Amniotic band syndrome causing fetal head deformity

Amniotic band syndrome is a rare cause of fetal head deformity. We report a case in which antenatal ultrasound in the first half of pregnancy indicated the presence of a fetal cranial deformity, reported as either anencephaly or encephalocele. At assessment autopsy, disruption of the fetal skull was associated with amniotic band formation. Appropriate genetic counselling can be offered to such patients only when detailed pathological examination of the aborted fetus is made. The recurrence rate of amniotic band syndrome does not warrant amniocentesis in a subsequent pregnancy.     

Amniotic fluid pregnancy-specific β1-glycoprotein (SP1) in Meckel's syndrome: A new test for prenatal diagnosis?

Amniotic fluid levels of pregnancy-specific β₁-glycoprotein (SP₁) were elevated in four pregnancies with Meckel's syndrome at 16 and 26 weeks, and the levels of hCG were also elevated in three out of four cases. These findings suggest a potential new application of SP₁ measurement for prenatal diagnosis.     

First-trimester biochemical screening for fetal chromosome abnormalities and neural tube defects

Alpha-fetoprotein (AFP), unconjugated oestriol (UE3), intact human chorionic gonado-trophin (intHCG), and the free β subunit of chorionic gonadotrophin (FβHCG) were investigated in a series of 21 chromosomally abnormal and 14 open neural tube defect pregnancies ascertained from a series of 14 000 prospectively collected maternal serum samples at 6–14 weeks' gestation. In 16 cases of Down's syndrome, significant reductions were found for AFP (0.65 multiples of the normal median) and UE3 (0.67 MOM). IntHCG levels were unaltered (0.97 MOM) but a significant increase was found for FβHCG (1.96 MOM). Significant correlations were found for AFP and UE3 in the controls and for int HCG and FβHCG in both the control and the Down's syndrome pregnancies. In a group of five trisomy 18 pregnancies, median MOMs were for AFP 0. 71 , for UE3 0. 34 , for intHCG 0. 27 , and for FβHCG 0.15. None of 13 pregnancies with open neural tube defects at 8-13 weeks gestation had elevated maternal serum AFP levels, whereas matched second-trimester samples from the same pregnancies at 16-18 weeks gestation all had significantly elevated AFP levels. Thus, biochemical screening for chromosome abnormalities may be practicable in the first trimester using free β human chorionic gonadotrophin in combination with AFP and maternal age. However, a separate screening protocol using AFP at 15-18 weeks gestation would still be required for effective detection of neural tube defects.     

Ultrasound screening for chromosomal anomalies in the first trimester of pregnancy

For the last 6 years, sonographic signs for excessive fluid accumulation in the backs of 10- to 12-week-old fetuses have been looked for prior to transabdominal chorionic biopsy. In 1400 pregnancies, subsequent karyotype analyses revealed 28 cases of Down syndrome. In 15 ( = 54 per cent), a large fluid cushion over most of the back had been documented at the time of biopsy. Only a few chromosomally normal fetuses with the same peculiarity were observed. The cushion was also present in fetuses with trisomies 18 and 13 , and in Turner syndrome. Systematic first-trimester screening for nuchal fluid accumulation seems to be a recommended method for the detection of Down syndrome and other chromosome anomalies in young pregnant women at low risk. It compares favourably with current methods of maternal serum screening performed at 16–18 weeks which require a higher number of invasive procedures.     

Prenatal diagnosis and investigation of a fetus with chondrodysplasia punctata,ichthyosis, and Kallmann syndrome due to an Xp deletion

We report the prenatal diagnosis of a male fetus with X-linked recessive chondrodysplasia punctata (CDPX), steroid sulphatase (STS) deficiency, X-linked Kallmann syndrome (KAL), and a chromosome deletion at Xp22.31. Biochemical analysis of bone from this case indicates that CDPX is not a defect of vitamin K metabolism. Immunocytochemical study of the brain suggests that KAL is a defect in neuronal migration.     

Prenatal diagnosis in autosomal dominant Beckwith-Wiedemann syndrome

A 20-year-old woman with Beckwith-Wiedemann syndrome (BWS) was ultrasonographically appraised at intervals during her pregnancy. Unequivocal evidence for a diagnosis of BWS was obtained in the fetus and this was confirmed postnatally. Early ultrasound diagnosis enabled appropriate genetic counselling to be given; neonatal complications, such as hypoglycaemic episodes, were prevented.     

First-trimester maternal serum unconjugated oestriol and alpha-fetoprotein in fetal Down's syndrome

Maternal sera (MS) taken from 1396 women prior to chorionic villus sampling at 9–12 menstrual weeks were assayed for unconjugated oestriol (uE3) and alpha-fetoprotein (AFP). Median levels increased by 41 and 26 per cent per week respectively in normal pregnancies. There were 32 pregnancies with a chromosome abnormality. The median MS uE3 and AFP were 0.73 and 0.75 multiples of the median (MoM) respectively in the ten cases of Down's syndrome (DS) but not decreased in the other abnormalities. These results suggest that both uE3 and AFP may be useful in identifying DS in the first trimester. Additional prospective studies are needed to confirm these findings.     

Prenatal diagnosis of 45,X/46,XX mosaicism: True mosaicism in only one of four primary cultures

45,X/46,XX mosaicism was found in only one of four primary amniotic fluid cultures. Repeat amniocentesis revealed 45,X/46,XX mosaicism in all four primary cultures. Mosaicism was confirmed in tissues from the abortus.     

Prenatal treatment of fetal hydrops associated with the hypertelorism-dysphagia syndrome (opitz-g syndrome)

Non-immunological fetal hydrops diagnosed prenatally presents a difficult diagnostic and therapeutic problem. In the case presented, fetal hydrops was recognized at 19 weeks gestation and no specific cause was found prenatally in spite of extensive investigations. The fetal hydrops was treated in utero by thoracocentesis and an intravenous infusion of albumin carried out at fetoscopy. After birth the infant was recognized to have the hypertelorismdysphagia syndrome (or Opitz-G syndrome, McK no. 30710). This autosomal dominant syndrome consists of hypertelorism, laryngeal abnormalities, swallowing difficulties, hyprospadias and an imperforate anus. Fetal hydrops has been reported on one previous occasion in this syndrome. The intrauterine treatment given in this case may have been successful in reducing the neonatal complications of the Opitz-G syndrome.     

Incidental detection of premature centromere separation in amniocytes associated with a mild form of Roberts syndrome

Premature centromere separation (PCS) was detected in amniocytes after an amniocentesis was done because of markedly elevated maternal serum alpha-fetoprotein values in a healthy primiparous young woman. PCS has been associated with the Roberts-SC phocomelia syndrome (RS). By 23 weeks' gestation, ultrasonic evaluations did not reveal abnormal fetal development. The pregnancy continued and a male infant was born with mild manifestations of RS. PCS was confirmed in cord blood lymphocytes. This case illustrates that PCS, when detected in amniotic fluid cell cultures, requires a thorough evaluation.