In utero fetal muscle biopsy: a precious aid for the prenatal diagnosis of Duchenne muscular dystrophy.

Prenatal diagnosis for Duchenne muscular dystrophy can usually be performed using DNA analysis. This approach would be impossible when there is only one prior affected male and no identifiable gene deletion. Therefore, in utero fetal thigh muscle biopsy with direct examination of muscle by dystrophin analysis may provide the only means of prenatal diagnosis. We report such a case in which fetal muscle biopsy was able to exclude Duchenne muscular dystrophy. A detailed literature review of the topic is provided.     

Fetal muscle biopsy as a diagnostic tool in Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a relentless progressive disorder, leading to severe disability during childhood and death in adolescence or early adulthood. In most families, prenatal diagnosis is readily achieved by molecular detection of DNA deletions using chorionic villi or amniocytes, or by linkage analysis. In some cases, however, molecular methods fail to provide a definitive diagnosis and in such cases in utero fetal muscle biopsy may serve as a diagnostic option. We describe three families in whom fetal muscle biopsy was performed, focusing on the prenatal diagnostic dilemmas, the indications and timing for in utero fetal muscle biopsy, and the difficulties encountered.     

Prenatal diagnosis of congenital anomalies--present status and future problems

Technical advances continue to expand the number of genetic disorders that can be diagnosed in utero. The current methods for prenatal diagnosis are as follows: Amniocentesis, fetoscopy, fetal blood sampling, biopsy of fetal skin, and chorionic villus sampling (CVS). The method for growing fetal cells obtained by amniocentesis in short term culture and karyotyping has opened a new area to chromosomal anomalies. By using cultured amniotic fluid cells in larger numbers, it is also possible to diagnose many metabolic disorders. Fetoscopy has been developed which permits the perinatologist to enter the uterus and obtain tissue sample or to actually view the fetus. However, it is very difficult to visualize the fetus directly through fetoscope. Only specific parts of the fetus can be readily identified, but a total examination of surface anatomy is rarely possible. Now ultrasonography with improved resolution can clearly define many major anatomical abnormalities without apparent risk. And also, fetal blood sampling and skin biopsy have been successfully performed under ultrasound guidance rather than under direct fetoscopic visualization. Recently, the advent of fetal blood sampling has made it possible to diagnose genetic disorders which have hitherto been impossible to recognize in the fetus. The main applications are for the prenatal diagnosis of the fetal infection, coagulopathies, hemoglobinopathies, and muscular dystrophies. Several severe genodermatoses result in early death or are associated with significant morbidity. Some of these disorders can be diagnosed in utero with skin biopsies. Harlequin Ichthyosis is a typical case. A positive prenatal diagnosis of Harlequin Ichthyosis was reported.(ABSTRACT TRUNCATED AT 250 WORDS)     

In utero fetal hematopoietic stem cell transplantation

The fetus is the preferred candidate for transplantation for a number of reasons. First, the fetal period is the earliest time at which an identified disorder can potentially be treated. If a fetus is identified with a treatable disorder in utero, and if that disorder can affect fetal development, then treatment during fetal life is potentially beneficial. A second advantage of in utero fetal HSC transplantation is the immunotolerance of the fetus, making it both a favorable donor and a favorable recipient. Finding a histocompatible donor and minimizing GVH disease are major concerns in bone marrow HSC transplantation. Fetal immuno-tolerance may eliminate the need for the former and significantly reduce the incidence and severity of the latter. The first hematologic disorders for fetal HSC transplantation may be sickle cell disease and the thalassemias, as recent technologic developments allow diagnosis in the first trimester. However, the potential targets for in utero fetal HSC transplantation are numerous and include a variety of genetic disorders of lymphocyte, platelet, leukocyte, red cell, and enzyme function. Disadvantages of in utero fetal HSC transplantation exist. First, it is necessary to have identified the fetus as being at risk for a genetic disorder, before the prenatal diagnosis can be made. This happens in one of two ways--either a previous pregnancy resulted in an affected fetus, or the parents of the fetus have been identified as being carriers of the genetic disorder.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biochemical examination of fetal skin biopsy specimens obtained by fetoscopy: use of the method for analysis of keratins and filaggrin

This paper describes a method for biochemical analysis of proteins from fetal skin biopsy samples. The method has wide potential application for diagnosis of disorders with a known protein abnormality detectable by protein staining or a specific antibody. Analysis requires a single 1 mm biopsy, is rapid (2 days) and extremely sensitive. In the present study, fetal skin biopsies from normal fetuses and a fetus at risk for lamellar ichthyosis were obtained. The epidermis or hairs with attached follicular cells were dissected from the remaining skin. Proteins were extracted and separated by SDS-polyacrylamide gel electrophoresis. Proteins from duplicate gels were transferred to nitrocellulose and immunostained for the acidic and basic keratins and for the keratin filament associated protein, filaggrin, using monoclonal antibodies. All samples contained keratins typical of fetal epidermis at 20 weeks gestation. Presence of filaggrin is variable at this age and depends on the presence of keratinized cells of hair canals. No keratin abnormalities in the fetus at risk for lamellar ichthyosis were detected, however, in one presumably normal biopsy, an abnormally low proportion of the 67 kd keratin and the presence of follicular keratins were evident. These results demonstrate that biochemical analysis of fetal biopsies is possible, thus increasing the diagnostic potential of the fetal biopsy procedure for disorders in which a known protein or antigen is altered in utero.     

Status of prenatal diagnosis using direct interventions on the fetus

Prenatal diagnosis has developed into a large flourishing multidisciplinary branch of medicine. At present prenatal diagnosis is world-wide possible in the second trimester of pregnancy by analysis of both amniotic fluid obtained by amniocentesis or amniotic cell cultures. Ultrasound plays a central role in prenatal diagnosis, and has revolutionized obstetric practice. Without dealing with all aspects of prenatal diagnosis we have discussed the following invasive procedures, which give the prenatal diagnosis its forward thrust: fetal blood sampling including intravascular transfusion, fetal skin-, liver- and muscle biopsy, chorion biopsy, selective birth in twin pregnancies, and fetal therapy including fetal surgery. In utero surgery is in its earliest stages. Such simple procedures as decompression of the hydronephrotic kidney in obstructive uropathy, of the fetal lungs in pleural effusions caused by chylothorax, or of the hydrocephalic ventricle may be useful, but the possible success rate for such efforts remains still uncertain. The possibilities of first-trimester prenatal diagnosis especially by DNA-technology or direct chromosomal and biochemical analysis has stimulated the development of a multiplicity of methods for taking chorion biopsies. Compared with second trimester amniocentesis, the introduction of prenatal diagnosis by chorionic villi sampling would reduce the psychic trauma for patients waiting on results and allow earlier and safer termination of pregnancy.     

Fetal hematopoietic stem cell transplantation

In utero hematopoietic stem cell transplantation (IUHSCTx) is a promising approach for the treatment of a potentially large number of fetuses affected by congenital hematologic disorders. With technical and molecular advances in prenatal diagnosis, the majority of these diseases can now be diagnosed early in gestation, allowing consideration of prenatal treatment. In addition, technical advances in fetal imaging and intervention make it possible to perform the transplants with relatively minimal risk. It, therefore, stands to reason that there is increasing interest in performing in utero hematopoietic stem cell transplantation at many fetal treatment centers. Although the approach remains experimentally promising, expansion of clinical application will depend on improved understanding of the biological barriers to engraftment in the fetus as well as the development of effective clinical strategies based on the hematopoietic biology of individual disorders. This article presents the current status of this emerging therapeutic approach.     

Prenatal diagnosis of congenital nephrosis by in utero kidney biopsy

The diagnosis of congenital nephrosis is difficult during the antepartum period. The combination of an elevated amniotic fluid alpha-fetoprotein, a negative acetylcholinesterase, and a negative ultrasound examination is highly indicative of congenital nephrosis; however, these findings can also be associated with a normal gestation. This is the first report of pathologic confirmation of congenital nephrosis from an in utero fetal kidney biopsy.     

Duchenne and Becker muscular dystrophies: genetics, prenatal diagnosis, and future prospects

DMD and BMD are now understood at the genetic, biochemical, and molecular levels. At the genetic level, both disorders result from mutations of the X-linked gene encoding dystrophin. At the biochemical level, DMD results from the deficiency of a large protein called dystrophin, whereas BMD results when dystrophin is present, though abnormal in either amount or molecular structure. To date, thousands of patients have been analyzed for mutations of the dystrophin gene in peripheral blood DNA or alterations of the dystrophin protein in muscle tissue. The severity of the clinical phenotype of these patients has been compared with their dystrophin gene mutations and corresponding dystrophin protein alterations, revealing an unexpectedly high degree of correlation. Thus, information derived from the molecular analysis (DNA or protein) of a particular patient provides a "molecular diagnosis," which is highly predictive of the clinical course that patient can be expected to follow. Because molecular diagnoses are independent of the patient's age, they provide a prognosis for the large majority of muscular dystrophy patients even before clinical symptoms of their disease become apparent. Such prognostic molecular diagnoses have proven particularly valuable when the patient is an isolated case, with no family history for the disorder. Prenatal genetic diagnosis of DMD or BMD may involve use of Southern blot or PCR techniques to search for a deletion in the DNA of at-risk fetuses or more complicated family linkage studies using intragenic and flanking RFLPs. More recently, assay of dystrophin content in fetal skeletal or cardiac muscle from at-risk abortuses has been accomplished, allowing definitive discrimination of affected and normal fetuses in cases in which deletion analyses and family DNA studies were equivocal. In utero fetal skeletal muscle biopsy for dystrophin protein assay has actually been accomplished in at least one at-risk pregnancy in which family DNA studies were uninformative. Dystrophin was present in skeletal muscle from this 20-week-old male fetus, and the pregnancy continued, resulting in the term birth of a healthy male infant. The future holds exciting opportunities for neonatal screening and treatment of these devastating neuromuscular diseases.     

Prenatal diagnosis of carbamyl phosphate synthetase deficiency by fetal liver biopsy]

Carbamyl phosphate synthetase deficiency (CPSD) is one of the enzyme defects of the urea cycle and inherited as an autosomal recessive. A definitive enzymatic diagnosis of CPSD can be made by biochemical assay of liver biopsy material, but not of cultured fibroblasts. In pregnancy at risk for CPSD, prenatal diagnosis was attempted by fetal liver biopsy, performed at 22 weeks of gestation. CPS activity was present and a healthy baby was delivered at term. The technique employed for fetal liver biopsy is described together with an evaluation of its possible role in prenatal diagnosis.     

Impaired fetal growth: ultrasonic evaluation and clinical management

Although biparietal diameter has become the standard fetal dimension for dating purposes, it is accurate in the diagnosis of intrauterine growth retardation in only 50% of cases. Serial assessment of the abdominal circumference, on the other hand, may allow more accurate identification of impaired growth. The combined use of biparietal diameter and abdominal circumference in the estimation of fetal weight in utero directly addresses the basis of the diagnosis of impaired fetal growth. Ultrasonic observation of amniotic fluid volume, fetal muscle tone, and the texture of the placenta may also be valuable in the diagnosis of intrauterine growth retardation. Once a diagnosis of impaired fetal growth is made, the clinical management includes, possibly, treatment of maternal factors that may be contributing to the growth retardation and monitoring of fetal and maternal well being with delivery if serious deterioration of either mother or fetus is noted. Maximal safe retention in utero is the management goal, as long as some growth is noted and acute distress is not seen.     

Ultrasonic detection of fetal ascites associated with polyhydramnios

The combination of fetal ascites and polyhydramnios is an uncommon problem that can be detected in utero by sonography. A case is reported where the etiology was found to be generalized cytomegalovirus infection. The differential diagnosis, etiology and diagnostic procedures are discussed.A thorough sonographic study is essential in the diagnosis and evaluation of fetal ascites in utero.     

Early amniocentesis: accidents and incidents. Study of a series of 681 single pregnancies

The authors studied the outcome of 681 single pregnancies after amniocentesis. The advantage of this study is to determine the exact risk of this procedure, especially as far as spontaneous miscarriage is concerned. 82% of the taps are carried out between 17 and 18 weeks of amenorrhea. A maternal age over 38 years (56%) represent the essential indication. Questionable cases are presented are presented by cases of intrapartum and neonatal mortality (a case of hypotrophy with death in utero at 39 weeks; a case of per-partum death during a cesarean section). There are cases of fetal death in utero where the time between the tap and the diagnosis of fetal death exceeds 4 weeks and where there is no argument for an infectious etiology. Finally, there are several cases where the responsibility of the amniocentesis is unlikely. It often seems that the amniocentesis induces the spontaneous miscarriage of an already compromised pregnancy. Other incidents of amniocentesis are reviewed. A review of the literature has enabled us to draw certain conclusions. In light of their results and the data from the literature, the authors conclude that amniocentesis is not innocuous. At any rate, it is indicated for specific patients and these pregnancies must be considered as risk pregnancies.     

Doppler in fetal heart failure

Fetal echocardiography has progressed to be able to diagnose many forms of congenital heart disease (CHD) and to assess the prognosis of cardiac lesions based on their anatomy and presentation in utero. Fetal echocardiography is for pregnancies at risk of structural, functional, and rhythm-related fetal heart disease. Routine obstetrical ultrasound screening is critical in the prenatal detection of fetal heart disease/CHD. With or without CHD, fetal heart dysfunction defined as inadequate tissue perfusion may occur. Perinatal problems other than CHD can also be assessed, such as the effects of noncardiac malformations that affect hemodynamics, that is, twin-twin transfusion. Cardiac rhythm can affect cardiac function and outcome, and prenatal diagnosis can be lifesaving. A tool for the assessment of cardiac function is the Cardiovascular Profile Score that combines ultrasonic markers of fetal cardiovascular unwellness based on univariate parameters, which have been correlated with perinatal mortality. This "heart failure score" could potentially be used in much the same way as and in combination with the biophysical profile score. This study will present a summary of fetal Doppler and its place in the diagnosis and assessment of prognosis of fetal heart failure.     

Increased AFP as an indicator of ovarian carcinoma and fetal kidney carcinoma--case report

We examined a young primipara with increased alpha-fetoprotein (AFP) values and cystic tumefaction of the right ovary. Having in mind a mild decrease in ovarian artery resistance index (RI) and suspected findings of fetal kidney, this situation was delicate due to its double pathology which was later confirmed. Wilms' tumor is the most common urogenital tumor in childhood, and it is detectable in the prenatal period by ultrasound examination. In utero kidney biopsy confirms diagnosis and facilitates decisions concerning the course of pregnancy. Relative risk of intervention limits this diagnostic procedure for indicated cases.     

Requirements for fetal surgery: the diaphragmatic hernia model

Fetal surgery for congenital diaphragmatic hernia and other fetal conditions can only be considered if (1) the morbidity of antenatal intervention is acceptable, (2) the diagnosis of the condition can be made accurately, (3) the condition can be differentiated from other, non-surgical anomalies. In addition, (4) the natural evolution of the disease, if left untreated, should be predictable, and the condition should be lethal or severely debilitating, (5) there should not exist adequate postnatal treatment, and (6) the proposed in utero operation should be technically feasible. Open fetal surgery has proven too invasive to be justified for the treatment of diaphragmatic hernia, and progress in postnatal therapy (including ECMO) has dramatically improved the neonatal outcome in all but a severe subgroup of patients. Recently, advances in endoscopic fetal surgery (which appears to be less stressful for the fetus and the gravid uterus) and a new approach to accelerate fetal lung growth and maturation have renewed the feasibility of in utero intervention for diaphragmatic hernia.     

Successful management of fetal cervical teratoma using the EXIT procedure

Fetal cervical teratoma is a cause of polyhydramnios, premature labor, and newborn airway obstruction. Formation of a multispecialty team and use of the EXIT procedure is essential for survival of the neonate. Without a team, there is little hope for fetal survival; mortality will be 80-100%. Early diagnosis and planning are essential. Cervical teratomas can contribute to pulmonary insufficiency and chondromalacia because of a mass effect in utero and underdevelopment of the fetal lungs.     

Successful management of fetal cervical teratoma using the EXIT procedure

Fetal cervical teratoma is a cause of polyhydramnios, premature labor, and newborn airway obstruction. Formation of a multispecialty team and use of the EXIT procedure is essential for survival of the neonate. Without a team, there is little hope for fetal survival; mortality will be 80–100%. Early diagnosis and planning are essential. Cervical teratomas can contribute to pulmonary insufficiency and chondromalacia because of a mass effect in utero and underdevelopment of the fetal lungs.     

Diagnosis and prenatal diagnosis of epidermolysis bullosa herpetiformis (Dowling-Meara) in a mother, two affected children, and an affected fetus.

In utero skin biopsy was performed on a fetus at risk of an uncertain form of epidermolysis bullosa (EB). The mother had produced two affected offspring diagnosed variously as having junctional or dystrophic EB. The two offspring and the fetus were products of different fathers. The mother claimed to have no disease and on clinical examination was without blisters. Examination of the fetal skin biopsy by light and electron microscopy revealed separation of the epidermal sheet from the majority of the biopsy sample, although occasional remnants of basal cells remained associated with the basement membrane. Aggregations of keratin filaments were observed within basal cells of the detached epidermis and in the attached basal cell remnants. The diagnosis was thus suggested to be epidermolysis bullosa Dowling-Meara. Re-review of the clinical and laboratory data from the affected infants revealed a clinical and histological pattern consistent with this diagnosis. Further discussion with the mother revealed that her skin had blistered as a child and that she presently had hyperkeratotic palms and soles. This history is consistent with the autosomal dominantly inherited epidermolysis bullosa herpetiformis (Dowling-Meara). This is the first reported prenatal diagnosis of EB Dowling-Meara. The morphological criteria of intraepidermal blistering and clumped keratin filaments within basal and immediately suprabasal cells characteristic of an affected individual postnatally also identified an affected fetus. There is, however, insufficient experience to be certain that these findings will hold from region to region in the body or among all affected fetuses, and thus prenatal diagnosis on a morphological basis should still be made with caution.     

Prenatal diagnosis of carbamoyl-phosphate synthetase deficiency by fetal liver biopsy

In a pregnancy at risk for carbamoyl-phosphate synthetase (CPS) deficiency, prenatal diagnosis was attempted by fetal liver biopsy, performed at 18 weeks of gestation. CPS activity was absent and the diagnosis was confirmed after termination of the pregnancy. The technique employed for fetal liver biopsy is described together with an evaluation of its possible role in prenatal diagnosis.