Intrauterine Pregnancy Detection and Gestational Age Assessment During Early Pregnancy by a Handheld Point-Of-Care Ultrasound Device Compared to a High-End Ultrasound System. An Accuracy and Reliability Study.

Abstract

Objective: The main objective of this study is the evaluation of the accuracy and reliability of a handheld point of care ultrasound device (POCUS-hd) for intrauterine pregnancy (IUP) detection compared to comprehensive reference transabdominal ultrasound (TU). The secondary objectives were to evaluate POCUS-hd for intrauterine pregnancy (IUP) detection compared to transabdominal and transvaginal ultrasound (TUTV), evaluate the inter-device agreement and inter-rater reliability of gestational age during early pregnancy. Methods: It is an observational transverse study with consecutive patient recruitment. Two blinded operators systematically used POCUS-hd and reference transabdominal ultrasound for IUP diagnosis. The accuracy of POCUS-hd for IUP diagnosis was expressed as sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV). The gestational age (GA) was assessed based on the crown-rump length. The reliability and agreement of gestational age evaluation were assessed by Bland-Altman plots, kappa statistic, and intraclass correlation coefficients (ICC). Results: POCUS-hd compared to TU had a sensitivity of 95-100%, a specifcity of 90-100%, PPV of 95-100% and NPV of 90-100%. Inter-rater agreement for IUP detection using POCUS-hd was very good, kappa=1.0; CI95% [0.9-1.0]. The inter-device agreement limits (mean difference ± 2SD) for GA were: -3 to +2.3 days by Operator 1, -3.4 to +3.3 days by Operator 2 for POCUS-hd vs. TU and -3.1 to +2.3 days for POCUS-hd versus TUTV. Conclusion: This handheld POCUS device is an accurate and reliable diagnostic tool that can be used for IUP positive findings and GA assessment during early pregnancy by clinicians in family planning settings or general practice.