45,X karyotype: May the diagnosis be suspected on ultrasonic examination in the second trimester of pregnancy?

We report three cases of Turner's syndrome with cystic hygromata, which were diagnosed by routine ultrasound scanning before amniocentesis in the second trimester of pregnancy. Maternal and amniotic level of alpha-fetoprotein were normal. Karyotyping carried out afterwards showed a 45,X karyotype. Our data indicate, that cystic hygromata in Turner's syndrome may coexist with a normal amniotic fluid AFP, thus questioning the theory of leakage from the hygroma. It remains to be investigated if all cases of Turner's syndrome present a cystic hygroma in utero.     

Prenatal detection of monosomy 21 mosaicism

We report a case of chromosomal mosaicism for monosomy 21 revealed in amniotic fluid cell culture. Ultrasound examination at 19 weeks' gestation showed in utero growth retardation and a complex cardiac malformation. A repeated amniocentesis confirmed the presence of monosomy 21 mosaicism. In view of the sonographically detected fetal abnormalities, termination of pregnancy was elected.     

Prenatal diagnosis of giant cystic hygroma: Prognosis,counselling, and management; case presentation and review of the recent literature

Cystic hygromas have historically been associated with a grim prognosis when discovered during prenatal sonographic study of the fetus. This same grim prognosis is not observed by the paediatric surgeon who evaluates the neonate or paediatric patient. We present a fetal patient with a massive anterior cystic hygroma discovered in the third trimester prior to 30 weeks. This case and a review of the literature suggest tailoring the prognosis by category when counselling patients: (1) first trimester, normal karyotype-good; (2) first trimester, abnormal karyotype-poor; (3) second trimester and early third-poor to guarded; and (4) mid to late third trimester-good.     

Transabdominal chorionic villus sampling in the second trimester of pregnancy: Feto-maternal transfusions in relation to pregnancy outcome

Volumes of feto-maternal transfusions (FMTs) in transabdominal chorionic villus sampling (TACVS) in the second trimester of pregnancy were calculated from the difference between maternal alpha-fetoprotein (AFP) concentrations before and 1 h after TACVS. In 50 pregnancies, there existed no correlation between FMT volume and the amount of villi collected or the number of TACVS attempts. The expected risk of fetal exsanguination due to very voluminous FMT could not be substantiated. In one case, immunization could have been the cause of hydrops fetalis, although only a volume of 0.15 ml could be calculated.     

Early second-trimester sonographic appearance of occipital haemangioma simulating encephalocele

Encephalocele is the most common cause of occipital midline extracranial mass associated with hydrocephalus. A case is presented where an occipital extracranial mass associated with hydrocephalus which was detected on second-trimester ultrasound examination turned out to be a haemangioma, a relatively benign lesion. We suggest that haemangioma should be considered in the differential diagnosis of extracranial masses detected prenatally.     

Antenatal sonographic diagnosis of arthrogryposis multiplex Congenita

Arthrogryposis Multiplex Congenita (AMC) was suspected on ultrasound examination of a fetus at 30·5 weeks of gestation. The criteria for establishing this prenatal diagnosis as well as the importance of establishing the diagnosis at any gestational age are discussed. The diagnosis of AMC was confirmed at birth in this case.     

Prenatal diagnosis of Pallister–Killian syndrome: Resolution of cytogenetic ambiguity by use of fluorescent in situ hybridization

We report a case of Pallister-Killian syndrome initially diagnosed prenatally as tetrasomy 21. A 33-year-old primiparous woman was noted at 24 weeks' gestation to have moderate polyhydramnios. Ultrasonography showed diminished fetal stomach filling, hydronephrosis, and prominence of the cisterna magna. Cytogenetic analysis of cultured amniocytes was initially interpreted as mosaic tetrasomy 21: 46,XX/47,XX,+i(21q). The patient was then referred to our centre for genetic counselling. At 34 weeks' gestation, a dysmorphic infant was delivered and died within 30 min. Physical features were consistent with the Pallister-Killian syndrome. Renal, gastrointestinal, and central nervous system anomalies were found at post-mortem examination. Analysis of peripheral lymphocytes revealed 5 per cent of cells with a marker chromosome, while 92 per cent of cultured fibroblasts had this same marker. Fluorescent in situ hybridization (FISH) using an alpha-satellite probe for chromosomes 13 and 21 failed to hybridize to the marker, while a chromosome 12 centromeric probe unequivocally identified it as an i(12p). Use of FISH can provide rapid, specific prenatal diagnosis of ambiguous marker chromosomes and improve prenatal counselling.     

A revisit of trisomy 20 mosaicism in prenatal diagnosis—an overview of 103 cases

One hundred and three cases with prenatal diagnosis of trisomy 20 mosaicism through amniocentesis were reviewed. Approximately 90 per cent (90/101) of the cases were associated with grossly normal phenotype. It is likely that, in the majority of cases, cells with trisomy 20 were extraembryonic in origin or largely confined to the placenta. However, in some cases, the cells with trisomy 20 were confined to certain specific fetal organs or tissues such as kidney, skin, etc. Cytogenetic follow-up studies in liveborns should include a culture from urine sediment.     

Transabdominal villus sampling in early second trimester: A safe sampling method for women of advanced age

Transabdominal chorionic villus sampling (TA-CVS) was performed in 707 viable singleton pregnancies to exclude chromosomal abnormalities. Maternal age ranged between 36 and 49 years (mean 37·9 years); gestational age varied between 10·2 and 18·3 weeks (mean 13·3 weeks). In 639 women (90·4 per cent), a sufficient amount of chorionic tissue (⩾ 10 mg) was obtained after one needle insertion; in 66 women (9·3 per cent) two insertions were needed. An abnormal chromosome pattern was established in 19 cases (2·9 per cent). Vaginal bleeding or spotting within 28 days after TA-CVS occurred in 11 cases (1·5 per cent). The completed follow-up of 678 chromosomally normal pregnancies showed an overall fetal loss rate of 2·6 per cent before 28 weeks. The overall perinatal mortality was 0·9 per cent. When relating fetal loss to gestational age at TA-CVS, this was 6·6 per cent in women sampled before 12 weeks against only 1·8 per cent after 12 weeks. At the same time, the percentage of fetal loss occurring within 2 weeks following the procedure was 75 and 30 per cent, respectively. It is suggested that these data reflect the decline in spontaneous abortion rate during this particular period of pregnancy. It is concluded that TA-CVS is an effective procedure which, when performed after the natural decrease of fetal loss, appears to be a safe option for women of advanced maternal age.