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Echogenic fetal bowel in the third trimester associated with trisomy 18
ELSEVIER
European Journal of Obstetrics & Gynecology and Reproductive Biology 67 (1996) 65-67
ossn GYNECOU
Case r e p o r t
Echogenic fetal bowel in the third trimester associated with trisomy 18 H i r o m i H a m a d a * , S u z u k a O k u n o , Y u t a k a Fujiki, N a o k i Y a m a d a , Satoshi S o h d a , Takeshi Kubo Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, lbaraki 305, Japan Received 20 November 1995; revised 13 February 1996; accepted 29 February 1996
Abstract
We present the first case of trisomy 18 in which echogenic fetal bowel was detected in the third trimester after normal echogenicity was documented during the second trimester. Fetal karyotyping should be considered in cases of increased echogenicity of the fetal lower abdomen in the second as well as the third trimester.
Keywords: Prenatal diagnosis; Ultrasound; Echogenic bowel; Third trimester; Trisomy 18
1. Case report
A 29-year-old Japanese woman, gravida 3, para 1, was referred for prenatal care to our department at 9 weeks' gestation. Her first pregnancy ended in spontaneous abortion at 7 weeks' gestation. Her second pregnancy resulted in a full-term uncomplicated vaginal delivery. The family history was unremarkable. Ultrasound examination on referral revealed normal fetal development. No structural anomalies were observed in the fetus during a routine ultrasound examination at 17 weeks' gestation. There was no hyperechoic mass in the fetal lower abdomen. The echogenicity of the fetal lower abdominal area was also normal at 25 weeks' gestation. Routine ultrasound examination at 31 weeks' gestation, however, revealed an echogenic bowel in the fetus (Fig. 1). A ventricular septal defect and a single umbilical artery were also noted. The estimated fetal weight was 1250 g, indicating the presence of intrauterine growth retardation (IUGR). Amniotic fluid index was 95 ram. After being advised of the possible causes of fetal abnormalities and growth retardation, the patient *Corresponding author, Tel.: +81 298 533210; Fax: +81 298 533072.
elected to undergo fetal chromosomal analysis. At 32 weeks' gestation, fetal blood sampling by cordocentesis was performed for fetal karyotyping, and revealed an abnormal 47, XX, +18 chromosome constitution. At gestation for 33 weeks and 2 days, spontaneous premature rupture of membranes led to preterm vaginal delivery of a living female infant weighing 1406 g with an Apgar score of 2 at 1 rain and 5 at 5 min. The infant exhibited a small mouth, micrognathia, low-set ears, overlapping fingers, camptodactyly and club feet. She lived approximately 2 h. Autopsy showed a ventricular septal defect, absence of the right umbilical artery, horseshoe kidneys, and a bicornuate uterus. There were no abnormalities in the gastrointestinal tract and intra-abdominal organs. The cause of the echogenic bowel was not determined. Chromosomal analyses of the infant's peripheral blood lymphocytes confirmed a trisomy 18 karyotype. Both parents had normal karyotypes. 2. Discussion
Echogenic fetal bowel was originally described as a normal variant in the second trimester, but an association between chromosomal abnormalities and sono-
0301-2115/96/$15.00 © 1996 Elsevier Science Ireland Ltd. All rights reserved PII: S0301-2115(96)0243-5
66
1t. Hamada et al./European Journal of Obstetrics & Gynecology and Reproductive Biology 77 (1996) 65-67
Fig. 1. Longitudinal (A) and transverse (B) sonogram of a fetus with trisomy 18 at 31 weeks' gestation. Increased echogenicity is noted in the fetal lower abdomen (arrow).
graphically detected echogenic fetal bowel has recently been described. Nyberg et al. [1] reported a possible relationship between hyperechogenicity in the lower abdomen and trisomy 21 in 94 prenatally diagnosed fetuses. Scioscia et al. [21 described five cases of trisomy 21 and one case of trisomy 18 associated with echogenic bowel in a study of 22 fetuses. Echogenic bowel has been detected on sonography in fetuses with trisomy 13, 18 and 21, triploidy and sex chromosome aberrations during the second trimester [3]. Only one case of trisomy 21 with echogenic bowel in the third trimester has been reported [4]. We present the first case of fetal trisomy 18 associated with third-trimester echogenic bowel, in which this sonographic finding was not detected during the second trimester. Previous reports have suggested an association between echogenic fetal bowel in the third trimester and meconium ileus and/or meconium peritonitis [5]. In our case, the autopsy revealed no findings of meconium ileus and/or meconium peritonitis. We therefore concluded that the echogenic fetal bowel was associated with the abnormal karyotype. The mechanism of increased echogenicity of the lower abdomen in a fetus with trisomy 18 is not clear. Nyberg et al. [3] suggested decreased swallowing, hypoperistalsis, or hypercellular meconium as possible factors. There are two additional explanations for the association between echogenic bowel and trisomy 18. (1) In IUGR, there is redistribution of regional blood flow resulting in mesenteric ischemia and impairment in bowel motility. Meconium becomes more sticky and
dense, and therefore hyperechoic on ultrasonography [6]. This is of particular relevance in our case because IUGR was presented. (2) Echogenic fetal bowel is associated with fetal swallowing of bloody amniotic fluid after intra-amniotic bleeding [7,8]. Intra-amniotic bleeding could be the result of abnormal placentation, which is commonly found in association with fetal aneuploidy. The present case indicates that echogenic fetal bowel in the third trimester could be associated with fetal trisomy 18. Although further studies of larger populations with third-trimester echogenic fetal bowel are needed, fetal karyotyping should be considered in cases of increased echogenicity of the fetal lower abdomen in the second as well as the third trimester.
References [1]
[2]
[3]
[41
[5]
Nyberg DA, Resta RG, Lnthy DA, Hickok DE, Mahony BS, Hirseh JH. Prenatal sonographic findings of Down syndrome: review of 94 cases. Obstet Gynecol 1990; 76: 370-377. Scioscia AL, Pretorius DH, Budorick NE, Cahill TC, Axelrod FT, Leopold GR. Second-trimester echogenic bowel and chromosomal abnormalities. Am J Obstet Gynecol 1992; 167: 889-894. Nyberg DA, Dubinsky T, Resta RG, Mahony BS, Hickok DE, Luthy DA. Echogenic fetal bowel during the second trimester: clinical importance. Radiology 1993; 188: 527-531. Sepulveda W, Bower S, Fisk NM. Third-trimester hyperechogcnic bowel in Down syndrome. Am J Obstet Gynecol 1995; 172:210-211. Lince DM, Pretorius DH, Manco-Johnson ML, Manchester D,
H. Hamada et al. / European Journal of Obstetrics & Gynecology and Reproductive Biology 77 (1996) 65-67
[6]
[71
Clewell WH. The clinical significance of increased ecbogenicity in the fetal abdomen. Am J Roentgenol 1985; 145: 683-686. Ewer AK, McHugn JM, Chapman S, Newell SJ. Fetal echogenic gut: a marker of intrauterine gut ischaemia? Arch Dis Child 1993; 69: 510-513. Sepulveda W, Hollingsworth J, Bower S, Vaughan J[, Fisk NM. Fetal hypercchogenic bowel following intra-amniotic bleeding. Obstet Gynecol 1994; 83: 947-950.
lSl
67
Sepulveda W, Reid R, Prendiville O, Chapman R, Fisk NM. Second trimester echogenic bowel and intra-amniotic bleeding: correlation between small bowel echogenicity and amniotic fluid spcctrophotometry at 410 nm [abstract]. Am J Obstet Gynecol 1995; 172: 395.
European Journal of Obstetrics & Gynecology and Reproductive Biology 67 (1996) 65-67
ossn GYNECOU
Case r e p o r t
Echogenic fetal bowel in the third trimester associated with trisomy 18 H i r o m i H a m a d a * , S u z u k a O k u n o , Y u t a k a Fujiki, N a o k i Y a m a d a , Satoshi S o h d a , Takeshi Kubo Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, lbaraki 305, Japan Received 20 November 1995; revised 13 February 1996; accepted 29 February 1996
Abstract
We present the first case of trisomy 18 in which echogenic fetal bowel was detected in the third trimester after normal echogenicity was documented during the second trimester. Fetal karyotyping should be considered in cases of increased echogenicity of the fetal lower abdomen in the second as well as the third trimester.
Keywords: Prenatal diagnosis; Ultrasound; Echogenic bowel; Third trimester; Trisomy 18
1. Case report
A 29-year-old Japanese woman, gravida 3, para 1, was referred for prenatal care to our department at 9 weeks' gestation. Her first pregnancy ended in spontaneous abortion at 7 weeks' gestation. Her second pregnancy resulted in a full-term uncomplicated vaginal delivery. The family history was unremarkable. Ultrasound examination on referral revealed normal fetal development. No structural anomalies were observed in the fetus during a routine ultrasound examination at 17 weeks' gestation. There was no hyperechoic mass in the fetal lower abdomen. The echogenicity of the fetal lower abdominal area was also normal at 25 weeks' gestation. Routine ultrasound examination at 31 weeks' gestation, however, revealed an echogenic bowel in the fetus (Fig. 1). A ventricular septal defect and a single umbilical artery were also noted. The estimated fetal weight was 1250 g, indicating the presence of intrauterine growth retardation (IUGR). Amniotic fluid index was 95 ram. After being advised of the possible causes of fetal abnormalities and growth retardation, the patient *Corresponding author, Tel.: +81 298 533210; Fax: +81 298 533072.
elected to undergo fetal chromosomal analysis. At 32 weeks' gestation, fetal blood sampling by cordocentesis was performed for fetal karyotyping, and revealed an abnormal 47, XX, +18 chromosome constitution. At gestation for 33 weeks and 2 days, spontaneous premature rupture of membranes led to preterm vaginal delivery of a living female infant weighing 1406 g with an Apgar score of 2 at 1 rain and 5 at 5 min. The infant exhibited a small mouth, micrognathia, low-set ears, overlapping fingers, camptodactyly and club feet. She lived approximately 2 h. Autopsy showed a ventricular septal defect, absence of the right umbilical artery, horseshoe kidneys, and a bicornuate uterus. There were no abnormalities in the gastrointestinal tract and intra-abdominal organs. The cause of the echogenic bowel was not determined. Chromosomal analyses of the infant's peripheral blood lymphocytes confirmed a trisomy 18 karyotype. Both parents had normal karyotypes. 2. Discussion
Echogenic fetal bowel was originally described as a normal variant in the second trimester, but an association between chromosomal abnormalities and sono-
0301-2115/96/$15.00 © 1996 Elsevier Science Ireland Ltd. All rights reserved PII: S0301-2115(96)0243-5
66
1t. Hamada et al./European Journal of Obstetrics & Gynecology and Reproductive Biology 77 (1996) 65-67
Fig. 1. Longitudinal (A) and transverse (B) sonogram of a fetus with trisomy 18 at 31 weeks' gestation. Increased echogenicity is noted in the fetal lower abdomen (arrow).
graphically detected echogenic fetal bowel has recently been described. Nyberg et al. [1] reported a possible relationship between hyperechogenicity in the lower abdomen and trisomy 21 in 94 prenatally diagnosed fetuses. Scioscia et al. [21 described five cases of trisomy 21 and one case of trisomy 18 associated with echogenic bowel in a study of 22 fetuses. Echogenic bowel has been detected on sonography in fetuses with trisomy 13, 18 and 21, triploidy and sex chromosome aberrations during the second trimester [3]. Only one case of trisomy 21 with echogenic bowel in the third trimester has been reported [4]. We present the first case of fetal trisomy 18 associated with third-trimester echogenic bowel, in which this sonographic finding was not detected during the second trimester. Previous reports have suggested an association between echogenic fetal bowel in the third trimester and meconium ileus and/or meconium peritonitis [5]. In our case, the autopsy revealed no findings of meconium ileus and/or meconium peritonitis. We therefore concluded that the echogenic fetal bowel was associated with the abnormal karyotype. The mechanism of increased echogenicity of the lower abdomen in a fetus with trisomy 18 is not clear. Nyberg et al. [3] suggested decreased swallowing, hypoperistalsis, or hypercellular meconium as possible factors. There are two additional explanations for the association between echogenic bowel and trisomy 18. (1) In IUGR, there is redistribution of regional blood flow resulting in mesenteric ischemia and impairment in bowel motility. Meconium becomes more sticky and
dense, and therefore hyperechoic on ultrasonography [6]. This is of particular relevance in our case because IUGR was presented. (2) Echogenic fetal bowel is associated with fetal swallowing of bloody amniotic fluid after intra-amniotic bleeding [7,8]. Intra-amniotic bleeding could be the result of abnormal placentation, which is commonly found in association with fetal aneuploidy. The present case indicates that echogenic fetal bowel in the third trimester could be associated with fetal trisomy 18. Although further studies of larger populations with third-trimester echogenic fetal bowel are needed, fetal karyotyping should be considered in cases of increased echogenicity of the fetal lower abdomen in the second as well as the third trimester.
References [1]
[2]
[3]
[41
[5]
Nyberg DA, Resta RG, Lnthy DA, Hickok DE, Mahony BS, Hirseh JH. Prenatal sonographic findings of Down syndrome: review of 94 cases. Obstet Gynecol 1990; 76: 370-377. Scioscia AL, Pretorius DH, Budorick NE, Cahill TC, Axelrod FT, Leopold GR. Second-trimester echogenic bowel and chromosomal abnormalities. Am J Obstet Gynecol 1992; 167: 889-894. Nyberg DA, Dubinsky T, Resta RG, Mahony BS, Hickok DE, Luthy DA. Echogenic fetal bowel during the second trimester: clinical importance. Radiology 1993; 188: 527-531. Sepulveda W, Bower S, Fisk NM. Third-trimester hyperechogcnic bowel in Down syndrome. Am J Obstet Gynecol 1995; 172:210-211. Lince DM, Pretorius DH, Manco-Johnson ML, Manchester D,
H. Hamada et al. / European Journal of Obstetrics & Gynecology and Reproductive Biology 77 (1996) 65-67
[6]
[71
Clewell WH. The clinical significance of increased ecbogenicity in the fetal abdomen. Am J Roentgenol 1985; 145: 683-686. Ewer AK, McHugn JM, Chapman S, Newell SJ. Fetal echogenic gut: a marker of intrauterine gut ischaemia? Arch Dis Child 1993; 69: 510-513. Sepulveda W, Hollingsworth J, Bower S, Vaughan J[, Fisk NM. Fetal hypercchogenic bowel following intra-amniotic bleeding. Obstet Gynecol 1994; 83: 947-950.
lSl
67
Sepulveda W, Reid R, Prendiville O, Chapman R, Fisk NM. Second trimester echogenic bowel and intra-amniotic bleeding: correlation between small bowel echogenicity and amniotic fluid spcctrophotometry at 410 nm [abstract]. Am J Obstet Gynecol 1995; 172: 395.