Article Text

Download PDFPDF

Does assessment of signs and symptoms add to the predictive value of an algorithm to rule out pregnancy?
  1. John Stanback, PhD, Senior Associate1,
  2. Marlina Nasution, PhD, Biostatistician1,
  3. Nuru Nakintu, MD, Lecturer2 and
  4. Zahida Qureshi, MB BS, M Med, Senior Lecturer3
  1. Family Health International, Research Triangle Park, NC, USA
  2. Department of Obstetrics and Gynaecology, Makerere University, Kampala, Uganda
  3. Department of Obstetrics and Gynaecology, University of Nairobi, Nairobi, Kenya
  1. Correspondence to Dr John Stanback, Family Health International, PO Box 13950, Research Triangle Park, NC 27709, USA. Tel: +1 919 544 7040. Fax: +1 919 544 7261. E-mail: jstanback{at}


Background A World Health Organization-endorsed algorithm, widely published in international guidance documents and distributed in the form of a ‘pregnancy checklist’, has become a popular tool for ruling out pregnancy among family planning clients in developing countries. The algorithm consists of six criteria excluding pregnancy, all conditional upon a seventh ‘master criterion’ relating to signs or symptoms of pregnancy. Few data exist on the specificity to pregnancy among family planning clients of long-accepted signs and symptoms of pregnancy. The aim of the present study was to assess whether reported signs and symptoms of pregnancy add to the predictive value of an algorithm to rule out pregnancy.

Methods Data from a previous observational study were used to assess the performance of the algorithm with and without the ‘signs and symptoms’ criterion. The study group comprised 1852 new, non-menstruating family planning clients from seven clinics in Kenya.

Results Signs and symptoms of pregnancy were rare (1.5%) as was pregnancy (1%). Signs and symptoms were more common (18.2%) among the 22 clients who tested positive for pregnancy than among the 1830 clients (1.3%) who tested negative, but did not add significantly to the predictive value of the algorithm. Most women with signs or symptoms were not pregnant and would have been unnecessarily denied a contraceptive method using the current criteria.

Conclusions The ‘signs and symptoms’ criterion did not substantially improve the ability of the algorithm to exclude pregnant clients, but several reasons (including use of the algorithm for intrauterine device clients) render it unlikely that the algorithm will be changed.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.