Predictive performance for placental dysfunction related stillbirth of the competing risks model for small‐for‐gestational‐age fetuses

Objectives:

To examine the predictive performance for placental dysfunction related stillbirths of the competing risks model for small-for-gestational-age (SGA) fetuses based on fetusa combination of maternal risk factors, estimated fetal weight (EFW) and uterine artery pulsatility index (UtA-PI); and second, to compare the performance of this model with that of a stillbirth-specific model using the same biomarkers and with the Royal College of Obstetricians and Gynecologists (RCOG) guideline for the investigation and management of the SGA fetus.

Design:


Prospective observational study.

Setting:


Two UK maternity hospitals.

Population:

A total of 131 514 women with singleton pregnancies attending for routine ultrasound examination at 19-24 weeks of gestation.

Methods:

The predictive performance for stillbirth achieved by three models was compared.

Main outcome measure:

Placental dysfunction related stillbirth.

Results:

At 10% false-positive rate, the competing risks model predicted 59%, 66% and 71% of placental dysfunction related stillbirths, at any gestation, at <37 weeks and at <32 weeks, respectively, which were similar to the respective figures of 62%, 70% and 73% for the stillbirth-specific model. At a screen positive rate of 21.8%, as defined by the RCOG guideline, the competing risks model predicted 71%, 76% and 79% of placental dysfunction related stillbirths at any gestation, at <37 weeks and at <32 weeks, respectively, and the respective figures for the RCOG guideline were 40%, 44% and 42%.

Conclusion:

The predictive performance for placental dysfunction related stillbirths by the competing risks model for SGA was similar to that of the stillbirth-specific model and superior to that of the RCOG guideline.