Karyotype analysis of amniotic fluid cells and report of chromosomal abnormalities in 15,401 cases of Iranian women

Abstract

The aim of present study was to assess the karyotypes of amniotic fluid cells and find the frequency of chromosomal abnormalities and their significance in clinical setting. A total of 15,401 pregnant women were assessed from March 2016 to May 2019, and 14,968 amniotic fluid samples were successfully cultured. These fetuses were grouped according to different indications including advanced maternal age, abnormal nuchal translucency (NT) values, positive first/second trimester screening results, high risk NIPT results, very low PAPP-A and free β-hCG multiples of the normal median (MoM) results, abnormal ultrasound findings or previous history of chromosomal abnormalities. Results indicated the presence of normal karyotype in 90.2% (13,497/14,968) of fetuses. Totally, 46.4% (6945/14,968) of fetuses were 46,XX and 43.8% (6552/14,968) had 46,XY chromosome pattern. A total of 1077 abnormal karyotypes were found among 14,968 fetuses, thus the rate of abnormal fetuses was calculated to be 7.2% (1072/14,968). Meanwhile, a total of 394 cases (2.8%) had a normal polymorphism in their karyotype. In other words, abnormal karyotypes were detected in one of 13.9 cases of patients underwent amniocentesis. Down syndrome, Edward’s syndrome, abnormal mosaicisms and Patau’s syndrome were detected in 4.4% (659/14,968), 0.57% (85/14,968), 0.49% (74/14,968) and 0.24% (36/14,968) of cases, respectively. Sex chromosomal abnormalities including Klinefelter syndrome, Turner syndrome and 47,XXX karyotype were detected in 64 cases (0.43%). In this article, the rates of chromosomal abnormalities are compared between different groups of patients based on the advanced maternal age, abnormal NT values, very low PAPP-A and free β-hCG MoMs results, and positive FTS results. The current investigation provides insight into the most appropriate indications for amniocentesis in Iran.

Extreme βHCG levels in first trimester screening are risk factors for adverse maternal and fetal outcomes

“…We also found associations between some parameters of adverse maternal/fetal outcomes and fetal sex as well as calculated risk of trisomies 18 and 21 in FTS which is in line with our previous study 13 .…”

“…In our recent study, we have suggested high risk non-invasive prenatal testing (NIPT), PAPP-A MoM < 0.2 and free βHCG MoM > 5 or < 0.2 as important indications for necessity of invasive testing in pregnancy with appropriate OAPR values 13 . In the current study, we have collected data about perinatal complications and adverse fetal/maternal outcomes from patients with free βHCG MoM > 5 or < 0.2 in a period of 8–12 month after delivery.…”

“…Our recent study in a large cohort of Iranian pregnant women came for amniocentesis has led to identification of the importance of free βHCG multiples of the normal median (MoM) levels < 0.2 or > 5 as indicators of adverse pregnancy outcomes 13 . Thus, we designed the current retrospective study to assess the maternal and fetal outcomes in pregnant women having these free βHCG MoM levels in their first trimester screening (FTS).…”

The likelihood of detecting abnormal karyotypes in fetuses with a single major anomaly or “soft” marker on ultrasonographic scanning

“…Chromosomal abnormalities are significant contributors to congenital defects and intellectual disability, presenting challenges for affected individuals and their families due to the lack of curative treatments. The prevalence of these disorders, occurring in one in 153 births, highlights the need for effective screening programs to identify affected fetuses at an appropriate gestational age (Younesi et al , 2021). Ultrasound has become an essential tool in fetal medicine, aiding in the detection and management of various conditions.…”

Relación de los factores de riesgo de alteraciones cromosómicas con el resultado citogenético fetal en gestantes

“…La EMA también es el principal motivo de indicación y fluctúa entre el 90,9 -72,3 % del total de casos estudiados. Los antecedentes personales y/o familiares de alteraciones cromosómicas se describieron entre el 11,6 -4,0 % y los hallazgos ultrasonográficos en el rango de 1,9 -8,1 % (1,(9)(10)(11)(12)(13). En la universidad del Zulia, se estudiaron 568 gestantes a las que se les hizo amniocentesis para estudio citogenético, de ellas el 40,9 % fueron por EMA, el 35,2 % por antecedente personal y/o familiar y el 13,8 % por alteraciones ecográficas del feto.…”