The centralized prenatal genetics screening program of New York City III: The first 7,000 cases

Abstract

The Prenatal Diagnosis Laboratory of New York City (PDL) is a regional program for the prevention of genetic diseases. The administrative aspects of the establishment of the laboratory were described in papers I [Hsu, 1981] and II [Hsu and Benn, 1981] in this series. We now report our experience of the first 7,000 referrals to the laboratory. The laboratory achieved a success rate of 99.5% in obtaining a diagnosis. The frequency with which a repeat amniocentesis was required was 1.9%, usually attributable to inadequate initial amniotic fluid volume or condition. Cases were completed in an average time of 20.82 days. A total of 149 (2.13%) cytogenetic abnormalities were detected. There were 59 nonmosaic autosomal trisomies and 29 sex chromosome abnormalities. The incidence of unbalanced structural abnormalities (0.186%) was much higher than that reported in surveys of newborn infants largely because of the prenatal detection of cases with supernumerary chromosomes. The incidence of balanced structural abnormalities was also considerably higher than that found in surveys of the newborn population, in part because of the detection of subtle familial pericentric inversions of common chromosome regions (inv(Y)(p11q11), inv(2) (p11q13), and inv(1)(p11q13)). The incidence of cases with multiple independent chromosome abnormalities was no higher than expected by chance. A high incidence of mosaicism, pseudomosaicism, and maternal cell contamination was found. Screening for neural tube defects accounted for the detection of a further 16 abnormalities. Nearly all women with severely abnormal fetuses (trisomy 13, 18, 21) elected to terminate their pregnancy whereas only 62% of patients with a prenatally diagnosed sex chromosome abnormality elected to terminate their pregnancies. Full details of follow-up and confirmatory studies for unusual diagnoses are reported. Utilization of prenatal diagnosis in the New York City area has increased sharply since PDL became operational. The laboratory's success illustrates the role of a prenatal diagnosis laboratory that provides a service independent of the patient's financial status. The experience further shows the high degree of acceptance of prenatal diagnosis by individuals at high risk for a child with a genetic disorder.

Prenatal diagnosis of Down syndrome: a systematic review of termination rates (1995–2011)

“…The three US studies reviewed by Mansfield et al . were published in the 1980s . Evidence in our report from three population‐based California studies supports the notion that US termination rates decreased during the 1990s and early 2000s.…”

Decisions following the intrauterine diagnosis of sex chromosome aneuploidy

“…The literature suggests that in practice, when SCA is diagnosed in utero, termination is usually requested, even for sex chromosome mosaics [Holmes-Siedl et al, 1987;Nielsen and Pelsen, 1987;Anonymous, 1979;Benn et al, 1985;Verp et al, 19881. Verp et al [19881 have collected data on the results of 235 amniocenteses from 24 published studies (Table IV).…”

Parental decision following prenatal diagnosis of fetal chromosome abnormality

“…Results of most other large series are similar to ours (Table 11). That is, in the combined amniocentesis data, 96% of cases of autosomal aneuploidy were terminated, but only 67.3% of SCA (p < 0.001), and 36.2% of de novo balanced structural rearrange- Simpson et al, 1976Goldman et al, 1977Hook, 1978Golbus et al, 1979Bartsch et al, 1980Crandall et al, 1980Webb et al, 1980Verjaal et al, 1981Bou6 et al, 1982Daniel et al, 1982Squire et al, 1982Cruikshank et al, 1983Laurence et al, 1983Philip et al, 1983Young et al, 1983Vejerslev and Friedrich, Warburton, 1984Baird et al, 1985Benn et al, 1985Terzian et al, 1985Nielsen et al, 1986Tannenbaum et al, 1986Holmes-Siedle et al, 1987 Present…”