Trends in Vitamin K Administration Among Infants

Abstract

This study evaluates whether the proportion of newborns in the US not receiving intramuscular vitamin K has increased in recent years and identifies factors associated with nonreceipt.

Routine newborn intramuscular vitamin K prophylaxis has nearly eliminated vitamin K deficiency bleeding in the US since initiation of universal administration in 1961.¹ Nonetheless, there are reports of increasing parental vitamin K refusal and resultant bleeding.² To mitigate risk of such bleeding, newborns require prophylaxis at birth because of minimal vitamin K placental transfer, poor gastrointestinal absorption, and low concentrations in breast milk. Parents sometimes refuse newborn vitamin K administration because of concerns regarding necessity, injection pain, and potential adverse effects.^1,2,3 Public skepticism regarding pediatric preventive interventions has grown after the COVID-19 pandemic.⁴ Whether national rates of intramuscular vitamin K administration have changed in this period is unknown. This study aimed to evaluate whether the proportion of newborns not receiving intramuscular vitamin K has increased in recent years and identify factors associated with nonreceipt.

Methods

We performed a retrospective cohort study of newborns in Epic Systems’ Cosmos research platform (January 2017 to December 2024), a US-based electronic health record database with anonymized, deidentified, patient-level data. Hospitals with at least 10 births per year in every year of the study period and newborns of 35 to 43 weeks’ gestation were included; 403 hospitals across all 50 states and the District of Columbia contributed data. After calculating the proportion of newborns not receiving intramuscular vitamin K, we examined associated maternal and newborn characteristics as well as changes in characteristics over time, with a standardized difference greater than 0.1 considered significant (eAppendix in Supplement 1). Race and ethnicity data were obtained from electronic medical records; prior studies have reported differences in vitamin K administration by race.⁵ Adjusted percentages of newborns not receiving vitamin K over time were calculated using a logistic regression model adjusted for covariates associated with vitamin K administration in bivariate analysis (eAppendix in Supplement 1). The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cohort studies was followed. The Children’s Hospital of Philadelphia Institutional Review Board deemed this study to be non–human subjects research.

Results

Of 5 096 633 newborns, 199 571 (3.92%) did not receive intramuscular vitamin K, which increased from 2.92% (15 354/526 341) in 2017 to 5.18% (37 187/717 402) in 2024 (unadjusted P < .001 for trend) (Figure and Table). No maternal or infant characteristics changed significantly over time. Race and ethnicity, with highest rates among non-Hispanic White and other or unknown populations, and vaginal birth were associated with not receiving vitamin K (Table). Multivariable-adjusted percentages of newborns not receiving vitamin K also increased throughout the study period, from 2.57% (95% CI, 2.52%-2.63%) in 2017 to 4.62% (95% CI, 4.55%-4.70%) in 2024.

Figure. Percentage of Newborns Not Receiving Prophylactic Intramuscular Vitamin K Administration After Birth.

Overall, 199 571 of 5 096 633 (3.92%) did not receive vitamin K. The results demonstrated a linear trend via χ² test (P < .001).

Table. Characteristics Among Infants of 35 to 43 Weeks’ Gestation Who Did and Did Not Receive Routine, Prophylactic, Intramuscular Vitamin K in Epic Cosmos, January 2017 to December 2024 (N = 5 096 633).

Characteristics	No. (%)		Standardized differencea
	Vitamin K received	Vitamin K not received
Maternal characteristics
Total	4 897 062 (96.1)	199 571 (3.92)
Age, y
<20	152 543 (96.7)	5137 (3.3)	0.05
20 to <35	3 681 004 (96.1)	147 474 (3.9)
≥35	1 063 502 (95.8)	46 958 (4.2)
Race and ethnicity
American Indian or Alaska Native	50 528 (96.3)	1936 (3.7)	0.14a
Asian	300 536 (96.3)	11 469 (3.7)
Non-Hispanic Black	835 719 (96.6)	28 977 (3.4)
Hispanic	897 989 (96.7)	30 484 (3.3)
Native Hawaiian or Other Pacific Islander	29 753 (97.4)	799 (2.6)
Non-Hispanic White	2 641 985 (95.7)	117 604 (4.3)
Other or unknownb	140 552 (94.4)	8302 (5.6)
Infant’s insurance
Public	1 940 239 (96.2)	75 762 (3.8)	0.03
Otherc	2 956 823 (96.0)	123 809 (4.0)
Social Vulnerability Indexd
High risk	1 617 137 (96.4)	61 238 (3.6)	0.04
Low risk	3 279 925 (96.0)	138 333 (4.0)
Residencee
Urban	4 246 452 (96.0)	174 652 (4.0)	0.05
Rural	577 904 (96.2)	23 046 (3.8)
Mode of delivery
Vaginal	3 352 096 (95.8)	148 589 (4.2)	0.14a
Cesarean	1 544 966 (96.8)	50 982 (3.2)
Infant characteristics
Birth weight, mean (SD), g	3312 (492)	3342 (506)	0.06
Sex
Female	2 396 209 (95.9)	102 066 (4.1)	0.04
Male	2 500 853 (96.2)	97 505 (3.8)

^a Dissimilarities were quantified between groups using standardized differences. A standardized difference >0.1 indicates substantial imbalance between groups (see the eAppendix in Supplement 1 for details).

^b Other includes missing or unspecified race and ethnicity.

^c Other includes private, Tricare (military), and unspecified insurance.

^d The Centers for Disease Control and Prevention Social Vulnerability Index is quantified at the census tract level; high risk and low risk are the top and bottom 3 quartiles of values across the cohort, respectively.

^e Residence was determined using maternal zip codes, which were grouped into urban or rural using Rural-Urban Commuting Area codes (codes 1-3 considered urban and 4-10 considered rural), which were missing for 0.01% of the cohort.

Discussion

The proportion of newborns not receiving intramuscular vitamin K increased from 2.92% to 5.18% in a large US-based electronic health record dataset from 2017 to 2024. These rates are consistent with a 2016 North Carolina study of more than 18 000 newborns but higher than in a 2018 study of 102 878 newborns across 34 states (0.6%).^3,5 Changes in vitamin K administration rates may not have resulted solely from COVID-19–related public skepticism of pediatric medical interventions, as the increase in infants not receiving vitamin K subtly began prior to the pandemic’s 2020 onset. While refusal is likely the major contributor to not receiving vitamin K,⁶ this study lacked data from parents or clinicians on the reasons for nonreceipt. These findings are generalizable only to infants of at least 35 weeks’ gestation. Vitamin K administration in out-of-hospital birth was not captured in this analysis; thus, the observed rates of nonreceipt may be an underestimate because vitamin K refusal rates are higher for planned home births.¹ Further study is warranted to evaluate whether these trends are associated with increased risk of major bleeding such as intracranial hemorrhage. A multipronged approach composed of interventions including public health regulation at the state level and standardized practice regarding clinician communication with patients regarding vitamin K refusal at the hospital level is urgently needed to improve rates of highly effective prophylactic intramuscular vitamin K administration to prevent bleeding and its associated morbidity and mortality.

Supplement 1.

eAppendix. Supplemental Methods

eReferences

Supplement 2.

Data Sharing Statement