Why newborns need a vitamin K shot and eye ointment

In the first minutes after an uncomplicated birth at Sharp Mary Birch Hospital for Women & Newborns, a baby goes straight to their mother’s chest for skin-to-skin time. Only after that bonding time ends is the baby moved for further assessment.

First, the baby is moved to the warmer for a weight check and length and head measurements. Then, the baby receives two medications that have been routine for newborns for decades: a vitamin K injection and erythromycin eye ointment.

While the American Academy of Pediatrics (AAP) and the CDC recommend that all babies get a vitamin K shot and erythromycin eye ointment shortly after birth, parents often have questions about the role these medications play in protecting their baby’s health.

“Some parents ask us why their baby needs it,” says Dr. Jershonda Hartsfield, chief of pediatrics at Sharp Mary Birch and associate chair of the Department of Pediatrics at Sharp Rees-Stealy Medical Group. She explains what each medication does, why timing matters and what the experience is like for a newborn.

Why babies need vitamin K

Vitamin K helps blood clot normally, which prevents unnecessary bleeding. Adults get plenty from food and bacteria in the gut, but newborns start life with very little.

“Vitamin K is not transferred well from mother to baby,” Dr. Hartsfield says. “An adequate amount doesn’t transfer through the umbilical cord, or through the breast milk.”

Babies don't start producing enough vitamin K and eating foods rich in vitamin K until they're ready for solid foods, typically around 4 to 6 months of age. That leaves several months when their vitamin K levels remain low.

During that time, a baby’s blood doesn’t clot as well as it should. This can lead to extra bleeding after a circumcision or more bleeding than expected from a bump or scrape. The more serious risk is bleeding around the brain.

A brain bleed can begin without obvious warning signs. By the time a baby becomes unusually irritable, sleepy or difficult to wake, significant brain damage may already have occurred, Dr. Hartsfield says.

Why a shot instead of drops

According to Dr. Hartsfield, a shot is given because oral vitamin K is not very effective at preventing late-onset bleeding. Late-onset bleeding, also known as vitamin K deficiency bleeding (VKDB), occurs when a baby does not have enough vitamin K for their blood to clot properly. “That’s the type of bleeding the injection is especially effective at preventing,” she says.

The vitamin K used at Sharp Mary Birch is preservative-free, which she says can help ease a common concern for parents.

“There is a risk that your baby cries because they’re uncomfortable,” she says. “The brief discomfort must be weighed against the possibility of a serious bleed that could require hospitalization, IV treatment and days of care.”

Why every baby gets eye ointment

Another common medication newborns receive is eye ointment. Erythromycin ointment is an antibiotic applied once in a thin line on or inside each eyelid to prevent an eye infection that can be passed during birth. Left untreated, these infections can damage the cornea and cause permanent vision loss.

Dr. Hartsfield and the AAP recommend that all newborns receive the ointment, regardless of how they are delivered. Babies born to mothers without any known infection can still develop serious eye infections, including pink eye.

An infection can progress quickly, and early discharge can look like a blocked tear duct, making the infection easy to miss.

“One application at birth may spare a baby from more intensive treatment later,” Dr. Hartsfield says. “Treating an active infection can require IV or oral medication, plus an ointment several times a day for many days .”

The application itself is gentle. The ointment rests over the eyes and gradually spreads as the baby blinks. Because newborn vision is already somewhat blurry, the ointment doesn't meaningfully change what a baby sees. Any temporary blurring caused by the ointment usually clears within a few hours to a day, Dr. Hartsfield says.

Caring for your baby together

Both medications work best when given soon after birth, but they can still provide protection if administered later. If you have questions, talk with your pediatrician. “It is better that the treatments are administered sometime during your hospital stay,” Dr. Hartsfield says.

She understands the weight of the decisions that parents make in those first hours after welcoming a baby.

“As a parent myself, I always put myself in their shoes,” she says. “We are coming alongside parents to make sure we are providing the best care for their newborn as they are trying to do the very best for this little bundle of joy they just created.”

Learn more about pregnancy and newborn care at Sharp Mary Birch; get the latest health and wellness news, trends and patient stories from Sharp Health News.