The Association Between Gestational Age And Amniocentesis Complications


1 Department of Radiology, Islamic Azad University, Mashhad Branch

2 (Department of Radiology, Islamic Azad University, Mashhad Branch)


Background and Objective:
Amniocentesis for prenatal diagnosis is usually performed at 15 to 20 weeks of gestation. Early amniocentesis in the first trimester is associated with increased risk of fetal loss. However, the correlation between gestational age (GA) and incidence of complications after mid-trimester amniocentesis is unclear. The aim of this study was to evaluate whether there is a relationship between GA and complications of second-trimester amniocentesis or not.
Patients and Methods:
From 2005 to 2015, a total of 1555 second-trimester amniocentesis in singleton pregnancies were included. Exclusion criteria were induced abortion, abnormal amniocentesis results, maternal underlying disease or uterine malformations, fetal anomaly or abnormal findings in fetal ultrasound, and in vitro fertilization. All cases underwent follow-up for at least 1 month, and amniocentesis-related complications, including fetal loss (spontaneous abortion), vaginal bleeding, and amniotic fluid (AF) leakage were recorded. Patients who were not available for follow-up were also excluded.
A total of 1276 amniocentesis were studied. The mean maternal age and GA were 33 + 6.5 years and 17.2 + 2.3 weeks, respectively. No Complication occurred in 98% of cases. Overall, fetal loss rate was 0.7% (n=9), vaginal bleeding occurred in 1% (n=13), and AF leakage was detected in 0.3% (n=4). Among pregnancies with GA less than 17 weeks (n=719), a total of 15 complications (2.1%) occurred including 6 fetal loss, 6 vaginal bleeding, and 3 AF leakage. On the other hand, in pregnancies with GA of 17 weeks or more (n=557), a total of 11 complications (2%) were recorded, including 3 fetal loss, 7 vaginal bleeding, and 1 AF leakage. Comparing the two groups (GA< 17 and GA> 17), there were no statistically significant difference in cumulative complication rate (2.1% vs 2%, P= 0.889), and incidence of fetal loss (0.8% vs 0.5%, P= 0.739), vaginal bleeding (0.8% vs 1.3%, P= 0.456), or AF leakage (0.4% vs 0.2%, P= 0.636).
There is no association between amniocentesis-related complications and GA, based on the findings of our study. Therefore, second-trimester amniocentesis can be safely offered to pregnant patients, regardless of GA, without increased risk of adverse events.