Artificial Intelligence Causal Inference of Community Clinic Antenatal Corticosteroid Timing Under Unmeasured Gestational Dating Ultrasound Unavailability: A Healthcare Instrumental Variable Neonatal Outcome Evaluation

Community clinics frequently administer antenatal corticosteroids without ultrasound-based gestational dating, so the timing of treatment relative to true gestational age is measured with error that is neither classical nor ignorable. The framework is evaluated through a replication-based design study of the before-after-control-impact estimator under a declared variance structure (between-cluster SD = 6.0, residual SD = 4.5, intraclass correlation = 0.64). Power was estimated across 2000 design cells for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points.52 clusters are required to detect a 5-percentage-point effect at 80% power, and that the minimum detectable effect falls steeply as cluster count rises from 8 to 32. The contribution is a design-theoretic account of when instrumental-variable causal inference can recover corticosteroid-timing effects from community clinic records that lack dating ultrasound, together with the sample-size conditions under which such inference is credible.