External validation of a simple scoring system to predict pregnancy viability in women presenting to an early pregnancy assessment clinic

Abstract

A scoring system combining clinical history and simple ultrasound parameters was developed to predict early pregnancy viability beyond the first trimester. The scoring system has not yet been externally validated. This study aimed to externally validate this scoring system to predict ongoing pregnancy viability beyond the first trimester. Methods: This prospective observational cohort study enrolled women with singleton intrauterine pregnancies before 12 weeks of gestation. Women underwent examination and ultrasound scan to assess gestational sac size, yolk sac size, and fetal pulsation status. A pregnancy-specific viability score was derived in accordance with the Bottomley score. Pregnancy outcomes at 13 to 16 weeks were documented. Receiver-operating characteristic curve analysis was used to assess the discriminatory performance of the scoring system. Results: In total, 1508 women were enrolled; 1271 were eligible for analysis. After adjustment for covariates, miscarriage (13%) was significantly associated with age ≥35 years (odds ratio [OR]=1.99, 95% confidence interval [CI]: 1.19-3.34), higher bleeding score (OR=2.34, 95% CI: 1.25-4.38),

Diagnosis and prediction of miscarriage: can we do better?

“…Women who presented with vaginal bleeding, especially those having moderate or heavy bleeding, or blood clot per vagina were likely to subsequently miscarry. 9 In this issue of the Hong Kong Medical Journal, Wan et al 7 show similar findings. Interestingly, the authors found that moderate/ severe abdominal pain is a risk factor on univariate analysis, but this finding was not confirmed on multivariate analysis probably because vaginal bleeding was a cofounding factor.…”

“…15 In a recent study of 61 miscarriages, abnormal size of gestational sac and yolk sac appeared as early as 6 weeks of gestation, followed by abnormal changes in fetal heart rate and CRL at 7 and 8 weeks. 14 Although subchorionic haematoma was found to be a predictor of miscarriage in a metaanalysis 11 and in the study by Wan et al, 7 a recent study on pregnancies with detectable fetal heartbeat did not concur with these findings. 10 A meta-analysis of 15 studies including 1263 women with threatened miscarriage found that serum CA 125 is the only serum marker that is useful in predicting outcome of a pregnancy with a viable fetus, whereas serum human chorionic gonadotropin and progesterone are not useful.…”

“…4 Among women with intrauterine pregnancy of uncertain viability (PUV), the miscarriage rate is 49.3% to 52%. 7,8 Prediction of pregnancy outcome is a challenge and is necessary because it can assist counselling and decide frequency of follow-up ultrasonography. Demographic factors, ultrasound and biochemical markers either used alone or in combination have been described in the literature to predict miscarriage.…”

“…Interestingly, the authors found that moderate/ severe abdominal pain is a risk factor on univariate analysis, but this finding was not confirmed on multivariate analysis probably because vaginal bleeding was a cofounding factor. 7 When ultrasound shows fetal cardiac activity, the subsequent rate of miscarriage is 5.2% to 10.4%. 7,9,10 A meta-analysis of 18 eligible studies on ultrasound markers among 5584 women found that fetal bradycardia is the most significant marker, with a sensitivity of 84.2% in the prediction of miscarriage.…”

“…18 In their study, Wan et al report the first validation study of this scoring system on Chinese population, with AUC of 0.91 if only viable pregnancies were analysed. 7 Although this scoring system is described as simple, 7,17 its use requires extra time, and can be challenging to implement in a busy clinic setting. The use of this scoring system requires further studies in clinical settings.…”