Vitamin K Shots for Newborns: Gender Disparity in Philadelphia Hospitals

Female newborns in Philadelphia are less likely to receive vitamin K shots than male newborns, according to a study published in JAMA Network Open on June 15, 2025. The research, conducted by the Children’s Hospital of Philadelphia, analyzed medical records of over 93,000 infants born between 2018 and 2025 across three University of Pennsylvania-affiliated hospitals.

Why Are Female Newborns Less Likely to Receive Vitamin K Shots?

The study found that 777 infants—two-thirds female—did not receive the vitamin K shot at birth. Among female infants, the refusal rate rose from 10 per 1,000 in 2018 to 20 per 1,000 in 2025. For males, the rate increased from 4 to 10 per 1,000. Researchers attribute this disparity to a policy at the hospitals: parents who refuse the vitamin K shot cannot have their sons circumcised. This link between circumcision and vitamin K administration appears to influence parental decisions, particularly for female infants.

What Are the Health Implications of Declining Vitamin K Rates?

Vitamin K is critical for preventing hemorrhagic disease of the newborn, a condition that can cause life-threatening internal bleeding. Newborns have low levels of the vitamin, as only minimal amounts pass from the mother to the fetus, and breast milk provides insufficient quantities. The American Academy of Pediatrics (AAP) has recommended universal vitamin K shots since 1961. However, refusal rates have risen nationwide due to misinformation about the shot’s safety and efficacy.

How Does This Study Compare to National Trends?

The study’s findings align with broader concerns about declining vaccine and preventive care rates among newborns. Researchers also noted a drop in hepatitis B vaccine administration at birth, with 83% of parents who declined vitamin K also refusing the hepatitis B shot. In May 2025, a federal judge temporarily halted proposed changes to the pediatric vaccine schedule, including the removal of the birth dose for hepatitis B. The AAP continues to advocate for this dose, emphasizing its role in preventing long-term liver disease.

What Strategies Could Address the Disparity?

The study’s authors suggest targeted efforts to improve vitamin K acceptance among parents of female infants. These could include educational campaigns highlighting the shot’s benefits and addressing misconceptions. Hospitals may also need to reevaluate policies that tie procedures like circumcision to vitamin K administration, as such practices could inadvertently contribute to health disparities.

The findings underscore the importance of equitable access to newborn care and the need for transparent communication between healthcare providers and families. As vaccination rates remain under scrutiny, addressing barriers to essential treatments like vitamin K shots is critical for protecting infant health.