THEORY AND METHODS Conceptualisation, development, and evaluation of a measure of unplanned pregnancy

Study objective: To develop a measure of unplanned pregnancy that is valid, reliable, and appropriate in the context of contemporary demographic trends and social mores and can be used in a variety of situations, including the production of population prevalence estimates. Design: A two stage study design: qualitative (inductive) methods to delineate the construct of pregnancy planning, and quantitative/psychometric methods to establish the means of measurement. Setting: Eight health service providers (comprising 14 clinics, including antenatal, abortion, and one general practitioner) across London, Edinburgh, Hertfordshire, Salisbury, and Southampton in the UK. Participants: Samples comprised a mixture of pregnant (continuing pregnancy and opting for abortion) and recently pregnant (post-abortion and postnatal) women. At the qualitative stage, 47 women took part in depth interviews (20 of whom were re-interviewed after the birth of their baby). Items were pre-tested with 26 women, and two psychometric field tests were carried out with, respectively, 390 and 651 women. Main results: A six item measure of unplanned pregnancy was produced. Psychometric testing demonstrated the measure’s high reliability (Cronbach’s a= 0.92; test-retest reliability = 0.97) and high face, content, and construct validity. Women’s positions in relation to pregnancy planning are represented by the range of scores (0–12). Conclusions: A psychometric measure of unplanned pregnancy, the development of which was informed by lay views, is now available. The measure is suitable for use with any pregnancy regardless of outcome (that is, birth, abortion, miscarriage) and is highly acceptable to women.