Antenatal screening for carriers of cystic fibrosis: randomised trial of stepwise v couple screening.
OBJECTIVE
To perform a rigorous comparative evaluation of stepwise and couple approaches to antenatal carrier screening for cystic fibrosis.


METHODS
Pragmatic randomised trial.


METHODS
Hospital antenatal clinic serving a regional population.


METHODS
2002 women (couples) attending for booking antenatal visit at less than 17 weeks' gestation with no family history of cystic fibrosis.


METHODS
Offering counselling and carrier testing for cystic fibrosis, either to women in the first instance (stepwise) or to couples (couple screening).


METHODS
Uptake rates; anxiety; knowledge of cystic fibrosis and carrier status (both partners); attitudes to health, pregnancy, the baby, and screening (both partners); and uptake of carrier testing by relatives.


RESULTS
Uptake of screening was the same for both approaches (90%). After delivery most women remembered test results and their meaning, but 53/253 (21%) of those with negative results of couple testing had forgotten that repeat testing would be advisable if they had a pregnancy with a new partner. With stepwise screening women identified as carriers had high levels of anxiety when results were received (mean anxiety score 52.3). This dissipated with a reassuring partner's result (carriers' mean anxiety score 36.1) to levels similar to those receiving negative results from couple screening. Of those receiving negative results, women who had stepwise screening were significantly less anxious than those who had couple screening (mean score with result 32.1 v 35.4, 95% confidence interval for difference -4.7 to -2.1).


CONCLUSIONS
Couple screening allows carriers to avoid transient high levels of anxiety, but is associated with more anxiety and false reassurance among most screenees who will test negative. Stepwise screening gives carriers and their relatives genetic information and is, in our opinion, the better method.
Miedzybrodzka
Z H
ZH
University of Aberdeen, Foresterhill.
Hall
M H
MH
Mollison
J
J
Templeton
A
A
Russell
I T
IT
Dean
J C
JC
Kelly
K F
KF
Marteau
T M
TM
Haites
N E
NE
D001007:Anxiety / Q000209:etiology; D003550:Cystic Fibrosis / Q000175:diagnosis*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D006580:Genetic Carrier Screening; D005817:Genetic Counseling; D005820:Genetic Testing / Q000379:methods* / Q000523:psychology; D007722:Health Knowledge, Attitudes, Practice; D006771:Hospitals, Maternity; D006801:Humans; D008297:Male; D010342:Patient Acceptance of Health Care; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods* / Q000523:psychology; D012044:Regression Analysis; D012606:Scotland