Can doctors predict if a miscarriage is likely in the future?
When a women visits an early pregnancy unit can a doctor or nurse tell whether the pregnancy is likely to miscarry or not in the future. In a study by Cecilia Bottomley and colleagues it seems the answer may be yes.
At least a percentage risk of miscarriage can be given bases on some information such as the amount of bleeding, how many weeks pregnant a women is and the findings on an ultrasound scan. In this study the authors describe a mathematical model and simple scoring system – both predict pregnancy outcome with reasonable accuracy. Unfortunately there is little that can to alter the outcome of a pregnancy – but at least this work means women will have a little more information so they can know what to expect when they have a problem rather than being in a state of anxious uncertainty.
A model and scoring system to predict outcome of intrauterine pregnancies of uncertain viability.
To define the incidence and outcome of intrauterine pregnancy of uncertain viability (PUV) and to develop and assess the performance of a model and a scoring system to predict ongoing viability.
Of 1881 consecutive women undergoing transvaginal ultrasonography, a cohort of 493 women with an empty gestational sac < 20 mm in mean diameter, gestational sac < 25 mm in mean diameter and containing yolk sac only or an embryonic pole < 6 mm in maximum length and without visible heart activity were followed until the end of the first trimester. Women with multiple pregnancies or who underwent termination of pregnancy were excluded. Outcome measures were pregnancy viability at initial 7-14-day follow-up and first-trimester viability at 11-14 weeks. The data were split randomly into two sets (two-thirds and one-third, respectively) in order to first develop and then test a mathematical model and a ‘simple’ model in the prediction of viability at each outcome point, based on maternal demographics, ultrasound features and symptoms. The performance of each system was assessed by receiver-operating characteristics (ROC) curve analysis and calibration plots on a test dataset.
The incidence of PUV in this population was 29.2% (549/1881). Of the 493 pregnancies with initial (7-14 days) follow-up available, 307 (62.3%) were viable at this time and of the 444 pregnancies with follow-up at the end of the first trimester, 225 (50.7%) were still viable. Initial (7-14-day) viability was predicted by the model with an area under the ROC curve (AUC) of 0.837 (95% CI, 0.791-0.884) in the training dataset and 0.821 (95% CI, 0.756-0.885) in the test dataset. First-trimester (11-14-week) viability was predicted by the model with an AUC of 0.788 (95% CI, 0.734-0.842) in the training dataset and 0.774 (95% CI, 0.701-0.848) in the test dataset. The scoring system performed slightly worse than did the model, but had the advantage of being easily applicable.
When early pregnancy viability cannot be established immediately with ultrasound, use of either a logistic regression model or a scoring system allows an individualized prediction of first-trimester outcome.
Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
[PubMed - indexed for MEDLINE]
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