Abstract
 Objective: There is a high incidence of birth defects in China, and prenatal diagnosis is an important method of intervention. This study aims to describe the clinical indications and cytogenetic results of amniocentesis cases in central China.
Methods: We retrospectively reviewed cases at the Maternal and Child Care Service Centre in Henan Province from January 2012 to December 2014. A total of 4497 at-risk mothers (risk factors: advanced maternal age, history of intrauterine fetal death or aborted fetuses, chromosomal abnormality in one of the parents, high-risk maternal serum screening results, and abnormal ultrasonographic findings in the first or second trimester) were recruited for amniocentesis (AS). The subjects included were between 11–14 and 18–22 weeks of gestation. All cases were divided into two groups based on instrument-independent or instrument-dependent indications. Results: A total of 4146 cases were analyzed. Of these, chromosomal abnormalities were detected in 232 cases (5.6%), and autosomal aneuploidy, including trisomy 21 and trisomy 18, was found to be the most common (55.7%) chromosomal abnormality. The mean age of 29.94 years was not expected as all mothers older than 35 years old were routinely offered amniocentesis at the time of the study. Amniocentesis was carried out in 1711 cases because of instrument-independent indications, and 285 of these cases were diagnosed with chromosomal abnormality. In 2376 cases, amniocentesis was conducted because of instrument-dependent indications, and 176 of these were diagnosed with chromosomal abnormality. Thus, 5.6% of the cases were diagnosed with chromosomal abnormalities, and autosomal aneuploidy, including trisomy 21 and trisomy 18, were the most common chromosomal abnormalities detected in the present study. Conclusion: Our result indicated the significance of instrument-independent indications in the screening of chromosomal abnormalities, especially in developing areas. Birth defects may be reduced by paying more attention to the patients’ history of medication.