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Thoracopygopagus tripus: An unusual form of conjoined twins
Communications
Table
II. Changes
in congenital
h~utmd
oral-cleft
1963-70 i-ate per 10,000
agv
< 20 20-24 25-2<1 30-34 35-39 40+ Total Total Total
incidence
rates by maternal 197i-73 rate per 10,000
12.36 11.94 12.46 12.12 13.54 15.81 12.38 no. of oral-cleft no. of live births
*Change
in rate
births
divided
9.89 9.37 9.67 12.32 12.50 12.79 10.15
1,668 1,346.990 by rate
(or
other
spontaneously
occurrence
ol’ oral
which
are induced clef’ts
in
to
oral
c.lefts
abnormalities clefts caven
compared
with
are associated
would
to abortion.
spontaneous
noteworthy in this connection, quency of threatened abortion
have
The
aborGons
is
as is the higher frein pregnancies leading controls.
with
Chromosomal
some cases of oral
and with risk of spontaneous abortion. Thus, without induced abortions some fetuses with oral would never survive to birth. Hence, any reduc-
cleft tion in oral cleft incidence abortions
may
be difficult
age Change in I-utr
Per cmi change *
-2.47 -2,57 -2.79 +0.20 -1.04 ~-3.02 -2.23
-20.0 -21.5 -22.4 + 1.7 -7.7 -19.1 ~ -18.0
Induced liw
abw:mn.~ fwr 1,000 l~zrlh~. 197! -73 ~501 189 IlO 12-j 338 61 I $77
in 1963-70.
malformations)
aborted
735
416 409,955
environmental changes may have occurred that affected several types of malformations. A more specific test of the hypothesis of an effect of induced abortions on incidence rate of oral clefts involves analysis by maternal age. If legalized abortion had an effect, the reduction in the rate should be greatest at the extremes of maternal age, since induced abortions are more frequent at these ages. Table II shows the ratio of induced abortions to live births in upstate New York among upstate residents. Comparing 1963-1970 l$ith 1971-1973, the magnitude of the decline in the oral cleft rate is approximately equal in the first three maternal age categories (<20,20-24, and %-%I), whereas the induced abortion/live birth ratio declines sharply after age 19. The decline in the oral cleft rate is greater at maternal age 40 and over than at 30-39 vrars. but the over-all correspondence between the per cent change in oral cleft rate and the abortion rate is not very close. Thus, analysis of oral cleft incidence ra[c by maternal age before and after the 1970 abortion law does not provide strong support for a simple causal rela&nship. The pattern of decline in oral clefts by maternal age (Table 11) could still conceivably be explained by selective removal by induced abortion of fetuses at high risk for oral clefts due to the effects of maternal stress, since reasons f’or seeking abortion may vary with maternal age. For example, psychological stress may be more frequent, or :* more comtnon incentive for abortion. at certain maternal ages. Finally, it should be noted that some fetuses with oral clefts
WIbrief
at birth to detect.
related
to induced
REFERENCES
1. Fraser, F. C., and Warburtnn, 395, 1964. 2. Saxen, I.: lnt. J. Epidemiol.
D.: Plast. 3: 263.
Reconstr.
Surg.
33:
1974.
Thoracopygopagus tripus: An unusual form of conjoined twins EDWARD
M.
NICHOLAS
LIGHTEN,
Ohio State lrniwmity
THk:
p,4~b1oLoGIc
joined twins and obstetric
M.D.
J. TETERISS
M.D.
Hospitalv
Columbus,
anatomy
is presented. management
Ohio
of a rare torni
The criteria are revie\+ed.
for
of conantenatal
A 31-year-old Gl, PO, ABO Caucasian tlurxe, gravida I, para O* with a blood type of AB-negative, was tollowed at the Ohio State University Hospital’s obstetric c-linic from her fourteenth week of gestation, She presented on February 12, 1974. with a 12 hour history of spontaneously ruptured membranes. No history of exposure to any known teratogens was elicited. No prenatal drug or viral exposure \qas extracted. Family hisjory was negative for twinm~ig; t.wins were not suspected prior to admission. The patient’s last menstrual period was on July 14, 1973; the estimated date of confinement was April 22, 1974. On admission the patient reported extensive fetal movement in the lower quadrants. Phvsical examination \
Reprint Hospital. Kentucky
address: Doctor’s 40207.
Edward Building.
M. Lichten, M.D.. blast Baptist 3950 Kresge ti.ay, l.o~Gsvillc.
736
Communications
in brief
November Am. J. Obstet.
15, 1976 Gvnecd
Fig. 2. Internal anatomy showing fused liver and two stomachs with sinus inversus of twin “A”.
Fig. 1. Gross pathology leg.
of conjoined
twins with fused third
descent did not occur. Cesarean section was performed through a low transverse cervical incision. The fetuses were delivered with ease with no evidence of respiratory or cardiac activity. The combined fetal weight was 2,850 grams. The bodies were first fused at the sternum with four clavicles. An anterior and a posterior sternum were noted with a single pericardial space and fused common liver. Twin “A” had a right-sided aortic arch, with an anomalous origin of the left subclavian off the descending portion of the arch, and a left-sided superior vena cava, with a prominent right-sided brachiocephalic vein crossing the midline. Twin “B” had a normal left-sided aortic arch, with an anomalous origin of the right subclavian artery passing dorsally to the esophagus and trachea, Twin “B” demonstrated a patent ductus arteriosus; Twin “A” showed 90 per cent occlusion. A single umbilical vein noted entering the region of the porta hepatis communicated with the inferior vena cava of Twin “A” and could be dissected through the sinus intermedius to the regious on the portal vein of Twin “B.” The respiratory system contained normal structures, with “A” having three lobes on the left and two on its
right; “B”, two on the left and three on the right. However, the gastrointestinal tract of Twin “A” showed situs inversus in reference to a normalpositioned “B”. Two separate jejunae were noted, The rectal regions in both gastrointestinal systems ended in a blind pouch. The urinary system was unusual in that both twins had two kidneys, two ureters, and a bladder, but the left kidney of Twin “B” communicated with an anterior bladder as did the right kidney of Twin “A.” The posterior bladder emptied the remaining two kidneys. The urethras connected with the perineum through a common opening. The genital system demonstrated an anterior vagina which ended as a blind pouch. It joined with the anterior bladder through a urethal-vaginal listula. The cervix, bicornuate uterus, two oviducts, and two ovaries were separated from the posterior genital system by the rectal pouches. The posterior genital system had a double imperforate vagina. The left one communicated with the posterior bladder through a urethralvaginal fistula. The uterus was bicornuate with two oviducts and ovaries. A double cervix was noted. The right ureter of Twin “B” crossed the rear surface of the back uterus to join the posterior bladder. The twins shared an ilium from which the common third leg originated. The antenatal diagnosis of conjoined twins was made radiographically based on Gray’s criteria. Vaginal delivery was noted in 60 per cent of reported cases and should be considered if gross structural abnormakties were to be discovered. If a difficult delivery was expected due to birth weight over 8 pounds, or if surgical
Volume Number
126 fi
Communications
correction was considered, cesarean section was probably the best mode of delivery. The majority of pygopagus and ischiopagus twins with common pelves would have the cross-communicating urinary system described in this case report. If surgical intervention could be postponed, surgical prognosis was greatly improved. Failure of one infant was indication for immediate intervention. REFERENCES 1. Guttmacher, 1967. 2. Zimmerman,
A. F., and A. A.: Birth
Nichols,
B. L.:
Defects
Birth
Defects
3: 3,
3: 18, 1967.
The pfepartum diagnosis of conjoined twin8 by the use of diagnostic ultrasound ROBERT CURTIS MICHAEL
L. L.
WILSON, CETRULO. S.
SHAUB,
M.D. M.D. M.D.
Departments of Radiohgy and Obstehics and Gynecology, Los Angeles Countyllhiuersity of Sotihern Calfornia Medzkal Center, Los Angeles, Cal$wnia THE EARLIEST known and recorded case ofconjoined (Siamese) twins was in Kent, England, in 1100 A.D. They were known as the Biddenden Twins and lived to the third decade of life. Since that time, approximately 500 cases of conjoined twins have been described’* ’ and their incidence has been estimated at one in every 50,000 deliveries to one in every 100,000 deliveries.13 ’ The rare occurrence of such an anomaly makes the statistics difficult to rely upon. Prior to 1950, only four cases had been diagnosed or strongly suspected prior to labor.lz ’ The ultrasound findings in conjoined twins have never before been described in the antepartum period and are included herein. Margarita M. was a 34-year-old Mexican-American woman, gravida 5, para 4, with four normal children. The previous pregnancies were uncomplicated and produced term-sized infants: 3 boys and I girl. Her last normal menstrual period was on January 4, 1974, with an expected date of confinement of October 11, 1974. There was no consanguinity but there was a strong family history of twins. Following the last delivery. in 1971, a right unilateral tubal ligation was performed. The left adnexa was described as being “surgically absent.” The patient was followed at an outside clinic and was first seen at 10 weeks’ gestation. The uterus at that time was felt to be compatible with a 14 week gestation. Two other subsequent
Reprint requests: Robert L. Wilson, M.D., Chief, Diagnostic Ultrasound !jection, Department of Radiology, Department of Health Services, Los Angeles County-University of Southern California, 1100 N. Mission Rd., Los Angeles, Calif. 90033.
in brief
737
examinations yielded a fundal height larger than the gestational age. At 35 weeks’ gestation, the fundal height measured 41 cm. and a radiograph was obtained to exclude the possibility of twins. Two fetuses were identified, both in the breech position. m fae. The patient was then referred to the L. A. County/USC Medical Center for further care and diagnosis, including an ultrasound examination. The ultrasound procedure performed on Septenibcr 20, 1974, demonstrated two fetuses in the breech pc>sition with an estimated mean gescational age of approximately 37 weeks. Two separate, distinct thoraces could not IX> demonstrated and only one fetal heart rate, in the midline~ t,ould be heard on Doppler examination. The diagnosis of conjoined (Siamese) twins was verbally entertained, tmr rhe radiogmph was not available for confirmation. In addition to the usual prenatal medications, the patient was placed on Ritodrine HCI, a beta-sympathomimetic agent, at 35 weeks’ gestation. The Ritodrine ti;ib administered prophylactically in order to reduce the risk of premature labor. The patient entered the emergency ro~~rn on October 12, 1974, complaining of spontaneous uterine contractions with spontaneous rupture of membranes shortly Lhereafter. Subsequent labor produced a double footlittg breech and a primary cesarean section was elected. ‘The palient was taken to the operating room and prepared in the usual manner, Induction of general anesthesia to delivery time requirecl 12 minutes. Female thoracopagus twins were delivered through a low transverse incision without extension 0, complication. The left adnexa was present and a left unilateral tubal ligation was performed. The Apgar scores were 1 at 1 minute and 4 at 5 minutes. The combined weight was 4,.590 grams. Soon after delivery, the babies were placed on separate respirators which alternately ventilated them. Numerous complications developed and their clinical status rapidly deteriorated. The babies died approximately 12 minutes apart on Ocn~ber 1.5, 1974. The complete autopsy findings are beyond the scope and purpose of this report, but of interest was the finding of a single pericardium and a common right ventric,le. ‘I%e twins were joined from the level of the xyphoid sterni ttl the lowe midabdomen in the region of the hylmgastriutrl.
The case presented allows confirmatory radiographic and ultrasonographic findings to be summarized for the first rime in an instance ot thoracopagus conjoined twins. .4lthough con,joined twins are a rare entity, thoracopagus is, hi far, the most common form of this anoma1y.l. ’ AI incidental autopsy finding in many of the reported thoracopagus twins was the occurence of a single. common pericardium.‘, ’ When confronted with the ultrasound findings of a single trunk outline, one persistent heart rate by Doppler examination, and the radiographic criteria described by Gray, ‘, ’ the physician should bc highly suspicious of the presence of thoracopagus twins. Other types of conjoined twins will alter these findings accordingly.
REFERENCES 1. Tan, K. L,, Goon, S. M., Salmon, Obstet. Gynecol. Stand. 50: 373, 2. Birth Defects Original Article dation-March of Dimes 3: No. 1,
Y., and Wee, J. H.: Acta 1971. Series, National FounApril 1967.
Table
II. Changes
in congenital
h~utmd
oral-cleft
1963-70 i-ate per 10,000
agv
< 20 20-24 25-2<1 30-34 35-39 40+ Total Total Total
incidence
rates by maternal 197i-73 rate per 10,000
12.36 11.94 12.46 12.12 13.54 15.81 12.38 no. of oral-cleft no. of live births
*Change
in rate
births
divided
9.89 9.37 9.67 12.32 12.50 12.79 10.15
1,668 1,346.990 by rate
(or
other
spontaneously
occurrence
ol’ oral
which
are induced clef’ts
in
to
oral
c.lefts
abnormalities clefts caven
compared
with
are associated
would
to abortion.
spontaneous
noteworthy in this connection, quency of threatened abortion
have
The
aborGons
is
as is the higher frein pregnancies leading controls.
with
Chromosomal
some cases of oral
and with risk of spontaneous abortion. Thus, without induced abortions some fetuses with oral would never survive to birth. Hence, any reduc-
cleft tion in oral cleft incidence abortions
may
be difficult
age Change in I-utr
Per cmi change *
-2.47 -2,57 -2.79 +0.20 -1.04 ~-3.02 -2.23
-20.0 -21.5 -22.4 + 1.7 -7.7 -19.1 ~ -18.0
Induced liw
abw:mn.~ fwr 1,000 l~zrlh~. 197! -73 ~501 189 IlO 12-j 338 61 I $77
in 1963-70.
malformations)
aborted
735
416 409,955
environmental changes may have occurred that affected several types of malformations. A more specific test of the hypothesis of an effect of induced abortions on incidence rate of oral clefts involves analysis by maternal age. If legalized abortion had an effect, the reduction in the rate should be greatest at the extremes of maternal age, since induced abortions are more frequent at these ages. Table II shows the ratio of induced abortions to live births in upstate New York among upstate residents. Comparing 1963-1970 l$ith 1971-1973, the magnitude of the decline in the oral cleft rate is approximately equal in the first three maternal age categories (<20,20-24, and %-%I), whereas the induced abortion/live birth ratio declines sharply after age 19. The decline in the oral cleft rate is greater at maternal age 40 and over than at 30-39 vrars. but the over-all correspondence between the per cent change in oral cleft rate and the abortion rate is not very close. Thus, analysis of oral cleft incidence ra[c by maternal age before and after the 1970 abortion law does not provide strong support for a simple causal rela&nship. The pattern of decline in oral clefts by maternal age (Table 11) could still conceivably be explained by selective removal by induced abortion of fetuses at high risk for oral clefts due to the effects of maternal stress, since reasons f’or seeking abortion may vary with maternal age. For example, psychological stress may be more frequent, or :* more comtnon incentive for abortion. at certain maternal ages. Finally, it should be noted that some fetuses with oral clefts
WIbrief
at birth to detect.
related
to induced
REFERENCES
1. Fraser, F. C., and Warburtnn, 395, 1964. 2. Saxen, I.: lnt. J. Epidemiol.
D.: Plast. 3: 263.
Reconstr.
Surg.
33:
1974.
Thoracopygopagus tripus: An unusual form of conjoined twins EDWARD
M.
NICHOLAS
LIGHTEN,
Ohio State lrniwmity
THk:
p,4~b1oLoGIc
joined twins and obstetric
M.D.
J. TETERISS
M.D.
Hospitalv
Columbus,
anatomy
is presented. management
Ohio
of a rare torni
The criteria are revie\+ed.
for
of conantenatal
A 31-year-old Gl, PO, ABO Caucasian tlurxe, gravida I, para O* with a blood type of AB-negative, was tollowed at the Ohio State University Hospital’s obstetric c-linic from her fourteenth week of gestation, She presented on February 12, 1974. with a 12 hour history of spontaneously ruptured membranes. No history of exposure to any known teratogens was elicited. No prenatal drug or viral exposure \qas extracted. Family hisjory was negative for twinm~ig; t.wins were not suspected prior to admission. The patient’s last menstrual period was on July 14, 1973; the estimated date of confinement was April 22, 1974. On admission the patient reported extensive fetal movement in the lower quadrants. Phvsical examination \
Reprint Hospital. Kentucky
address: Doctor’s 40207.
Edward Building.
M. Lichten, M.D.. blast Baptist 3950 Kresge ti.ay, l.o~Gsvillc.
736
Communications
in brief
November Am. J. Obstet.
15, 1976 Gvnecd
Fig. 2. Internal anatomy showing fused liver and two stomachs with sinus inversus of twin “A”.
Fig. 1. Gross pathology leg.
of conjoined
twins with fused third
descent did not occur. Cesarean section was performed through a low transverse cervical incision. The fetuses were delivered with ease with no evidence of respiratory or cardiac activity. The combined fetal weight was 2,850 grams. The bodies were first fused at the sternum with four clavicles. An anterior and a posterior sternum were noted with a single pericardial space and fused common liver. Twin “A” had a right-sided aortic arch, with an anomalous origin of the left subclavian off the descending portion of the arch, and a left-sided superior vena cava, with a prominent right-sided brachiocephalic vein crossing the midline. Twin “B” had a normal left-sided aortic arch, with an anomalous origin of the right subclavian artery passing dorsally to the esophagus and trachea, Twin “B” demonstrated a patent ductus arteriosus; Twin “A” showed 90 per cent occlusion. A single umbilical vein noted entering the region of the porta hepatis communicated with the inferior vena cava of Twin “A” and could be dissected through the sinus intermedius to the regious on the portal vein of Twin “B.” The respiratory system contained normal structures, with “A” having three lobes on the left and two on its
right; “B”, two on the left and three on the right. However, the gastrointestinal tract of Twin “A” showed situs inversus in reference to a normalpositioned “B”. Two separate jejunae were noted, The rectal regions in both gastrointestinal systems ended in a blind pouch. The urinary system was unusual in that both twins had two kidneys, two ureters, and a bladder, but the left kidney of Twin “B” communicated with an anterior bladder as did the right kidney of Twin “A.” The posterior bladder emptied the remaining two kidneys. The urethras connected with the perineum through a common opening. The genital system demonstrated an anterior vagina which ended as a blind pouch. It joined with the anterior bladder through a urethal-vaginal listula. The cervix, bicornuate uterus, two oviducts, and two ovaries were separated from the posterior genital system by the rectal pouches. The posterior genital system had a double imperforate vagina. The left one communicated with the posterior bladder through a urethralvaginal fistula. The uterus was bicornuate with two oviducts and ovaries. A double cervix was noted. The right ureter of Twin “B” crossed the rear surface of the back uterus to join the posterior bladder. The twins shared an ilium from which the common third leg originated. The antenatal diagnosis of conjoined twins was made radiographically based on Gray’s criteria. Vaginal delivery was noted in 60 per cent of reported cases and should be considered if gross structural abnormakties were to be discovered. If a difficult delivery was expected due to birth weight over 8 pounds, or if surgical
Volume Number
126 fi
Communications
correction was considered, cesarean section was probably the best mode of delivery. The majority of pygopagus and ischiopagus twins with common pelves would have the cross-communicating urinary system described in this case report. If surgical intervention could be postponed, surgical prognosis was greatly improved. Failure of one infant was indication for immediate intervention. REFERENCES 1. Guttmacher, 1967. 2. Zimmerman,
A. F., and A. A.: Birth
Nichols,
B. L.:
Defects
Birth
Defects
3: 3,
3: 18, 1967.
The pfepartum diagnosis of conjoined twin8 by the use of diagnostic ultrasound ROBERT CURTIS MICHAEL
L. L.
WILSON, CETRULO. S.
SHAUB,
M.D. M.D. M.D.
Departments of Radiohgy and Obstehics and Gynecology, Los Angeles Countyllhiuersity of Sotihern Calfornia Medzkal Center, Los Angeles, Cal$wnia THE EARLIEST known and recorded case ofconjoined (Siamese) twins was in Kent, England, in 1100 A.D. They were known as the Biddenden Twins and lived to the third decade of life. Since that time, approximately 500 cases of conjoined twins have been described’* ’ and their incidence has been estimated at one in every 50,000 deliveries to one in every 100,000 deliveries.13 ’ The rare occurrence of such an anomaly makes the statistics difficult to rely upon. Prior to 1950, only four cases had been diagnosed or strongly suspected prior to labor.lz ’ The ultrasound findings in conjoined twins have never before been described in the antepartum period and are included herein. Margarita M. was a 34-year-old Mexican-American woman, gravida 5, para 4, with four normal children. The previous pregnancies were uncomplicated and produced term-sized infants: 3 boys and I girl. Her last normal menstrual period was on January 4, 1974, with an expected date of confinement of October 11, 1974. There was no consanguinity but there was a strong family history of twins. Following the last delivery. in 1971, a right unilateral tubal ligation was performed. The left adnexa was described as being “surgically absent.” The patient was followed at an outside clinic and was first seen at 10 weeks’ gestation. The uterus at that time was felt to be compatible with a 14 week gestation. Two other subsequent
Reprint requests: Robert L. Wilson, M.D., Chief, Diagnostic Ultrasound !jection, Department of Radiology, Department of Health Services, Los Angeles County-University of Southern California, 1100 N. Mission Rd., Los Angeles, Calif. 90033.
in brief
737
examinations yielded a fundal height larger than the gestational age. At 35 weeks’ gestation, the fundal height measured 41 cm. and a radiograph was obtained to exclude the possibility of twins. Two fetuses were identified, both in the breech position. m fae. The patient was then referred to the L. A. County/USC Medical Center for further care and diagnosis, including an ultrasound examination. The ultrasound procedure performed on Septenibcr 20, 1974, demonstrated two fetuses in the breech pc>sition with an estimated mean gescational age of approximately 37 weeks. Two separate, distinct thoraces could not IX> demonstrated and only one fetal heart rate, in the midline~ t,ould be heard on Doppler examination. The diagnosis of conjoined (Siamese) twins was verbally entertained, tmr rhe radiogmph was not available for confirmation. In addition to the usual prenatal medications, the patient was placed on Ritodrine HCI, a beta-sympathomimetic agent, at 35 weeks’ gestation. The Ritodrine ti;ib administered prophylactically in order to reduce the risk of premature labor. The patient entered the emergency ro~~rn on October 12, 1974, complaining of spontaneous uterine contractions with spontaneous rupture of membranes shortly Lhereafter. Subsequent labor produced a double footlittg breech and a primary cesarean section was elected. ‘The palient was taken to the operating room and prepared in the usual manner, Induction of general anesthesia to delivery time requirecl 12 minutes. Female thoracopagus twins were delivered through a low transverse incision without extension 0, complication. The left adnexa was present and a left unilateral tubal ligation was performed. The Apgar scores were 1 at 1 minute and 4 at 5 minutes. The combined weight was 4,.590 grams. Soon after delivery, the babies were placed on separate respirators which alternately ventilated them. Numerous complications developed and their clinical status rapidly deteriorated. The babies died approximately 12 minutes apart on Ocn~ber 1.5, 1974. The complete autopsy findings are beyond the scope and purpose of this report, but of interest was the finding of a single pericardium and a common right ventric,le. ‘I%e twins were joined from the level of the xyphoid sterni ttl the lowe midabdomen in the region of the hylmgastriutrl.
The case presented allows confirmatory radiographic and ultrasonographic findings to be summarized for the first rime in an instance ot thoracopagus conjoined twins. .4lthough con,joined twins are a rare entity, thoracopagus is, hi far, the most common form of this anoma1y.l. ’ AI incidental autopsy finding in many of the reported thoracopagus twins was the occurence of a single. common pericardium.‘, ’ When confronted with the ultrasound findings of a single trunk outline, one persistent heart rate by Doppler examination, and the radiographic criteria described by Gray, ‘, ’ the physician should bc highly suspicious of the presence of thoracopagus twins. Other types of conjoined twins will alter these findings accordingly.
REFERENCES 1. Tan, K. L,, Goon, S. M., Salmon, Obstet. Gynecol. Stand. 50: 373, 2. Birth Defects Original Article dation-March of Dimes 3: No. 1,
Y., and Wee, J. H.: Acta 1971. Series, National FounApril 1967.