Incidence of non-age-dependent chromosomal abnormalities: a population-based study on 88965 amniocenteses

Abstract

Current knowledge about the incidence of chromosomal abnormalities in the general population comes from studies in newborns carried out in the 70s, before the era of widespread prenatal diagnosis. In the following years, data on frequency of chromosomal abnormalities in the second trimester of pregnancy have been used in conjunction with the data on the natural history of chromosomally abnormal fetuses to infer maternal age-specific rates of cytogenetic abnormalities in live-born infants. Starting from the data gathered in 1995 -1996 from all Italian cytogenetic laboratories (with 92% compliance to the study), we have compared the frequency of chromosomal abnormalities at amniocentesis in cases with maternal age of Z35 years (51 758 individuals) and cases with maternal age of o35 years (37 207 cases). The comparison confirmed the age-dependency of aneuploidies, whereas none of the structural abnormalities showed age-related differences. Furthermore, among the mosaic aneuploidies, trisomy 21 and 45,X/46,XX were found with a significantly higher incidence in older women. Chromosomal abnormalities that showed no significant difference between the two groups were summed for the overall national cohort, providing a general estimate of the incidence in the second trimester of pregnancy. The data provide critical background information for prenatal genetic counseling and for the planning of health care policy.

Noninvasive prenatal screening for fetal aneuploidy, 2016 update: a position statement of the American College of Medical Genetics and Genomics

“…43 This was higher for women older than 35 years compared to younger women (1/210 and 1/459, respectively). Conventional screening for aneuploidies does not detect sex chromosome aneuploidies.…”

“…In a large retrospective study of amniocentesis performed for maternal age, ultrasound findings, biochemical abnormalities, or familial indications, 1/14,830 patients had trisomy 2, 8, 12, or 22. 43 Detection of lethal chromosome abnormalities for which the natural course will be fetal loss has the potential to result in unnecessary diagnostic procedures and unnecessary pregnancy termination procedures. In addition to having a personal impact on patients, data collection in the public health sector could result in inflated pregnancy loss attributed to diagnostic procedures and maternal complications from pregnancy termination.…”

Clinical diagnostic testing for the cytogenetic and molecular causes of male infertility: the Mayo Clinic experience

“…Although these studies have different inclusion criteria, a meta-analysis was performed to generate cumulative frequencies ( Table 1). The cumulative frequency of autosomal abnormalities in these studies of infertile males is 3.5%, compared to 0.42% of people within the general population that are known to have balanced or unbalanced autosomal rearrangement [14]. 1.7% of infertile males are reported to have rearrangements of sex chromosomes by karyotyping, compared to the 0.10% among the general male population [14].…”

Karyotype analysis in large-sample infertile couples living in Central China: a study of 14965 couples

“…Chromosomal anomaly can produce abnormal gametes during meiosis, leading to a history of adverse pregnancy (recurrent pregnancy loss) or delivery outcomes (birth of congenital malformation fetus or dead fetus) [9,11]. The rate of chromosomal anomaly in general population is 0.37 %-1.86 % [1][2][3]. The rate of chromosomal anomaly in infertile population is 2-3 times the rate of chromosomal anomaly in general population [4-6, 8, 9].…”

“…The rate of chromosomal anomaly in the general population is 0.37 %-1.86 % [1][2][3]; while in the infertile population, it is as high as 3.95 %-14.3 % [4][5][6][7][8]. Chromosomal anomaly may decrease male potentia generandi and increase the history of female adverse pregnancy or delivery outcomes [9].…”