Rising rate of non-receipt of vitamin K prophylaxis for newborns, January 2019 - June 2026

Background: Vitamin K prophylaxis is universally recommended for newborns to prevent life threatening vitamin K deficiency bleeding. Although not on the immunization schedule, vitamin K prophylaxis is often coadministered with hepatitis B birth dose and erythromycin ophthalmic ointment, and rising hesitancy around vaccines/preventive care may spill over into vitamin K administration. Methods: We conducted a retrospective cohort study using Truveta electronic health record data with linked mother-child dyads. Live births to mothers aged 15-49 from January 1, 2019 through June 30, 2026 were included. Vitamin K administration was defined as documentation on the birth date or following day. Logistic regression assessed sociodemographic predictors of non-receipt, and interrupted time series analysis evaluated changes after January 2026. Results: Among 1,026,375 infants, 995,628 (96.97%) had documented vitamin K administration. Non-receipt increased from an average of 2.1% during 2019-2022 to 4.3% in 2025 and 6.1% in 2026, reaching 8.10% in June 2026. Older maternal age, non-Hispanic or Latino ethnicity, Medicaid or unknown insurance, and year of delivery were associated with greater odds of non-receipt. After January 2026, there was no immediate step change, but the odds of vitamin K receipt declined an additional 10% per month (OR: 0.90; 95% CI, 0.88-0.91). Conclusions: Vitamin K non-receipt increased over the study period and accelerated after January 2026. Because vitamin K recommendations were not changed by the January vaccine schedule, this association may reflect broader impacts to confidence in newborn preventive care. Future studies should examine causal mechanisms, parental decision-making, and associated clinical outcomes.