Table of contents

 

OBSTRUCTIVE UROPATHY

In brief
Hydronephrosis or renal dilatation is the most common fœtal abnormality detected during prenatal ultrasound evaluation.  In many cases this is mild and can be considered a variant of normal. In some instances this represents a significant obstruction to urine flow in both kidneys. Such affected fœtuses are at risk for the development of kidney damage in the form of renal dysplasia and underdevelopment of the lungs or pulmonary hypoplasia.  Both conditions can significantly threaten postnatal survival.  In properly selected cases relieving the obstruction can restore both urine flow and amniotic fluid levels.  This allows further lung and kidney development to proceed in a more favorable environment for the remainder of fœtal development. 

What happens next?
When a family is referred to the fœtal Diagnosis and Treatment Group for fœtal urinary obstruction, the coordinator will arrange for a detailed ultrasound and possibly other tests. A meeting will be arranged with one of the teams's pediatric urologist who will discuss the prognosis and treatment options. In most cases the condition will simply be followed with serial ultrasounds during the rest of the pregnancy and treatment (if required) can be done after birth. Prenatal intervention for fœtal urinary tract obstruction should be reserved for those fœtuses with impaired but not irreversibly compromised renal function.  The most accurate index of fœtal renal function is serial sampling of urinary electrolytes and protein.  This is performed under ultrasound guidance over a course of 3-4 consecutive days.  Serial aspiration provides a more accurate reflection of renal function as sequential bladder drainage may reveal an improving trend in initially borderline or poor electrolyte parameters. All fœtuses should additionally undergo chromosomal analysis as well as a careful evaluation for other significant anomalies. 

Treatment Options
Relief of fœtal urinary tract obstruction is reserved for select patients with severe bilateral hydronephrosis.  The urinary electrolytes must be favorable and there should be a trend towards decreasing or minimal amniotic fluid levels.  Additionally, the fœtus must have a normal chromosomal analysis and have no other associated anomalies of significance.  Options for intervention include vesicoamniotic shunting and open or fœtoscopic surgery.   Vesicoamniotic shunting involves the percutaneous placement of a stent communicating between the fœtal bladder and the amniotic cavity.  Open surgery can be performed to create a window between the fœtal bladder and the amniotic cavity that allows for the free drainage of urine.  Fœtoscopic surgery although still unproven has been used to place urethral stents, create a vesicostomy and to treat the obstruction primarily.

 

Some of our publications on this topic

González, R., De Filippo, R., Jednak, R., Barthold, J.S. Urethral atresia. Long term outcome in six children that survived the neonatal period. J. Urol. 165: 2241-2244, 2001.

G. Capolicchio, GA McLorie, W. Farhat, D. Bagli, P. Merguerian, AE Khoury. A population based analysis of continence outcomes in bladder exstrophy. J Urology 165:2418-2421, June 2001.

Sibai H, Pippi Salle JL, Houle AM, Lambert R : Hydronephrosis with Diffuse or Segmental Cortical Thining : Impact on Renal Function. J. Urol. 165 :2293-2295, June 2001.

D. Herz, G. Capolicchio, A. Hafez, D.Bagli, GA. McLorie, AE Khoury. Treatment of vesicoureteric reflux with submucosal Macroplastique: first North American report. J Urol 2001 Nov;166(5):1880-6.

Farhat W, McLorie G, Geary D, Capolicchio G, Bagli D, Merguerian P, Khoury A. The natural history of neonatal vesicoureteral reflux associated with antenatal hydronephrosis. J Urol. 2000 Sep;164(3 Pt 2):1057-60.

W. Farhat, G. McLorie, G. Capolicchio, A. Khoury, D. Bagli, P.A. Merguerian. Outcomes of primary valve ablation versus urinary tract diversion in patients with posterior urethral valves. Urology, 56(4): 653-657, 2000 Oct.

Jednak, R., J. V. Kryger, J. S. Barthold, and González, R. A simplified technique of upper pole heminephrectomy for duplex kidney. J. Urol. 164: 1326-1328, 2000.

Capolicchio G, Jednak R, Dinh L, Pippi Salle JL, Brzezinski A and Houle A: Supranormal renographic differential renal function in congenital hydronephrosis: fact not artifact. J. Urol., 161(4):1290-1294, 1999.

Capolicchio G, Wong C, Jednak R, Leonard MP, Brzezinski A, Pippi Salle JL: Prenatal diagnosis of hydronephrosis: impact on renal function and its recovery after pyeloplasty. J. Urol., 162(3) :1029-1032, 1999.

Pippi Salle JL, Chan PTK: One stage bladder exstrophy and epispadias repair in newborn male. Can. J. Urol., 6(2):757-761, 1999.

Pippi Salle JL : Management of bladder exstrophy in the male newborn. Revista Da Sociedade Iberoamericana de Urologia Pediatrica, 1 (1) :40-41, August 1999.

Barthold, J.S., Kryger, J.V., Derusha, A.M., Duel, B.P., Jednak, R., and Skafar, D.F. Effects of an environmental endocrine disruptor on fœtal development, estrogen receptor and epidermal growth factor receptor expression in the porcine male genital tract. J. Urol. 162: 864-871, 1999.

McLorie GA, Pippi Salle JL, Merguerian P, Bagli JD, Khoury AE: Simultaneous repair of bladder exstrophy and epispadias in male infants. J. Urol., 159(5):157, May 1998.

Homayoon K, Pippi Salle JL, Agarwal SK, Bagli DJ, McLorie GA, Gilday DL, Khoury AE: Relative accuracy of renal scan in estimation of renal function during partial ureteral obstruction. Can J. Urol., 5(4), 611-619, October 1998.

Capolicchio G, Homsy YL, Houle A-M, Brzezinski A, Stein L, Elhilali MM. Long-term results of percutaneous endopyelotomy in the treatment of children with failed open pyeloplasty. J. Urol., 158: 1534, 1997.

Adzick, M.R. Harrison, A.W. Flake, J.M. Laberge, R.L. Villa: Development of a fœtal Renal Function Test Using Endogenous Creatinine Clearance. J Pediatr Surg 20:602-607, l985.


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OMPHALOCELE

In brief
An omphalocele is an abdominal wall defect whereby the intestines and/or the liver herniate outside the abdomen at the base of the umbilicus.  The organs are covered by membranes, and this characteristic enables the ultrasonographer to differentiate it from gastroschisis, another type of defect.

The size of an omphalocele may vary widely.  Giant omphaloceles are those containing the liver or measuring more than 5 centimeters in diameter.

Omphaloceles are frequently associated with other malformations such as cardiac or genitourinary.  They may also be associated with chromosomal anomalies such as Trisomy 13, 18 or 21.  There are also some associations with syndromes like Beckwith-Wideman and pentalogy of Cantrell.

Ultimately the prognosis depends on both the size of the defect and the presence of other anomalies.

What happens next?
Once a patient is referred to the McGill fœtal Diagnosis and Treatment Group because of possible omphalocele, the evaluation will include a detailed ultrasound to confirm the diagnosis and mostly differentiate it from gastroschisis, another abdominal wall defect with different implications.  Because of the high likelihood of associated anomalies, we recommend undergoing an amniocentesis and a fœtal echocardiogram.  Depending on those results, and following appropriate counseling, some families may choose elective termination of pregnancy.

When pregnancy is continued, a meeting is arranged with one of the team’s pediatric surgeons to discuss the diagnosis as well as the method and location of delivery.  A meeting with a neonatal nurse specialist is also arranged. We usually recommend delivery in a tertiary care center, close to the Children’s Hospital. For omphaloceles less than 5 cm in diameter, delivery may proceed vaginally.  For defects more than 5 cm or those containing liver, a cesarean section is indicated to prevent trauma during delivery.

Treatment Options
At birth, the exposed intestines will be carefully wrapped to prevent heat loss and dehydration and the newborn baby will be transferred immediately to the Children’s Hospital.  One option is to bring the baby to the operating room soon after birth and attempt to return all the intestines inside the abdomen.  This is called a one-stage or primary repair.  In some cases, this is not possible since the abdominal cavity is “too small” relative to the amount of intestines that need to be placed inside.  In these cases, we construct a “silo” that we sew to the abdominal wall.  The excess bowel is left in the silo and each day a little bit is pushed inside until the silo can be removed.  This is called a staged repair.  In some cases where it is preferable not to bring the newborn infant to the operating room soon after birth, the membranes covering the intestines can be used as a silo and rolled like a toothpaste tube, slowing pushing its content into the abdomen.  Definitive surgery follows.

Some of our publications on this topic

A.R. Hong, D.L. Sigalet, D.P. Croitoru, F.M. Guttman, J-M. Laberge: Sequential Sac Ligation for Giant Omphalocele. J Pediatr Surg 29:413-415, 1994. 

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GASTROSCHISIS

In brief
Gastroschisis is an abdominal wall defect whereby there is an opening, usually to the right of the umbilicus, through which the intestines end up outside the abdominal cavity.  There is no covering of the intestines, and this characteristic enables the ultrasonographers to make the prenatal diagnosis.

The incidence of gastroschisis is approximately 1:5000 and it is slightly more common in fœtuses of young mothers.  Unlike other abdominal wall defects, there is no increased risk of chromosomal anomalies.  There is a risk of concomitant atresia of the intestine (a type of obstruction) of about 10%.  Other , malformations are unusual.

With conventional treatment after birth, a successful outcome can be expected in over 90% of affected infants.  The most frequently encountered difficulty is poor bowel function, thought to result from prolonged exposure to amniotic fluid.

What happens next?
Once a patient is referred to the McGill fœtal Diagnosis and Treatment Group because of possible gastroschisis, the evaluation will include a detailed ultrasound to confirm the diagnosis and mostly differentiate it from Omphalocele, another abdominal wall defect with different implications.

The family will then meet with one of the team’s pediatric surgeons to discuss the diagnosis as well as the method and location of delivery.  A meeting with a neonatal nurse specialist is also arranged. We usually recommend delivery in a tertiary care center, close to the Children’s Hospital.  Although recommended by some doctors, we do not advocate routine cesarean section for gastroschisis as the benefits are unproven.  However, a cesarean may become necessary for obstetrical reasons. 

During the third trimester, we arrange frequent ultrasound examinations to monitor for the development of certain complications such as poor growth of the fœtus, bowel dilatation etc. which could prompt earlier delivery in some cases.

Treatment Options
At birth, the exposed intestines will be carefully wrapped to prevent heat loss and dehydration and the newborn baby will be transferred immediately to the Children’s Hospital.  One option is to bring the baby to the operating room soon after birth and attempt to return all the intestines inside the abdomen.  This is called a one-stage or primary repair.  In some cases, this is not possible since the abdominal cavity is “too small” relative to the amount of intestines that need to be placed inside.  In these cases, we construct a “silo” that we sew to the abdominal wall.  The excess bowel is left in the silo and each day a little bit is pushed inside until the silo can be removed.  This is called a staged repair.  More recently, another option is the placement of a “spring-loaded silo” that can be placed at the bedside without general anesthesia.  The definitive closure in the operating room takes place a few days later.

Some of our publications on this topic

Laberge J-M, Levard G. “The fate of undescended testes in patients with gastroschisis.”  Eur J Pediatr Surg. 7 163-165, 1997.

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SACROCOCCYGEAL TERATOMA

In brief
Sacrococcygeal teratoma is a rare tumor originating from the coccyx that affects approximately 1 : 40 000 newborns.  At birth, it is almost always benign (not cancerous).  It can usually be completely removed with a low risk of recurrence and a low risk of fecal incontinence.  Moreover, it is usually an isolated malformation. When this condition is diagnosed prenatally, the fœtus is monitored carefully for the development of placentomegaly (abnormally large placenta) and hydrops (generalized swelling). This implies that the mass is too large or requires too much of the fœtus’ blood flow  (phenomenon called vascular steal) which in turn causes the fœtus to develop heart failure.  That sequence of events often ends with in utero fœtal death.  Whenever a fœtus develops hydrops, there is an associated risk that the mother develops what is called “maternal mirror syndrome”, where the mother’s condition mirrors that of the sick fœtus.

What happens next?
When a patient is referred to the McGill Diagnosis and Treatment Group with a possible diagnosis of sacrococcygeal teratoma, a detailed ultrasound is performed to obtain as much information as possible about the mass. A fœtal echocardiogram is also recommended to assess cardiac function. Details of interest are whether the mass is solid, cystic or mixed and the degree of intraabdominal component.  The family will then be offered a meeting with one of the team’s pediatric surgeons to discuss the implications of having a SCT. The patient will then be monitored very carefully for the development of placentomegaly and/or fœtal hydrops.  If these conditions develop, premature delivery or fœtal surgery will be discussed as otherwise a fatal outcome is almost certain.  When the teratoma measures more than 5 cm in diameter, we will usually recommend delivery by cesarean section to avoid the risk of tumor rupture during vaginal delivery. 

Treatment options
As long as the fœtus is doing well in utero, resection of the teratoma soon after birth remains the treatment of choice and as mentioned above, the results can be expected to be excellent.  Small teratomas (less than 5 cm) are delivered vaginally whereas larger ones are best delivered by cesarean section.  Another scenario sometimes seen is in case of a large cystic teratoma.  We have had some patients in whom aspirating the cyst just before delivery allowed the patient to deliver vaginally and thereby avoid a cesarean. If placentomegaly / hydrops develop toward the end of gestation and the fœtus is mature enough, an emergency cesarean section will then be performed. When the fœtus is too young to be expected to survive outside the uterus, then fœtal surgery is the only option to try avoiding a fatal outcome.  In these cases, the uterus is opened, the mass (all or sometimes part of it) is removed, and the fœtus is returned inside the uterus and the pregnancy is allowed to continue for as long as possible. There is ongoing research to find ways to eliminate the tumor without subjecting the mother to such an operation.  

Some of our publications on this topic

Laberge J-M, Nguyen L T, Shaw K S: Teratomas, Dermoids, and other Soft Tissue Tumors, In PEDIATRIC SURGERY 3rd edition, pp. 905-926.  Keith W. Ashcraft, editor.   Chapter 68.  W.B. Saunders Company, 2000.

Kay S, Khalifé S, Laberge J-M Shaw K S, Morin L, Flageole H:   Prenatal percutaneous needle drainage of cystic sacrococcygeal teratomas.  J Pediatr Surg  34: 1148-1151, 1999.

A.W. Flake, M.R. Harrison, N.S. Adzick, J.M. Laberge, S.L. Warsof: fœtal Sacrococcygeal Teratoma. J Pediatr Surg 21: 563-566,  l986.

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CONGENITAL CYSTIC ADENOMATOID LUNG MALFORMATION

In brief
Congenital cystic adenomatoid lung malformation (CCAM) is a lung malformation that is suspected prenatally when a thoracic mass is detected on prenatal ultrasound. It can appear to be macrocystic or microcystic and is differentiated from sequestrations (another cause of thoracic mass) by the aberrant blood supply of the latter.  CCAM are rarely associated with chromosomal anomalies but may be associated with other structural anomalies such as cardiac.  Other causes of a thoracic mass, such as congenital diaphragmatic hernia (CDH) also have to be considered.

The prognosis of CCAM depends primarily on its evolution in utero. Depending on its size and rate of growth, CCAM may prevent adequate development of the remainder of the lungs, and impair normal heart function.  In the most severe cases, the fœtus may become hydropic.  fœtal hydrops describes the condition when fluid accumulates under the fœtus’ skin and in body cavities like the abdomen or the chest.  The finding of hydrops carries a very grim prognosis for the fœtus.  If the fœtus survives until birth, the newborn may have difficulty breathing or be asymptomatic depending to which extent the lungs have been affected

We recently reviewed the Canadian experience with CCAM and found that 56% of the lesions regressed somewhat in utero.  That information was important to appreciate as a period of observation is definitely warranted when the diagnosis is first made.

What happens next?
When a patient is suspected of carrying a fœtus with a CCAM, the family is referred to the fœtal Diagnosis and Treatment Group.  The coordinator will arrange a detailed ultrasound, at which time an amniocentesis may be recommended, and possibly other tests.  A fœtal echocardiogram is also usually performed to rule out associated congenital heart malformations.

The family will then meet one of the team’s pediatric surgeons who will go over the diagnosis in details and explain the treatment options depending on the prognosis at the time.

Treatment options
When a CCAM is first diagnosed, unless the fœtus is already hydropic, we will normally recommend a period of observation of 1-2 weeks.  We know that 56% of the lesions will regress in utero and in those cases, and the cases where the lesion is stable, no treatment is required before birth and the survival of the newborn is around 90%.  At birth, the newborn is operated for resection of the CCAM if symptomatic.  In many babies who are asymptomatic, resection is nonetheless required but can be performed  at a few months of age.  When the lesion progresses in utero and hydrops develops, the prognosis is dismal for the fœtus and fœtal intervention offers the only hope of a good outcome.  In cases where the lesion has large cysts (macrocystic), aspiration of the cyst and possibly  placement of a thoraco-amniotic shunt (a small catheter to empty the cyst) can be done.  In cases where the lesion is microcystic , fœtal surgery and resection of the mass has been performed successfully in several patients.

Some of our publications on this topic

J.M. Laberge, H. Flageole, D. Pugash, S. Khalife, G. Blair, D. Filiatrault, P. Russo, G. Lees, R.D. Wilson: Outcome of the Prenatally Diagnosed Congenital Cystic Adenomatoid Lung Malformation: A Canadian Experience. fœtal Diagn Ther 16:178-186, 2001.

Laberge J-M, Filiatrault D, Khalife S, Flageole H, Russo P, Pugash D, Blair G: Diagnostic anténatal des malformations adénomatoïdes du poumon: L’expérience canadienne. Médecine fœtale et Echographie en Gynécologie 28: 11-17, 1996.

I.R. Neilson, P. Russo, J-M. Laberge, D. Filiatrault, L.T. Nguyen, P.P. Collin, F.M. Guttman: Congenital Adenomatoid Malformation of the Lung: Current Management and Prognosis J Pediatr Surg 26: 975-981, 1991.

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GIANT NECK MASSES

In brief
Some neck masses, most frequently lymphangiomas and teratomas, can grow to such sizes during gestation that they compress and obstruct the esophagus and/or trachea.  If the esophagus is obstructed, the fœtus is unable to swallow amniotic fluid and polyhydramnios (excess amniotic fluid) develops, possibly causing preterm labor. If this condition is either undetected or not addressed prior to delivery, the fœtus may develop respiratory distress immediately at birth.  Because the normal anatomy is distorted by the mass, it may be very difficult, sometimes impossible to pass a breathing tube down the airway.  If it takes too long, the baby may suffer irreversible brain damage or even die if no airway is obtained.  This complication is particularly tragic since the neck mass is the only anomaly and the infant could have a normal life after resection of the mass.  Fortunately, when neck masses obstructing the fœtal airway are detected prenatally, it allows for a planned strategy where the airway is secured before the circulation from the umbilical cord is interrupted.  Such a strategy is called the EXIT (ex-utero intrapartum treatment) procedure.

What happens next?
When a family is referred to the McGill  fœtal Diagnosis and Treatment Group for a neck mass, a detailed ultrasound will be done focusing on the relationships of the mass to the adjacent neck structures.  Another imaging modality that is sometimes useful in these cases if fœtal magnetic resonance.  In addition, an amniocentesis is recommended to search for genetic anomalies as well as a fœtal echocardiogram to look for congenital heart malformations.  Once the evaluation is completed, the family will be offered a meeting with one of the team’s pediatric surgeons to discuss treatment options.

Treatment options
If the neck mass is not found to compromise the airway, the patient is followed closely with frequent ultrasound.  In cases where only the esophagus is obstructed and polyhydramnios is the problem, amniotic fluid may be removed on one or more occasions to decrease the risk of preterm delivery.  When the mass contains large cysts, those may be aspirated periodically to minimize the mass effect.  When the mass continues to grow and obstructs the airway, the EXIT (ex-utero intrapartum treatment) procedure is the treatment of choice.  This procedure aims to secure the baby’s airway while the circulation from the placenta is maintained.  This is accomplished by high-level coordination between surgeon and anesthetist.  The uterus is opened as in a cesarean section with the difference that the anesthetist gives medications that keep it relaxed.  The upper body of the fœtus can be brought out, the airway secured by whatever technique is necessary, during which time the fœtus still receives its oxygen from the umbilical cord.  Once the airway is secured, the cord can be cut and the baby delivered. At that time another medication is started to make the uterus contract as in a normal cesarean section.

We recently successfully performed an EXIT procedure at our center.  It was the first time in Quebec and the patient’s mass one of the largest ever described with a good outcome.  The EXIT procedure is not without risks for the mother, but with a good coordination between all members involved, those can be kept well within the accepted range for traditional cesarean section.

Some of our publications on this topic

Laberge J-M, Nguyen L T, Shaw K S: Teratomas, Dermoids, and other Soft Tissue Tumors, In PEDIATRIC SURGERY 3rd edition, pp. 905-926.  Keith W. Ashcraft, editor.   Chapter 68.  W.B. Saunders Company, 2000.

Alqahtani A, Nguyen L T, Flageole H, Shaw K, Laberge J-M,:  25 years experience with lymphangiomas in children.  J Pediatr Surg 34: 1164-1168, 1999.

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CONGENITAL DIAPHRAGMATIC HERNIA

In brief
Congenital diaphragmatic hernia (CDH) is a malformation whereby the liver and intestines are allowed to herniate into the chest through a defect in the diaphragm, the muscle that normally separates the abdominal and thoracic cavities.  It is quite a common malformation, occurring 1:2500 live births.  The presence of abdominal contents in the chest prevents the lungs from developing normally leading to pulmonary hypoplasia (lungs smaller than normal).   It is the pulmonary hypoplasia that puts the baby’s survival at risk.  The degree of pulmonary hypoplasia, and indirectly the prognosis, can be estimated by various factors detailed below.  The reported survival for infants affected with CDH varies widely, from about 50 – 80%, due to many factors.

What happens next?
When a CDH is suspected on prenatal ultrasound, the family is referred to the fœtal Diagnosis and Treatment Group.  A detailed ultrasound and MRI will be done, plus an amniocentesis to detect any possible associated chromosomal anomaly.  A fœtal echocardiogram is also routinely done to screen for cardiac malformations.  The family is then directed to one of the team’s pediatric surgeons who will discuss with them the prognosis and different treatment options possible.  A meeting with a neonatal nurse specialist is also arranged.

Treatment options

The treatment options will be different whether one is dealing with a “good” or “poor” prognosis CDH.  Factors predicting a poor prognosis are:          

 -diagnosis < 25 weeks and
-liver in the chest and
-lung-to-head ratio < 1.0

Additionally, the presence of associated chromosomal anomalies and/or heart malformations carries a grim prognosis.

Fœtuses thought to have a good prognosis require no prenatal intervention but are advised to deliver at a center offering state of the art neonatal treatment including nitric oxide, high-frequency ventilation and ECMO (Extracorporeal membrane oxygenation).

The fœtuses who have no associated anomalies and are thought to have a poor prognosis based on the above-listed criteria may be candidates for fœtal intervention in the form of tracheal obstruction up to 26 weeks of gestation.  Occluding the fœtal trachea creates increased pressure in the developing lungs and that has been shown to stimulate the lungs to grow much faster, and to gradually push back the herniated viscera in the abdomen.  Our team’s research interests has focused on that treatment for the last several years.  We have developed a minimally invasive method of tracheal occlusion that is now successfully used in patients in U.S. Centers such as University of California at San Francisco. At last we can offer renewed hope to these families.

Some of our publications on this topic

Bratu I*, Flageole H, Laberge JM, Chen MF, Piedboeuf B: Pulmonary structural maturation and pulmonary artery remodeling after reversible fœtal ovine tracheal occlusion in diaphragmatic hernia.  J Pediatr Surg 36:739-744, 2001.

Bratu I*, Flageole H, Laberge JM, Piedboeuf B, Whitsett LJ, Possmayer F: Surfactant levels after reversible fœtal tracheal occlusion and prenatal steroids in experimental diaphragmatic hernia.  J Pediatr Surg 2001;36:122-127.

J.A.M. Deprest, V.A. Evrard, E.K. Verberken, A.J. Perales, P.R. Delaere, T.E. Lerut, H. Flageole: Tracheal side effects of endoscopic balloon tracheal occlusion in the fœtal lamb model.  Eur J Obstet Gynecol Reprod Biol 92:119-126; 2000.

Bratu I, Flageole, H, Laberge J-M, Kay S, Piedboeuf B:  “Growth and Structural Development after Reversible fœtal Tracheal Occlusion in Diaphragmatic Hernia.”  Surgical Forum Vol L: 569-570, 1999.

VA Evrard, J.A. Deprest, T.E. Lerut , K. Vandenberghe, H. Flageole:  “Intra-uterine fœtal tracheal obstruction decreases amniotic fluid sodium and chloride concentration in the ovine model.” Ann Surg 226:753-758, 1997.

Flageole H, Evrard VA, Vandenberghe K, Lerut TE, Deprest JA: “Tracheoscopic Tracheal Occlusion in the ovine model: possible application in Congenital Diaphragmatic Hernia.” J Pediatr Surg 32(9):1328-31, 1997.

Piedboeuf B, Laberge J-M, Gamache M, Petrov P, Bélanger S, Chen M-F, Hashim E, Ghitulescu G, Possmayer F. “Deleterious Effect of Tracheal Obstruction on Type II Pneumocytes in the fœtal Sheep.”     Pediatric Research 41:4, 473-479, 1997.

The Effects of the Tracheal Occlusion and Release on Type II Pneumocytes in fœtal Lambs.”  Bin-Saddiq W, Piedboeuf B, Laberge J-M, Gamache M, Petrov P, Hashim E, Manika A, Chen M-F, Bélanger S, Piuze G.   J Pediatr Surg 32:6;834-838, 1997.

J-M. Laberge, D.L. Sigalet and F.M. Guttman. Congenital Diaphragmatic Hernia.   In HERNIA, 4th edition, L.M. Nyhus and R.E. Condon editors.  Chapter 43, p.555-566.  J.B. Lippincott, Philadelphia, 1995.

DL Sigalet, A Tierney, VR Adolph, T Perreault, N Finer, R Hallgren, J-M Laberge. “Timing of repair of congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation support.”   J Pediatr Surg 30:1183-1187, 1995.

E Hashim, J-M Laberge, M-F Chen, EW Quillen Jr. "Reversible tracheal obstruction in the fœtal sheep: Effects on  tracheal fluid pressure and lung growth.” J Pediatr Surg 30:1172-1177, 1995.

VR Adolph, H Flageole, T Perreault, A Johnston, LT Nguyen, S Youssef, FM Guttman, J-M Laberge. “Repair of congenital diaphragmatic hernia after weaning from extracorporeal membrane oxygenation."   J Pediatr Surg 30:349-352, 1995.

D.L. Sigalet, A.R. Hong, V. Adolph, J-M. Laberge, L.T. Nguyen, F.M. Guttman: Gastroesophageal reflux associated with large diaphragmatic hernias.  J Pediatr Surg 29:1262-1266, 1994.

U. de Luca, R. Cloutier, J-M Laberge, H. Prendt, D. Major, D. Edgell, P.E. Roy, S. Roberge, F.M. Guttman: Pulmonary Barotrauma in Congenital Diaphragmatic Hernia: Experimental Study in Lambs. J Pediatr Surg 22:  311-316,  l987.

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CONGENITAL HEART DISEASE

Fetal echocardiography is a very detailed ultrasound of the heart and its functions. It is generally supervised by a pediatric cardiologist. The obstetrician plays an essential role in the prenatal detection of cardiac malformations. However, a detailed evaluation of the fetal heart is difficult. The cardiac malformations detectable during the pregnancy are diverse and often complex. The pediatric cardiologist is better equipped to reach an accurate diagnosis and to explain the different options that can be offered to the family during the pregnancy or after the delivery. Fortunately, in most cases, the pediatric cardiologist will be able to reassure the family to the effect that their child's heart is really normal and will unlikely be cause for concerns.

WHY OFFER AN ECHOCARDIOGRAM ?

Your obstetrician, radiologist or genetic counselor will recommend an echocardiogram if:

1. An extracardiac anomaly is noted on the detailed obstetrical ultrasound. It is generally recommended to offer a detailed ultrasound if any anomaly is detected during a routine obstetrical ultrasound. In fact, it is not unusual for malformations affecting different body organs to be associated with one another. The detailed examination of the fetal heart is usually done under the supervision of a pediatric cardiologist.

2. An abnormal result from the amniocentesis or chorionic villous sampling. Chromosomal anomalies are frequently associated with multiple malformations. The formation of the heart is very complex, so it not surprising that this organ is often affected. Conversely, if a cardiac malformation is detected, it is generally recommended to do an amniocentesis to exclude a chromosomal anomaly.

3. A significant family history.The different factors affecting the inheritance of cardiac malformations have not been clearly defined to date. Science teaches us, however, that genetic factors play a significant role for certain families, and that the risk of carrying a child with a cardiac malformation will be greater for these families than for the population in general. Generally for cardiac malformation, it is only if a first-degree relative (the father, mother, brother or sister) of the fetus is affected that an increased risk can be appreciated. Certain genetic diseases associated with cardiac malformations have been identified and, for some of them, specific tests are available. It is likely that within a few years we will be able to identify and understand the genetic mechanism that controls the formation and the development of the heart, and therefore, be able to better identify families at risk.

4. A health problem with the mother. Certain health problems in the mother can increase the risk of cardiac malformation in a child. It is the case with diabetes that is not well controlled during the first trimester at the time when the heart takes form. If diabetes is well controlled or if the mother develops gestational diabetes, the risks do not appear to be very different from those of the population in general. Uncontrolled diabetes during the last trimester can cause a thickening of the walls of the heart muscle. Fortunately, that condition usually resolves on its own and is not cause for concern. Some obstetricians prefer to offer an echocardiogram towards the end of the pregnancy to identify affected fetuses and plan their postnatal follow-up.

5. A cardiac anomaly is suspected on the routine obstetrical ultrasound. The obstetrician or the radiologist looks at the heart during the routine obstetrical ultrasound. He usually makes sure that the heart has four chambers. On some occasions, he will also look at the great arteries coming out of the heart. If the obstetrician has not seen the heart very well, or the heart appears abnormal, the mother will be referred to a pediatric cardiologist for a detailed fetal echocardiographic examination.

6. Irregularities in the heart rhythm. The fetal heart beats faster than the heart of an adult. In fact, the heart rate varies generally between 120 and 180 beats per minute. The heart rate is controlled by specialized cells that also ensure normal conduction of the cardiac impulse from the top of the heart, the atria, to the bottom of the heart, the ventricles. This system must mature during the pregnancy and minor irregularities in the heart rhythm are quite common. The echocardiographic examination will generally be recommended if the fetal heart rate is too slow, too fast, or very irregular. Although most of these variations are normal or without real impact, some require treatment. It is important to identify them correctly.

7. Intrauterine growth retardation, fetal distress or swelling of the fetus (hydrops). When the fetus is not well, it is important to identify the nature of the problem in order to be able to offer treatment. The examination of the heart will allow the clinician to identify a heart problem if such is the case, to evaluate the cardiovascular well being of the fetus, and to identify cardiovascular risk factors that might modify the obstetrical treatment.

WHEN CAN THIS TEST BE OFFERED ?

Complete detailed examination of the fetal heart is possible from the 18th week of the pregnancy. It can be offered at all times thereafter. The fetal heart measures between 15 and 20 millimeters at 18 weeks of pregnancy. In some circumstances, this detailed examination will be offered before the 18th week but then the heart is quite small and a detailed examination may not be possible. If this is the case, a follow-up appointment will generally be offered later in the pregnancy.