The early prenatal sonographic diagnosis of renal agenesis: Techniques and possible pitfalls

Out of 13 252 cases in which fetal bilateral echogenic kidneys were detected by transvaginal sonography between 12 and 18 weeks' gestation, there were nine fetuses where oval hypoechogenic masses were detected in the renal bed. In five fetuses where hypoechogenic masses in the renal bed were sonographically visualized, postabortal examination was compatible with renal agenesis and the hypoechogenic masses proved to be enlarged adrenals. In three additional cases, unilateral renal agenesis was accompanied by unilateral enlarged adrenals, radiologically confirmed postnatally. In one case, a false-positive sonographic diagnosis of Potter syndrome was made because of bilateral hypoechogenic masses in the renal bed. Postabortal examination detected hypoplastic kidneys, but of normal histology, in a dyskaryotic fetus with trisomy 22. In four cases of renal agenesis, the amniotic fluid was of normal volume until the 17th week. In two of the five cases of Potter syndrome, a cystic structure, compatible with the urinary bladder, was detected in the pelvis at 14 weeks. The diagnostic criteria for renal agenesis in the early fetus differ from those used in the second half of gestation.     

Prenatal diagnosis of gall bladder anomalies—report of 17 cases

We describe here 17 cases of fetal gall bladder anomalies, detected as early as the 14th week of gestation, out of 10 016 fetal systemic examinations performed by us in the last 6 years (015 per cent). In seven cases, agenesis of the fetal gall bladder was detected. The diagnosis was confirmed by post-abortal examination in five cases and in two post-partum. In six other cases, a left-sided gall bladder and in one case, a ‘floating’ gall bladder were detected at 15 weeks' gestation. In two cases, a septated or bilobed gall bladder was visualized. None of these 15 cases was dyskaryotic, but in five cases, two with agenesis and three left-sided gall bladders were associated with other fetal malformations. In two other cases, the gall bladder appeared dysmorphic on sonographic examination and in both of them intrauterine growth retardation and other anomalies were detected. Trisomy 18 was diagnosed by amniocentesis in one of them. According to our experience, failure to visualize the fetal gall bladder by the 15th gestational week is diagnostic of its absence and should raise the differential diagnosis between gall bladder atresia, which has a good prognosis, and external biliary atresia, which has a poor prognosis. Further experience is needed to characterize the various gall bladder malformations and their prognosis.     

Transvaginal sonography—detection of findings suggestive of fetal chromosomal anomalies in the first and early second trimesters

Over a 4-year period, 14 dyskaryotic fetuses were diagnosed by amniocentesis, performed after early detection of malformations using transvaginal sonography (TVS). These 14 dyskaryotic fetuses were detected out of 4878 sonographic screenings performed by TVS between 9 and 16 weeks' gestation. Twenty-eight per cent of the referrals were at high risk and 72 per cent were at low risk for fetal malformations. Two hundred and twenty-nine fetuses (4.7 per cent) of the screened population had 265 anomalies, 39 per cent of them being transient. In 7 of the 14 dyskaryotic fetuses (50 per cent), the sonographically detected anomalies were transient, being undetected by follow-up sonographic screenings at later gestational ages (⩾18 weeks). Postponing the first sonographic scan aimed at malformation detection to a later gestational age may lead to transient anomalies and their associated dyskaryosis being missed.     

Anencephaly in a fetus with osteogenesis imperfecta: Early diagnosis by transvaginal sonography

Early prenatal diagnosis of osteogenesis imperfecta at 14 weeks' gestation by transvaginal sonography is reported. An anencephalic fetus was found at autopsy, although on sonographic examination complete brain tissue had been observed. A possible explanation for these findings and theories on the pathogenesis of anencephaly are discussed.     

Short-rib polydactyly syndrome (SRPS) type III diagnosed during routine prenatal ultrasonographic screening. A case report

The prenatal diagnosis of skeletal dysplasias is often initiated by the finding of a shortened extremity during a routine sonographic examination. Second-trimester diagnosis of these anomalies allows the couple to consider the option of terminating a pregnancy when a lethal anomaly is detected. A 21-year-old Bedouin woman underwent routine ultrasonographic screening at 20 weeks' gestation. Severe micromelia, a narrow thorax with shortened ribs, and postaxial polydactyly were detected. The patient delivered a male dwarf at 20 weeks' gestation following prostaglandin induction of labour for a diagnosis of short-rib polydactyly syndrome type III. The prenatal ultrasonographic diagnosis of short-rib polydactyly syndrome type III was made at 20 weeks' gestation, allowing termination of the pregnancy. A proper sonographic approach to skeletal dysplasias allows both early detection and differentiation between lethal and non-lethal anomalies.     

The significance of early second-trimester sonographic detection of minor fetal renal anomalies

A study of 6350 consecutive transvaginal ultrasound examinations was performed as part of a routine fetal evaluation. Twenty-one cases (0.33 per cent) of early second-trimester sonographic detection of minor renal abnormalities (unilateral renal agenesis, pelvic kidney, and double collecting system) are presented. The sonographic diagnosis was made at 14–18 weeks of pregnancy and confirmed, in all of the 21 fetuses, postnatally or by post-mortem. A high incidence of associated fetal anomalies (24 per cent) and parental renal abnormalities (14 per cent) was demonstrated. Transvaginal sonography was found to be a useful tool for diagnosing these renal anomalies as early as 14 weeks of pregnancy. The likelihood of various associated anomalies and long-term implications on renal function raise questions concerning the prenatal management of such patients.     

Prenatal sonographic signs of possible fetal genital anomalies

The sonographic markers of female and male external genitalia have been documented in early and late gestation. The aim of the present study was to report our experience of possible sonographic markers of fetal genital anomalies. Sonography was performed with a vaginal probe in early gestation and an abdominal sector scanner in advanced gestation. The following genital anomalies were observed: hypospadias, epispadias, ambiguous genitalia, and testicular feminization or Smith-Lemli-Opitz syndrome. It is therefore concluded that prenatal diagnosis of some genital anomalies is now possible.     

Prenatal diagnosis of Apert syndrome: report of two cases

Two de novo cases with Apert Syndrome detected prenatally are presented herein. In the first, fetal ultrasound findings of syndactyly of the hands, craniosynostosis and proptosis resulted in a prenatal diagnosis in the nineteenth week of gestation. This is the earliest prenatal diagnosis of this syndrome in a not-at-risk case. Following counseling, this pregnancy was terminated and subsequent pathological examination and DNA analysis confirmed the diagnosis of Apert Syndrome and coarctation of the aorta. In the second case, fetal ultrasound at 21 weeks' gestation revealed a hypoplastic left heart and clover-leaf skull. Following counseling, this pregnancy was also terminated. Further examination of the fetus and DNA analysis led to a diagnosis of Apert Syndrome. These cases emphasize the need to complete a thorough fetal ultrasound in cases with potentially lethal cardiac abnormality and the importance of incorporating a fetal pathologist, as well as a medical geneticist, in the investigations performed after delivery or pregnancy termination when a fetal abnormality is detected on ultrasound. Copyright © 2003 John Wiley & Sons, Ltd.     

Early transvaginal sonographic diagnosis of alobar holoprosencephaly

Holoprosencephaly is a cerebral anomaly resulting from incomplete cleavage of the primitive prosencephalon or forebrain. Early detection of this anomaly is very important since the most severe form is incompatible with life. The diagnosis also signals the need for a chromosomal determination since chromosomal abnormalities have been associated with this anomaly. An early diagnosis of alobar holoprosencephaly at 14 weeks' gestation, employing transvaginal sonography, is reported. Our findings are compared with prenatal transabdominal sonographic findings of holoprosencephaly which have been reported during the last decade in the literature.     

Diagnosis of polyhydramnios in early gestation: Indication for prenatal diagnosis?

Previously published reports have indicated that idiopathic polyhydramnios may be associated with trisomies 18 and 21 and that chromosomal analysis is indicated. Furthermore, the natural history and fetal outcome of polyhydramnios diagnosed in early gestation have not been well delineated. We identified 138 pregnancies with polyhydramnios prior to 26 weeks' gestation. Of 131 complete cases, 21 were diagnosed as severe, 18 as moderate, and 92 as mild polyhydramnios. Congenital abnormalities were noted in 18 of 21 severe cases (86 per cent). Two of the remaining three cases were twin-to-twin transfusion. Thirteen of 18 cases with moderate polyhydramnios (72 per cent) were associated with anomalies; six of the remaining cases were twin-to-twin transfusion. Sixteen of 92 cases of mild polyhydramnios (17 per cent) were associated with congenital abnormalities. In 69 of 76 cases of mild hydramnios not associated with anomalies (91 per cent), the hydramnios resolved prior to delivery. Only 2 of 16 (13 per cent) associated with anomalies resolved. In 4 of 5 cases (80 per cent) with moderate hydramnios and no anomalies, the amniotic fluid volume was normal on subsequent ultrasound. No case of moderate polyhydramnios associated with anomalies or maternal conditions nor any case of severe polyhydramnios resolved. There were seven cases of chromosomal abnormalities in this series; all were associated with sonographic findings in addition to the presence of polyhydramnios. On the basis of these data, we doubt the benefit of amniocentesis following the early diagnosis of idiopathic polyhydramnios in the absence of other ultrasound findings.     

The development of the fetal eye: In utero ultrasonographic measurements of the vitreous and lens

Our objective was to establish nomograms for fetal eye measurements from 12 weeks' gestation by using transvaginal and transabdominal high-resolution ultrasound techniques. A prospective cross-sectional study was performed on 450 normal singleton pregnancies between 12 and 37 weeks' gestation. Vitreous and lens circumferences were measured by transvaginal ultrasonography until 17 weeks, and by abdominal ultrasound between 18 and 37 weeks' gestation. Regression analyses were used to create nomograms, and several transformations were done to obtain linearity. Eye measurements of 12 fetuses at risk for ocular disturbances were plotted on the constructed nomograms. Linear relationships were fitted between vitreous (r²=0.79) and lens (r²=0.88) circumferences and gestational age. In addition, there was a significant correlation between these measurements and the biparietal diameter. Data of the fetuses at risk showed that disturbances in ocular growth were associated mainly with abnormal cerebral development. These normative data may be helpful in the prenatal diagnosis of suspected congenital syndromes that include, among their manifestations, ocular growth disturbances such as microphthalmos and anophthalmos.     

Extraction of DNA from amniotic fluid cells for the early prenatal diagnosis of genetic disease

Ten-ml samples of amniotic fluid were taken from pregnancies being terminated at 8–14 weeks' gestation. DNA was extracted from the amniotic cells by sequential centrifugation and analysed using the polymerase chain reaction (PCR). Fifteen samples were analysed for evidence of maternal contamination using Mfd5 oligo-nucleotide primers for repeat polymorphisms. Ten amniotic fluid samples were tested for the Delta-F₅₀₈ deletion characteristic of cystic fibrosis to demonstrate a diagnostic application for the technique. In each case, DNA extracted from fetal tissue from the same pregnancy was included in the controls. In 14 of the 15 cases tested with the Mfd5 primers, both the amniotic fluid DNA and the fetal DNA showed no evidence of contaminating DNA. In one case, neither the amniotic fluid cells nor the fetal cells yielded results. In nine of the ten cases tested with the Delta-F₅₀₈ primers, the amniotic fluid cell DNA provided accurate information about the genetic status of the fetus; in the tenth, the fetal DNA failed to amplify. The results indicate that adequate DNA can be extracted from amniotic fluid from 8 weeks' gestation onward and these samples are suitable for prenatal diagnosis using PCR.     

Fetal echocardiography using transvaginal and transabdominal probes during the first period of pregnancy: A comparative study

The authors compare the diagnostic possibilities of fetal transabdominal echocardiography versus transvaginal echocardiography. A larger diagnostic capacity is verified in different gestation ages with transvaginal probe between the 11th and 14th week of gestation. The results are emphasized by colour Doppler.     

Ultrasound observation of amnion dysmorphism at 14.5–16 weeks

The presence of chorio-amniotic separation and amnion anomalies was recorded in 9500 patients referred for vaginal ultrasound examination at 14.5–16 weeks' gestation. In all patients with a change in the amnion, a search for fetal anomalies was performed and pregnancy outcome was checked. Amnion dysmorphism was observed in 30 cases. The main findings were a floating membrane which changed its configuration when the uterus was tilted and multiple intrauterine amniotic sheets. In no case was attachment of the fetus to the membranes noted. There was no fetal abnormality and pregnancy outcome was favourable in all patients. In conclusion, ultrasound visualization of amnion dysmorphism in early pregnancy is not associated with an adverse pregnancy outcome.     

Genetic amniocentesis: 505 cases performed before the sixteenth week of gestation

Between May 1987 and November 1988, 505 early amniocentesis within the 15th week of gestation were performed at the First Department of Obstetrics and Gynaecology,‘L. Mangiagalli’ of the University of Milan and at the Department of Obstetrics and Gynaecology of ‘Gaslini’ hospital in Genoa. A total number often abnormal fetal karyotypes were diagnosed. In addition, one case of pseudomosaicism (not confirmed on fetal blood) and one case of osteogenesis imperfecta type II (observed at ultrasound examination) were also detected. Eleven pregnancies were therefore terminated because of an abnormal fetus. Out of 494 pregnancies (excluding terminated pregnancies) there were 16 fetal losses within the 28th week; ten of these occurred in the 2 weeks following the procedure. There were 475 live-births, of which 447 were term deliveries and the other 28 deliveries occurred before the 37th week of gestation.     

Prenatal diagnosis of congenital diaphragmatic hernia: Timing of visceral herniation and outcome

Ultrasonographic prenatal diagnosis of congenital diaphragmatic hernia is well established, but the correlation of prenatal detection with clinical outcome remains unclear. We report our experience with 15 cases of prenatally diagnosed congenital diaphragmatic hernia. Seven fetuses were detected at 14–16 weeks' gestation; two with a normal sonographic study at 15 and 16 weeks' gestation showed visceral herniation at 21 and 23 weeks, respectively. In the remaining six cases, a diaphragmatic hernia was found at ultrasonography after 24 weeks' gestation, while previous sonographic studies had been normal. All seven fetuses in whom a diaphragmatic hernia was diagnosed before 16 weeks' gestation were aborted; four of them had severe malformations or karyotype abnormalities. The two neonates who were diagnosed at 21 and 23 weeks' gestation died after surgical repair. In contrast, all six infants whose visceral herniation was diagnosed after 24 weeks of gestation, and whose sonographic studies at 15–23 weeks had been normal, are alive and well after corrective surgery. The results of this series suggest that the timing of visceral herniation into the thoracic cavity is a major indicator of the prognosis of these fetuses and that herniation that occurs after 25 weeks of gestation carries a favourable clinical outcome. Normal sonographic studies during the first half of pregnancy do not exclude the subsequent development of congenital diaphragmatic hernia, raising questions about the advisability of repeat examinations at later stages of gestation.     

Prenatal diagnosis of lissencephaly

We report two cases of prenatal detection of lissencephaly by high-resolution ultrasound. The first case studied was referred for high-risk obstetrical management and serial antenatal ultrasounds because of a family history of lissencephaly in an unresolved chromosomal abnormality. Diagnosis of a smooth gyral pattern consistent with lissencephaly was made at 32 weeks' gestation. The second case was referred for prenatal ultrasound because of a size versus dates discrepancy. The ultrasound examination showed a smooth gyral pattern at 31.5 weeks. In light of this ultrasound finding, a fetal blood sample was obtained and a chromosomal abnormality reported, confirming the diagnosis. To our knowledge, these cases represent the first report of the sonographic prenatal diagnosis of cerebral agyria or lissencephaly.     

Prenatal diagnosis in three cases of iniencephaly with unusual postmortem findings

Iniencephaly is a rare and lethal congenital malformation of the neural tube characterized by occipital bone defect, cervical dysraphism, fixed retroflexion of the fetal head and severe lordosis of the cervicothoracic spine. The etiology is unknown. Prenatally diagnosed cases of iniencephaly are rare because careful and early ultrasonographic evaluation is necessary. We present three cases of iniencephaly prenatally diagnosed by sonography at 20–22 weeks' gestation in which therapeutic abortion was induced. The sonographic findings were compatible with the postmortem findings. The present cases of iniencephaly were found to carry unusual associated malformations such as two lobes in the right lung and chorangiosis of the placenta. Only hypoplastic lungs have been reported by previous authors. We also studied the 677C→T mutation on the methylenetetrahydrofolate reductase gene in the parents in one of the present cases. The mother was found to be heterozygous for the 677CT polymorphism. Copyright © 2001 John Wiley & Sons, Ltd.     

Transvaginal sonographic detection of skeletal anomalies in the first and early second trimesters

We report the detection of 42 cases of musculoskeletal anomalies routinely screened by transvaginal sonography at 12-16 weeks of gestation out of 7325 examined pregnant women (incidence of 0·57 per cent).     

Unusual sonographic features of ARPKD

The classic sonographic appearance of the kidneys in fetuses with autosomal recessive polycystic kidney disease (ARPKD) has been well described. We report a case of enlarged kidneys with pyramidal hyperechogenicity quite similar to medullary nephrocalcinosis found in a fetus at 34 weeks' gestation. At 39 weeks, a female neonate was delivered and died after 22 h due to pulmonary insufficiency secondary to severe oligohydramnios. On pathological analysis, the gross and microscopic findings were typical of ARPKD with diffuse dilatation of tubules throughout. The fetal renal lobulation was prominent and on section, the pyramids were delineated within each lobule, accounting for the clear image of the pyramids observed on sonography. Copyright © 2006 John Wiley & Sons, Ltd.