Antenatal Ultrasonic Demonstration of Fetal
Bowel 1
Ultrasound
Timothy G. Lee, M.D., and Bill H. Warren, M.D.2 Although ultrasound evaluation of the adult gastrointestinal tract is largely impossible because of bowel gas, the fetal bowel is fluid-filled and therefore not subject to this limitation. In our experience, the fetal bowel pattern can be recognized and antenatal abnormalities detected. INDEX TERMS: (Fetus, amniotic sac, ultrasonography, 8[56].1298). Fetus, ultrasound • Intestines, ultrasound studies
Radiology 124:471-474, August 1977
A NTENATAL
DIAGNOSES by ultrasound include early embryonic malformations (4), central nervous system abnormalities (1, 2, 5, 7, 9), renal abnormalities (3, 6, 9), ovarian cysts (6, 11), and cystic lymphangioma (10). To our knowledge, only one case of an antenatal diagnosis of fetal bowel abnormality has been reported (8), although bowel involvement was not recognized until after birth. We have found that the fetal bowel pattern can be recognized antenatally, and the purpose of this paper is to show that differentiation of normal from abnormal bowel pattern is possible.
M
Fig. 1. Sagittal scan shows fluid-filled stomach (8) under the left hemidiaphragm.
METHOD
The following cases were encountered during routine obstetrical scanning of the maternal abdomen for biparietal diameter, placental localization, and fetal position, using a standard commercially available gray scale B-scan unit and 2.25 MHz transducer. Additional scans directed at the fetal abdomen were obtained when abnormal findings were noted.
and polyhydramnios. Fetal bowel was seen floating in ascitic fluid (Fig. 4). The fetal liver could also be seen separated by fluid from the lateral abdominal wall. CASE II. P.H., an 18-year-old gravida II, Para 1, was referred for follow-up ultrasound examination because of being large for dates. Ultrasound showed a 35-week fetus. Multiple dilated tubular fluid-filled structures in the fetal abdomen were noted and believed to be dilated bowel loops. Because these findings were persistent, bowel obstruction was suspected (Fig. 5, A and B). Amniocentesis showed a meconium-stained aspirate positive for anti-Kell antibodies. [These are minor blood subgroups and may cause fetal maternal blood incompatibility.] The ultrasound observations were confirmed immediately postpartum by an abdominal radtoqraph; which showed multiple dilated loops of bowel; a barium enema revealed a malrotated microcolon (Fig. 5, C and D). At surgery, jejunal atresia and a "Christmas tree" or "apple peel" type of deformity of the small bowel were discovered.
NORMAL EXAMINATIONS I. L.A., a 20-year-old gravida I, was referred for ultrasound examination because of uncertain dates. Ultrasound showed a 28.5-week fetus. A fluid-filled stomach was also seen (Fig. 1). II. D.W., a 17-year-old gravida I, was referred for ultrasound examination because of premature labor. Ultrasound showed a 29-week fetus. A changing fetal bowel pattern was noted, with emptying of the stomach and filling of another fluid structure, probably the duodenum (Fig. 2, A and B).
III. L.F., a 20-year-old gravida III, Para 2, was referred for ultrasound examination because of repeat Caesarean section. Ultrasound showed a 35-week fetus. Fluid-filled loops were seen. The pattern of these loops changed with time, characteristic of bowel (Fig. 3, A and B).
CASE III. D.F., a 19-year-old gravida I, had premature rupture of membranes. Ultrasound revealed a 34-week fetus. In addition, two fluid-filled tubular structures outside of the fetal abdomen were noted (Fig. 6, A and B), and the possibility of herniated bowel loops secondary to gastroschisis or omphalocele was suggested. A large, fluid-filled mass was also noted inside the fetal abdomen and the possibility of a bowel, renal, or pelvic origin of the mass was raised (Fig. 6, A and C). Two hours after rupture of membranes, a meconium-stained infant was delivered vaginally. Multiple bowel loops protruded through a defect
CASE REPORTS CASE I. K. F., a 17-year-old gravida I, was referred because of preeclampsia and suspected twins. Ultrasound showed a hydropic fetus
1 From the Department of Diagnostic Radiology, University of Oregon Health Sciences Center, Portland, Ore. Accepted for publication in March 1977. 2 Present address: Department of Radiology, Northwest Hospital, 1551 North 120th, Seattle, Wash. 98133. shan
471
472
TIMOTHY G. LEE AND BILL H. WARREN
August 1977
Fig. 2. Sagittal scans in approximately the same locations at different times during the same examination. A. Fluid-filled stomach (5). B. Emptying of stomach (5) with filling of another fluid structure, probably duodenum (D). Fetal bladder (Fb).
Fig. 3. Sagittal scans during same examination. Fetal bladder (Fb). B. Change in caliber of bowel loops (B).
A. Fluid-filled bowel loops (B) in fetal abdomen.
the ovaries as well as the malrotated small bowel were extruded through the defect. The second stage repair was performed four days later, after the bowel contents had been gradually replaced into the abdomen. The intra-abdominal fluid-filled mass noted on ultrasound probably represented dilated bowel loops, but an explanation was not sought at surgery because of the precarious condition of the infant.
DISCUSSION
Fig. 4. Sagittal scan shows fetal bowel (8) floating in ascitic fluid (A), and liver (L) separated from lateral abdominal wall by fluid. in the umbilical area without a covering peritoneal membrane. Four hours later, a first stage gastroschisis repair using Silon and a feeding gastrostomy were performed. It was noted that part of the colon and
Antenatal demonstration by ultrasound of two abnormal fluid-filled spaces in the fetal abdomen was described by Loveday et al. (8). The significance of this finding was not fully appreciated until a postpartum radiograph (obtained because of abdominal distension) showed the typical findings of duodenal atresia. In our cases of jejunal atresia and gastroschisis, abnormal fetal bowel patterns were detected during obstetrical scanning. The importance of these findings was recognized because the normal antenatal fetal bowel pattern has been observed during routine scanning of other patients (Figs. 1-3). Fetal bowel, unlike that of the adult, is filled with fluid
Ultrasound
Fig. 5. Scans show dilated tubular fluid-filled bowel loops (B). Fetal bladder (Fb). A. Sagittal scan. B. Transverse scan. C. Abdominal radiograph taken immediately postpartum reveals multiple dilated loops of bowel. D. Barium enema demonstrates malrotated microcolon.
Fig. 6. A. Transverse scan shows fluid-filled bowel loops (B) outside of fetal abdomen surroundedby amniotic fluid. Note in addition fluid mass (M) inside abdomen. B. Sagittalscan also demonstratesbowel loops (B) outside of the fetal abdomen. C. Sagittal scan again shows fluid mass (M) inside the abdomen.
473
474
TIMOTHY
G.
LEE AND BILL
rather than gas, and therefore can be examined by ultrasound. The presence of unusual dilated tubular structures calls for an attempt to explain these findings by careful scanning of the fetal abdomen. Bowel obstruction should be considered. Diagnosis can also be based on abnormal location of bowel loops, as in our case of gastroschisis. Fluid-filled structures not resembling bowel may be of renal or pelvic origin; antenatal ultrasonography of these organs has been previously reported (6). Our experience shows that fetal bowel abnormalities can be diagnosedantenatally by careful observation of fetal bowel patterns. Timothy G. Lee, M.D. Department of Diagnostic Radiology University of Oregon Health Sciences Center 3181 S.W. Sam Jackson Park Road Portland, Ore. 97201
REFERENCES 1. Campbell S, Johnstone FD, Holt EM, et al: Anencephaly: early ultrasonic diagnosis and active management. Lancet 2: 1226-1227,9 Dec 1972
H.
WARREN
August 1977
2. Cunningham ME, Walls WJ: Ultrasound in the evaluation of anencephaly. Radiology 118:165-167, Jan 1976 3. Garrett WJ, GrunwaldG, Robinson DE: Prenatal diagnosis of fetal polycystic kidney by ultrasound. Aust New Zeal J Obstet Gynaec 10:7-9, Feb 1970 4. Hellman LM, Kobayashi M, Cromb E: Ultrasonic diagnosis of embryonic malformations. Am J Obstet GynecoI115:615-623, Mar 1973 5. Kossoff G, Garrett WJ, Radovanovich G: Grey scale echography in obstetrics and gynaecology. AustralasRadioI18:62-111, Mar 1974 6. Lee TG, Blake S: Prenatal fetal abdominal ultrasonography and diagnosis. Radiology 124:475-477, Aug 1977 7. Lee TG, Newton BW: Posteriorfossa cyst: prenataldiagnosis by ultrasound. J Clin Ultrasound 4:29-30, Feb 1976 8. LovedayBJ, Barr JA, Aitken J: The intra-uterinedemonstration of duodenal atresia by ultrasound. Br J Radiol 48: 1031-1 032, Dec 1975 9. Santos-Ramos R, Duenhoelter JH: Diagnosis of congenital fetal abnormalities by sonography. Obstet Gynecol 45:279-283, Mar 1975 10. Shaub M, Wilson R, Collea J: Fetal cystic lymphangioma (cystic hygroma): prepartum ultrasonic findings. Radiology 121: 449-450, Nov 1976 11. Valenti C. KassnerEG, Yermakov V, et al: Antenataldiagnosis of a fetal ovarian cyst. Am J Obstet Gynecol 123:217-219, Sep 1975
Bowel 1
Ultrasound
Timothy G. Lee, M.D., and Bill H. Warren, M.D.2 Although ultrasound evaluation of the adult gastrointestinal tract is largely impossible because of bowel gas, the fetal bowel is fluid-filled and therefore not subject to this limitation. In our experience, the fetal bowel pattern can be recognized and antenatal abnormalities detected. INDEX TERMS: (Fetus, amniotic sac, ultrasonography, 8[56].1298). Fetus, ultrasound • Intestines, ultrasound studies
Radiology 124:471-474, August 1977
A NTENATAL
DIAGNOSES by ultrasound include early embryonic malformations (4), central nervous system abnormalities (1, 2, 5, 7, 9), renal abnormalities (3, 6, 9), ovarian cysts (6, 11), and cystic lymphangioma (10). To our knowledge, only one case of an antenatal diagnosis of fetal bowel abnormality has been reported (8), although bowel involvement was not recognized until after birth. We have found that the fetal bowel pattern can be recognized antenatally, and the purpose of this paper is to show that differentiation of normal from abnormal bowel pattern is possible.
M
Fig. 1. Sagittal scan shows fluid-filled stomach (8) under the left hemidiaphragm.
METHOD
The following cases were encountered during routine obstetrical scanning of the maternal abdomen for biparietal diameter, placental localization, and fetal position, using a standard commercially available gray scale B-scan unit and 2.25 MHz transducer. Additional scans directed at the fetal abdomen were obtained when abnormal findings were noted.
and polyhydramnios. Fetal bowel was seen floating in ascitic fluid (Fig. 4). The fetal liver could also be seen separated by fluid from the lateral abdominal wall. CASE II. P.H., an 18-year-old gravida II, Para 1, was referred for follow-up ultrasound examination because of being large for dates. Ultrasound showed a 35-week fetus. Multiple dilated tubular fluid-filled structures in the fetal abdomen were noted and believed to be dilated bowel loops. Because these findings were persistent, bowel obstruction was suspected (Fig. 5, A and B). Amniocentesis showed a meconium-stained aspirate positive for anti-Kell antibodies. [These are minor blood subgroups and may cause fetal maternal blood incompatibility.] The ultrasound observations were confirmed immediately postpartum by an abdominal radtoqraph; which showed multiple dilated loops of bowel; a barium enema revealed a malrotated microcolon (Fig. 5, C and D). At surgery, jejunal atresia and a "Christmas tree" or "apple peel" type of deformity of the small bowel were discovered.
NORMAL EXAMINATIONS I. L.A., a 20-year-old gravida I, was referred for ultrasound examination because of uncertain dates. Ultrasound showed a 28.5-week fetus. A fluid-filled stomach was also seen (Fig. 1). II. D.W., a 17-year-old gravida I, was referred for ultrasound examination because of premature labor. Ultrasound showed a 29-week fetus. A changing fetal bowel pattern was noted, with emptying of the stomach and filling of another fluid structure, probably the duodenum (Fig. 2, A and B).
III. L.F., a 20-year-old gravida III, Para 2, was referred for ultrasound examination because of repeat Caesarean section. Ultrasound showed a 35-week fetus. Fluid-filled loops were seen. The pattern of these loops changed with time, characteristic of bowel (Fig. 3, A and B).
CASE III. D.F., a 19-year-old gravida I, had premature rupture of membranes. Ultrasound revealed a 34-week fetus. In addition, two fluid-filled tubular structures outside of the fetal abdomen were noted (Fig. 6, A and B), and the possibility of herniated bowel loops secondary to gastroschisis or omphalocele was suggested. A large, fluid-filled mass was also noted inside the fetal abdomen and the possibility of a bowel, renal, or pelvic origin of the mass was raised (Fig. 6, A and C). Two hours after rupture of membranes, a meconium-stained infant was delivered vaginally. Multiple bowel loops protruded through a defect
CASE REPORTS CASE I. K. F., a 17-year-old gravida I, was referred because of preeclampsia and suspected twins. Ultrasound showed a hydropic fetus
1 From the Department of Diagnostic Radiology, University of Oregon Health Sciences Center, Portland, Ore. Accepted for publication in March 1977. 2 Present address: Department of Radiology, Northwest Hospital, 1551 North 120th, Seattle, Wash. 98133. shan
471
472
TIMOTHY G. LEE AND BILL H. WARREN
August 1977
Fig. 2. Sagittal scans in approximately the same locations at different times during the same examination. A. Fluid-filled stomach (5). B. Emptying of stomach (5) with filling of another fluid structure, probably duodenum (D). Fetal bladder (Fb).
Fig. 3. Sagittal scans during same examination. Fetal bladder (Fb). B. Change in caliber of bowel loops (B).
A. Fluid-filled bowel loops (B) in fetal abdomen.
the ovaries as well as the malrotated small bowel were extruded through the defect. The second stage repair was performed four days later, after the bowel contents had been gradually replaced into the abdomen. The intra-abdominal fluid-filled mass noted on ultrasound probably represented dilated bowel loops, but an explanation was not sought at surgery because of the precarious condition of the infant.
DISCUSSION
Fig. 4. Sagittal scan shows fetal bowel (8) floating in ascitic fluid (A), and liver (L) separated from lateral abdominal wall by fluid. in the umbilical area without a covering peritoneal membrane. Four hours later, a first stage gastroschisis repair using Silon and a feeding gastrostomy were performed. It was noted that part of the colon and
Antenatal demonstration by ultrasound of two abnormal fluid-filled spaces in the fetal abdomen was described by Loveday et al. (8). The significance of this finding was not fully appreciated until a postpartum radiograph (obtained because of abdominal distension) showed the typical findings of duodenal atresia. In our cases of jejunal atresia and gastroschisis, abnormal fetal bowel patterns were detected during obstetrical scanning. The importance of these findings was recognized because the normal antenatal fetal bowel pattern has been observed during routine scanning of other patients (Figs. 1-3). Fetal bowel, unlike that of the adult, is filled with fluid
Ultrasound
Fig. 5. Scans show dilated tubular fluid-filled bowel loops (B). Fetal bladder (Fb). A. Sagittal scan. B. Transverse scan. C. Abdominal radiograph taken immediately postpartum reveals multiple dilated loops of bowel. D. Barium enema demonstrates malrotated microcolon.
Fig. 6. A. Transverse scan shows fluid-filled bowel loops (B) outside of fetal abdomen surroundedby amniotic fluid. Note in addition fluid mass (M) inside abdomen. B. Sagittalscan also demonstratesbowel loops (B) outside of the fetal abdomen. C. Sagittal scan again shows fluid mass (M) inside the abdomen.
473
474
TIMOTHY
G.
LEE AND BILL
rather than gas, and therefore can be examined by ultrasound. The presence of unusual dilated tubular structures calls for an attempt to explain these findings by careful scanning of the fetal abdomen. Bowel obstruction should be considered. Diagnosis can also be based on abnormal location of bowel loops, as in our case of gastroschisis. Fluid-filled structures not resembling bowel may be of renal or pelvic origin; antenatal ultrasonography of these organs has been previously reported (6). Our experience shows that fetal bowel abnormalities can be diagnosedantenatally by careful observation of fetal bowel patterns. Timothy G. Lee, M.D. Department of Diagnostic Radiology University of Oregon Health Sciences Center 3181 S.W. Sam Jackson Park Road Portland, Ore. 97201
REFERENCES 1. Campbell S, Johnstone FD, Holt EM, et al: Anencephaly: early ultrasonic diagnosis and active management. Lancet 2: 1226-1227,9 Dec 1972
H.
WARREN
August 1977
2. Cunningham ME, Walls WJ: Ultrasound in the evaluation of anencephaly. Radiology 118:165-167, Jan 1976 3. Garrett WJ, GrunwaldG, Robinson DE: Prenatal diagnosis of fetal polycystic kidney by ultrasound. Aust New Zeal J Obstet Gynaec 10:7-9, Feb 1970 4. Hellman LM, Kobayashi M, Cromb E: Ultrasonic diagnosis of embryonic malformations. Am J Obstet GynecoI115:615-623, Mar 1973 5. Kossoff G, Garrett WJ, Radovanovich G: Grey scale echography in obstetrics and gynaecology. AustralasRadioI18:62-111, Mar 1974 6. Lee TG, Blake S: Prenatal fetal abdominal ultrasonography and diagnosis. Radiology 124:475-477, Aug 1977 7. Lee TG, Newton BW: Posteriorfossa cyst: prenataldiagnosis by ultrasound. J Clin Ultrasound 4:29-30, Feb 1976 8. LovedayBJ, Barr JA, Aitken J: The intra-uterinedemonstration of duodenal atresia by ultrasound. Br J Radiol 48: 1031-1 032, Dec 1975 9. Santos-Ramos R, Duenhoelter JH: Diagnosis of congenital fetal abnormalities by sonography. Obstet Gynecol 45:279-283, Mar 1975 10. Shaub M, Wilson R, Collea J: Fetal cystic lymphangioma (cystic hygroma): prepartum ultrasonic findings. Radiology 121: 449-450, Nov 1976 11. Valenti C. KassnerEG, Yermakov V, et al: Antenataldiagnosis of a fetal ovarian cyst. Am J Obstet Gynecol 123:217-219, Sep 1975
