An observational study in Antenatal Care, Maternal Health and Gestational Age, sponsored by SOIK Corporation Sarl. Recruiting at 1 site in Democratic Republic of the Congo. Open to female participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-15.
Sponsored by SOIK Corporation Sarl · Observational
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.
Study conduct is organised in Batches. Batch 1 (Centre de Sante CBCO, Kenge health zone, Kwango province) enrolled 80 participants, of whom 78 had complete datasets, and is closed. Batch 2 is planned at approximately 1,300 participants. The confirmatory analysis cut is approximately 130 to 160 cases acquired with a model frozen before collection, comprising a core set of 80 to 100, an early-gestation enrichment of 25 to 30, and an upper-gestational-age enrichment of 25 to 30. Enrolment may stop early once the pre-specified confidence-interval criteria for the two primary gestational-age outcomes are met. The registered enrolment ceiling of 3,000 is unchanged.
Sites are facilities of the Kenge health zone, Kwango province, within the perimeter already approved in the protocol (up to 6 facilities plus 2 to 5 village outreach sites).
Eligibility follows the protocol: pregnant women aged 18 years or older. Multiple pregnancies are eligible.
Two sub-cohorts address the bounds of the gestational-age range. The early sub-cohort (crown-rump length 7 to 84 mm, approximately under 14 weeks) draws on the same source population as Cohort B-2 and is recruited through community health worker (RECO) village outreach and neighbouring health facilities; it is reported descriptively. The upper-bound sub-cohort (35 weeks or more) is a separate validation subset, recruited in parallel and analysed separately; sensitivity and specificity are reported, and positive and negative predictive values are not reported because prevalence in this subset is artificial.
The registered Trimester 3 estimation window (28 to 36 weeks) is unchanged. In Batch 2, point estimates are reported for 28 to 34 weeks, and 35 to 36 weeks is handled as "to be confirmed / refer". This is an operational reporting restriction, not a change to the registered window.
The AI model is identified and frozen before each Batch and recorded in a model and application version registry under a pre-determined change control plan. Results are reported by frozen version. AI inference is not used for clinical decision-making.
80 studies on the registry are indexed under Placenta Previa; 17 are open to participants now.
This study's planned enrollment of 3,000 is above the median of 100 across 32 observational studies indexed under Placenta Previa.
Browse Placenta Previa studies →This is the only study on the registry with SOIK Corporation Sarl as lead sponsor.
Counted across the registry records on this site, refreshed daily.
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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Natural enrollment / Description: Consecutive ANC attendees (natural prevalence)
Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound
Enriched validation subset for placenta praevia and fetal malpresentation
Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound
Enriched trimester 1 cases for CRL/GS gestational age models
Diagnostic Test: SPAQ E-con AI blind-sweep ultrasound
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
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
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.
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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: At Batch 1 closure, up to 8 weeks
Trimester 1 gestational age MAE (CRL and GS models)
Integrated Cohort A T1 + Cohort B-2, N=30; CRL model MAE ≤5 days or GS model MAE ≤7 days
Time frame: Through study completion, up to 12 months
Placenta praevia and fetal malpresentation sensitivity and specificity
Observed sensitivity/specificity with 95% CI (Clopper-Pearson) on enriched validation subset (Cohort B-1, target N=20-25); reported as observed values
Time frame: Through study completion, up to 12 months
Inter-rater reliability of gestational age - Intraclass Correlation Coefficient (ICC)
ICC(2,1) between two independent readers for gestational age in days
Time frame: During the inter-rater assessment window, up to 1 week
Inter-rater reliability of placenta praevia classification - Cohen's kappa
Cohen's kappa for placenta praevia (yes/no) between two independent readers
Time frame: During the inter-rater assessment window, up to 1 week
Inter-rater reliability of fetal presentation classification - weighted kappa
Linear weighted kappa for fetal presentation category between two independent readers
Time frame: During the inter-rater assessment window, up to 1 week
Acceptability - Acceptability of Intervention Measure (AIM) score
Mean AIM score (4-item, 5-point Likert) among health workers
Time frame: Through study completion, up to 12 months
Feasibility - ultrasound throughput (scans per device per day)
Number of scans completed per device per day; target \>=15
Time frame: Through study completion, up to 12 months
Fidelity - protocol adherence rate (5-item checklist)
Percentage adherence on a 5-item fidelity checklist; target \>=80%
Time frame: Through study completion, up to 12 months
Penetration - proportion of eligible women screened
Percentage of eligible women in the catchment screened with AI ultrasound
Time frame: Through study completion, up to 12 months
Sustainability - intention to continue use
Percentage of staff reporting intention to continue use at the end-of-study interview
Time frame: At study completion, up to 12 months
Plan to share: Undecided
No publications or documents are linked to this record.
Started Jun 2026 (actual). Primary completion is estimated for Dec 2026, 6 months after the start.
Of 15 observational studies under Placenta Previa, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 36. This study's planned 6 months is below that.
How these figures are worked out, and which studies are left out of them.
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