Risk score to stratify miscarriage risk levels in preconception women

Abstract

Spontaneous miscarriage is one of the most common complications of pregnancy. Even though some risk factors are well documented, there is a paucity of risk scoring tools during preconception. In the S-PRESTO cohort study, Asian women attempting to conceive, aged 18-45 years, were recruited. Multivariable logistic regression model coefficients were used to determine risk estimates for age, ethnicity, history of pregnancy loss, body mass index, smoking status, alcohol intake and dietary supplement intake; from these we derived a risk score ranging from 0 to 17. Miscarriage before 16 weeks of gestation, determined clinically or via ultrasound. Among 465 included women, 59 had miscarriages and 406 had pregnancy ≥ 16 weeks of gestation. Higher rates of miscarriage were observed at higher risk scores (5.3% at score ≤ 3, 17.0% at score 4-6, 40.0% at score 7-8 and 46.2% at score ≥ 9). Women with scores ≤ 3 were defined as low-risk level (< 10% miscarriage); scores 4-6 as intermediate-risk level (10% to < 40% miscarriage); scores ≥ 7 as high-risk level (≥ 40% miscarriage). The risk score yielded an area under the receiver-operating-characteristic curve of 0.74 (95% confidence interval 0.67, 0.81; p < 0.001). This novel scoring tool allows women to self-evaluate their miscarriage risk level, which facilitates lifestyle changes to optimize modifiable risk factors in the preconception period and reduces risk of spontaneous miscarriage.

Figure 1

Study flowchart.

Figure 2

Proportion of women with miscarriages < 16 weeks gestation according to the risk scores (P-for-trend < 0.001). Scores 0–3 (< 10% miscarriage): low-risk; scores 4–6 (10 to < 40% miscarriage): intermediate-risk; scores 7–17 (≥ 40% miscarriage): high-risk.

Figure 3

ROC curve showing the performance of the preconception miscarriage risk score in predicting miscarriage. The area under the ROC curve was 0.74 (95% confidence interval 0.67, 0.81; p < 0.001). ROC receiver-operating-characteristic.