Antenatal screening for cystic fibrosis: a trial of the couple model

Abstract

Objective : To assess the delivery and acceptability of antenatal couple screening for cystic fibrosis. Carrier status was notified only when both members of a partnership had cystic fibrosis alleles and therefore a one in four risk of having an affected child. Design: Mouthwash samples were tested when both partners participated. Results were returned only to positive couples. Setting : Two large maternity hospitals in Edinburgh. Subjects : Screening was offered to all couples who booked at one of the two hospitals. Main outcome measures :(a) The take up of screening, carriers and carrier couples identified, take up of prenatal diagnosis, and numbers of affected fetuses detected; (b) questionnaire measures of patient satisfaction and stress. Results : Screening was offered to 8536 couples. 714 (8.4%) were regarded as ineligible, usually because of late booking or absence of a partner. 1900 (24.3%) of the remainder declined screening. Among the 5922 screened couples, four tested positive - that is, both partners were cystic fibrosis heterozygotes. All four elected to have prenatal diagnosis. There were three terminations of pregnancy because of an affected fetus, one couple having two successive pregnancies with affected fetuses. The participation rate was 76% for eligible couples (5922/7822) and 69% for all couples (5922/8536). Only 89 screened couples (1.5%) requested information on individual carrier status. No anxiety was detected among a cohort of the screened population, and 99% of questioned participants expressed satisfaction with the concept of couple screening. Conclusions : Antenatal couple screening is a20satisfactory and acceptable way of screening for cystic fibrosis and has been adopted as routine in the two trial hospitals.