AI Blind-Sweep Ultrasound for Antenatal Screening by Non-Specialist Health Workers in Rural DR Congo

NCT07677670 | Recruiting

• 1 other identifier: SOIK-FS2-2026
• Study Type: observational
• Target: 3,000
• Locations: 1 country
• Sites: 1

Brief Summary

FS2 evaluates the diagnostic accuracy and implementation feasibility of an AI-assisted blind-sweep obstetric ultrasound (SPAQ E-con AI), operated by trained non-specialist health workers, for antenatal screening in rural Democratic Republic of the Congo. Primary outcomes are gestational age mean absolute error (Trimester 2 and Trimester 3) with 95% confidence intervals and AI confidence calibration. The reference standard is manual measurement by a reference reader (early ultrasound first; manual BPD if unavailable; last menstrual period is not used). Planned enrollment is approximately 1,380: Batch 1 (closed, 80 enrolled) and Batch 2 (approximately 1,300), within an IRB-approved ceiling of 3,000. Early termination is permitted upon achievement of pre-specified analysis-plan thresholds. The study is a multi-center prospective Hybrid Type 1 Effectiveness-Implementation design and includes a pre-specified adaptive model-update (Batch 2 cut) plan following FDA PCCP and STARD-AI guidance.

Conditions

Antenatal Care; Maternal Health; Gestational Age; Placenta Praevia; Diagnostic Imaging

Keywords

blind sweep ultrasound; artificial intelligence; point-of-care ultrasound; task-shifting; DRC

Outcome Measures

Primary Outcomes (4)

• Gestational age mean absolute error (MAE), Trimester 2 (14-27 weeks)

  MAE in days vs reference standard, with 95% CI; target MAE ≤7 days and upper 95% CI ≤10 days

  Through study completion, up to 12 months

• Gestational age mean absolute error (MAE), Trimester 3 (28-36 weeks)

  MAE in days vs reference standard, with 95% CI; target MAE ≤10 days and upper 95% CI ≤14 days

  Through study completion, up to 12 months

• AI confidence calibration - Expected Calibration Error (ECE)

  Expected Calibration Error from the reliability diagram of AI confidence versus reference-standard agreement; target \<=0.05

  At Batch 1 closure, up to 8 weeks

• AI confidence calibration - Brier score

  Brier score of AI confidence versus reference-standard agreement; target \<=0.20

  At Batch 1 closure, up to 8 weeks

Secondary Outcomes (10)

• Trimester 1 gestational age MAE (CRL and GS models)

  Through study completion, up to 12 months

• Placenta praevia and fetal malpresentation sensitivity and specificity

  Through study completion, up to 12 months

• Inter-rater reliability of gestational age - Intraclass Correlation Coefficient (ICC)

  During the inter-rater assessment window, up to 1 week

• Inter-rater reliability of placenta praevia classification - Cohen's kappa

  During the inter-rater assessment window, up to 1 week

• Inter-rater reliability of fetal presentation classification - weighted kappa

  During the inter-rater assessment window, up to 1 week

Study Arms (5)

Cohort A

Natural enrollment / Description: Consecutive ANC attendees (natural prevalence)

Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound

Cohort B-1 Placenta/malpresentation enriched

Enriched validation subset for placenta praevia and fetal malpresentation

Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound

Cohort B-2 - Trimester 1 (CRL/GS) enriched

Enriched trimester 1 cases for CRL/GS gestational age models

Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound

Cohort B-3 - Early gestation (CRL 7-84 mm) enriched

Early-gestation enrichment sub-cohort: crown-rump length 7-84 mm, approximately under 14 weeks of gestation. Drawn from the same source population as Cohort B-2 and recruited through community health worker (RECO) village outreach and neighbouring health facilities. Reported descriptively.

Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound

Cohort B-4 - Upper gestational-age bound (>=35 weeks) validation subset

Validation subset at the upper bound of the gestational-age range (35 weeks of gestation or more), recruited in parallel with the main cohort and analysed separately. Sensitivity and specificity are reported. Positive and negative predictive values are not reported, because prevalence in this subset is artificial.

Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound

Interventions

SPAQ E-con AI blind-sweep ultrasound DIAGNOSTIC_TEST

Smartphone-based 9-sweep obstetric ultrasound with AI estimation of gestational age, fetal presentation, and placenta location, operated by trained non-specialist health workers after 30-60 minutes of training. The AI model is frozen before each Batch and managed in a version registry under a pre-determined change control plan (PCCP); AI inference is not used for clinical decision-making.

Cohort A; Cohort B-1 Placenta/malpresentation enriched; Cohort B-2 - Trimester 1 (CRL/GS) enriched; Cohort B-3 - Early gestation (CRL 7-84 mm) enriched; Cohort B-4 - Upper gestational-age bound (>=35 weeks) validation subset

Eligibility Criteria

• Age: 18 Years+
• Gender Eligibility Details: Female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Pregnant women attending routine antenatal care at participating facilities or identified through community health worker (RECO) village outreach in the Kenge health zone, Kwango province, DRC.

You may qualify if:

• Pregnant women aged 18 years or older
• Identified at a participating facility routine ANC visit or RECO village outreach within the Kenge health zone catchment
• Written informed consent obtained

You may not qualify if:

• Emergency presentation
• Duplicate re-registration of an already-enrolled woman
• Lacking capacity to consent
• Planned relocation outside Kwango province during the study period
• Refusal of consent

Sponsors & Collaborators

• SOIK Corporation Sarl: lead

Study Sites (1)

Centre de Sante CBCO

Kenge, Kwango, Democratic Republic of the Congo

RECRUITING

MeSH Terms

Conditions

Placenta Previa

Condition Hierarchy (Ancestors)

Obstetric Labor Complications; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Placenta Diseases

Study Officials

• Kuniyuki Furuta

  SOIK Corporation

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Kuniyuki Furuta

CONTACT

+818099740409; furuta@soik.co.jp

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 18, 2026
• First Posted: July 1, 2026
• Study Start: June 19, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): June 13, 2027
• Last Updated: September 15, 2026

Record last verified: 2026-09

Locations

DE (1)