An investigation of the decision-making process for prenatal genetic testing

• Main Author: Muller, Cécile
• Other Authors: Cameron, Linda
• Published: ResearchSpace@Auckland 2012
• Online Access: http://hdl.handle.net/2292/13301

With rapid advances in genomics and maternal care, health professionals will be increasingly required to assist prospective parents make decisions about prenatal testing. However, little is known about the way people make such choices. The present project aimed to fill in this research gap and consisted of three internet-based studies. Study One aimed: 1) to design a model of the process of prenatal genetic testing decision-making, accounting for the complex interactions between variables previously shown to influence testing intention; and 2) to create psychometrically sound measures of the constructs of interest. Data was collected using a scenario which asked 143 New Zealand adults to imagine expecting a child, mentioned a genetic mutation responsible for an unnamed fatal birth-onset condition and described prenatal testing. Results from principal components analyses confirmed the suitability of the new scales for subsequent studies. Study Two aimed to: 1) validate the hypothetical model proposed in Study One, and; 2) assess the role of condition characteristics and demographic characteristics on reproductive decisions. Over 565 men and women of different family statuses (childless, expecting or parents) were randomly assigned to one of four scenarios which described genetic conditions of varying onset ages (early or late) and degrees of severity (nonfatal or fatal). Data were collected using the measures developed in Study One. Path analysis validated the decision-making model. ANOVAs revealed that onset age and severity did not influence testing intention. However, willingness to terminate an affected pregnancy was greater for the fatal (than the not fatal) and the early-onset (than the late-onset) conditions. Childless men (relative to childless women) reported greater testing intention, abortion willingness and subjective norms of the partner. Study Three assessed the roles of perceived procedure-related miscarriage, information modality and trait anxiety in reproductive choices. One hundred and ninety three New Zealand adults were randomly allocated to a message presented in text, print or video. The scales validated in Study One and two new measures (perceived likelihood of miscarriage and trait anxiety) were used to collect data. As expected, miscarriage likelihood predicted testing intention and anxious individuals reported stronger emotional responses to the message delivered in a video. Clinical and educational implications are discussed.