The aim of this thesis was to examine a large cohort of women undergoing pregnancy assessment before 12 weeks gestation, collecting demographic, symptom and ultrasound data. I aimed to examine the role of prior risk factors and initial ultrasound findings in the prediction of first trimester viability of these pregnancies. Further, I aimed to develop and validate models to counsel women in future about the likely chance of viability for any individual pregnancy. The hypotheses were: (1) There are prior risk and ultrasound factors that can predict likely pregnancy viability, (2) These factors can be used to predict pregnancy loss or ongoing viability in any particular pregnancy and (3) In predicting outcome, both mathematical models } and 'simple rules' (for everyday clinical use) can perform well. ) The prospective study included 1881 women, with median age 32 years and median gestational age at presentation of 50 days. 46% presented with bleeding and 36% with pain. The final outcome was an ongoing pregnancy in 885 (61.7%) and early pregnancy loss in 550 (38.3%) women. Both 'prior risks' (maternal age and bleeding score) and ultrasound factors (gestation and yolk sac size and fetal heart beat) predicted viability. Mathematical models developed showed that these factors used separately and when combined together predicted viability with accuracy. The final scoring system using both demographic and ultrasound variables together was proven to be highly accurate in prediction of pregnancy viability, performing with a sensitivity of 0.92, specificity of 0.73, positive predictive value of 84.7% and negative predictive value of 85.4%. All 3 study hypotheses were proven. The conclusion of this study is that using routinely collected demographic and ultrasound data an accurate individualised likelihood of ongoing viability can be offered to women in early pregnancy with and without symptoms of pain or bleeding.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:676895 |
| Date | January 2015 |
| Creators | Bottomley, Cecilia |
| Publisher | St George's, University of London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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