe that at least two factors or mechanisms are involved in the formation of these curious strands. First, an adhesive process takes place between an area of amnion and an area of the fetus, or perhaps another part of the amnion. Over a period of time the amnion is stretched, forming sheets or strings of varying shapes. The etiology of the initial adhesion could be abnormal amnion-chorion attachment to or detachment from adjacent structures: decidua or myometrium in intraInuterine pregnancies or adjacent viscera in extrauterine pregnancies. flammation in these areas may play a role. Second, the integrity of the amnion may be disrupted in such a way that it would peel off, twist on itself, and form a string. This might occur as a result of premature rupture of the membranes. Possibly long finger- or toenails might initiate a tear in sites other than the cervical OS. These cases are
Vdume
Number
71
i
AMNIOTIC
BANDS
ChUSTNG
INTRAUTERTNE
so rare and arc so virtually undiagnosable probably only of academic interest.
FETAL
before delivery
DEXTH
that their
110.5
cause is
References Pathology of the Fetus and the Newborn, Chicago, E. L.: Publishers, Inc., p. 533. 2. Duncan, A. S.: J. Obst. & Gynaec. Brit. Emp. 60: 529, 1953. 3. Lennon, G. G.: J. Obst. & Gynaec. Brit. Emp. 60: 830, 1947. 4. Craven, F. WK., and Gedrles, C. J. M.: Brit. Ued. J. 1: 81, 1953. 1. Potter,
1952,
The
Year
Book