TOP TAKE-AWAYS: RISK OF MISCARRIAGE AFTER AMNIOCENTESIS: FACTS AND PERCEPTIONS

Amniocentesis, the sampling of amniotic fluid using a hollow needle inserted into the uterus, is the most common invasive procedure used to diagnose genetic conditions prenatally (Eddleman et al., 2006).

When faced with the decision of whether to undergo amniocentesis, most women experience some anxiety around making that decision.  This is likely because there is well-documented risk of miscarriage associated with the procedure.

What the exact rate of risk is varies a bit among investigators and organizations.  The CDC released a statement that the risk of miscarriage is between .25 and .5%, or  1 in 200.  In 2006, the First and Second Trimester Evaluation of Risk (FASTER) trial calculated the risk of miscarriage after amniocentesis to be 1/1600 or 0.006% higher than for those who did not undergo amniocentesis (Eddleman et al., 2006).  In 2007, the American College of Obstetricians and Gynecologists (ACOG) published the rate of miscarriage associated with amniocentesis as 1/300-1/500.  In all, these risks are very low.  

When attempting to weigh the risk of undergoing an amniocentesis, most women seek the guidance of a genetic counselor. Nuccio et al (2015) found that women were more likely to be able to correctly identify the numeric risk of amniocentesis related miscarriage following genetic counseling.  However, even though they were able to more accurately cite the correct statistics for risk, Nuccio et al (2015) found that this did not necessarily change women’s perception of risk.  They found that rates alone are an incomplete picture of how women evaluate the risk associated with amniocentesis.  Nuccio et al. (2015) investigated what factors, other than risk rates themselves, influenced their risk perceptions. They found that 1) having a friend or relative with a personal or family history of a genetic disorder and 2) having a child already were associated with lower risk perception.  

In summary, although it can be beneficial for women to know more about specific rates of risk, it is helpful for individuals supporting these women to understand that the emotions and perceptions associated with evaluating risk go beyond numbers and statistics. 

Nuccio, R., Hashmi, S. S., Mastrobattista, J., Noblin, S. J., Refuerzo, J., Smith, J. L., & Singletary, C. N.(2014). Influence of anchoring on miscarriage risk perception associated with amniocentesis. Journal of Genetic Counseling, 24, 278-284. doi: 10.1007/s10897-014-9761-0.