The first hour after birth is often an important time for skin-to-skin contact, bonding, and the first feeding. When the birth parent and baby are stable, many routine newborn procedures can be completed without separating them or can wait until after this initial time together.¹

One routine newborn treatment is erythromycin eye ointment. In the NICU, we often call two early newborn medications “eyes and thighs”: erythromycin ointment for the eyes and a vitamin K injection in the thigh.^19,20 The ointment is placed in both eyes to help prevent gonococcal ophthalmia neonatorum, a rare but serious infection that can cause permanent eye damage or blindness.^5,17

Many parents are surprised when this medication is offered shortly after birth, especially after a healthy pregnancy. Understanding why it is recommended can help you feel more prepared for your baby’s first hours.

Related: Vitamin K Shot for Newborns: Benefits, Risks, & What To Know

What Is Erythromycin Eye Ointment?

Erythromycin is a macrolide antibiotic. For newborn eye prophylaxis, a 0.5% ophthalmic ointment is placed inside each lower eyelid to help prevent ophthalmia neonatorum caused by the bacterium Neisseria gonorrhoeae.^5,17,20

This routine application is preventive. It is not sufficient treatment for a newborn who already has a suspected or confirmed gonococcal infection. Those babies need systemic antibiotics because topical ointment alone is inadequate.¹⁰

Related: The First 24 Hours of Baby’s Life: What To Expect

What Is Ophthalmia Neonatorum?

Ophthalmia neonatorum, also called neonatal conjunctivitis, is conjunctivitis that develops during a baby’s first month of life. It can have several causes, including gonorrhea, chlamydia, other bacteria, viruses, and chemical irritation. Erythromycin eye ointment is recommended primarily to help prevent gonococcal ophthalmia because this infection can progress rapidly and cause severe eye damage if left untreated.^5,7

Gonococcal ophthalmia usually develops two to five days after birth. Symptoms may include eye redness, significant eyelid swelling, and thick or pus-like discharge. Without prompt systemic treatment, the infection can cause corneal scarring, ocular perforation, and blindness. In severe cases, it may also spread through the bloodstream and lead to complications such as sepsis, arthritis, or meningitis.^5,8,9,10

Chlamydial conjunctivitis usually develops five to 12 days after birth. Unlike gonococcal disease, erythromycin eye ointment does not reliably prevent chlamydial conjunctivitis or chlamydial pneumonia. Prenatal screening and treatment during pregnancy remain the most effective ways to reduce those infections.^7,11

Related: Pink Eye Treatment for Kids

When Do Newborns Receive Erythromycin Eye Ointment?

Because gonococcal eye infections can develop quickly after birth, erythromycin eye ointment is usually applied shortly after delivery. The CDC recommends placing the ointment in both eyes as soon as possible after birth, regardless of whether the baby was born vaginally or by Cesarean birth. If administration is delayed, hospitals should have a system to ensure newborns receive it within 24 hours.^9,10

For healthy newborns, many hospitals coordinate routine newborn medications with skin-to-skin contact, the first feeding, and other early newborn care. If you have questions about when your baby will receive erythromycin ointment, ask your healthcare team how it fits into your hospital’s routine.²¹

What Is in Erythromycin Eye Ointment?

Each gram of erythromycin ophthalmic ointment contains 5 milligrams (0.5%) of erythromycin as the active ingredient. The ointment is made with a sterile base of mineral oil and white petrolatum, which help it stay in contact with the baby’s eyes long enough for the medication to work.^12,13,14

Possible Side Effects of Erythromycin Eye Ointment

Erythromycin eye ointment is generally well tolerated by newborns. The most commonly reported side effects are mild eye irritation, temporary redness, and rare hypersensitivity (allergic) reactions.¹⁵

Because the ointment is thick, your baby’s eyes may temporarily look greasy or cloudy after it is applied. This temporary appearance is expected and usually clears as the ointment is absorbed. Contact your baby’s healthcare provider if eye redness, swelling, irritation, or discharge is severe, gets worse, or does not improve.^15,16

Like all antibiotics, erythromycin should be used thoughtfully. Researchers continue to monitor antibiotic resistance, but current evidence shows that the benefits of routine newborn eye prophylaxis against serious gonococcal eye infection outweigh the known risks.^5,17

Why Is Erythromycin Recommended for All Newborns?

The U.S. Preventive Services Task Force (USPSTF) recommends routine erythromycin eye ointment for all newborns, and the Centers for Disease Control and Prevention (CDC) identifies 0.5% erythromycin ophthalmic ointment as the recommended regimen in the United States.^5,17 Universal newborn eye prophylaxis is recommended because gonorrhea often causes no symptoms during pregnancy, not every pregnant person receives adequate prenatal care or screening, and infection can be acquired after an earlier negative test.

This recommendation applies to all newborns, including babies born vaginally and by Cesarean birth.^5,10

Can Parents Decline Erythromycin Eye Ointment?

Erythromycin eye ointment is considered standard newborn care in the United States and is required by law in most states. The exact requirements and options for declining treatment vary by state, hospital, and birth setting.^5,17

If you are considering declining erythromycin eye ointment, discuss it with your OB/GYN, pediatrician, or birth team before delivery. When refusal is permitted, parents may be asked to sign documentation confirming that they understand the potential risks.⁵

Are There Alternatives to Erythromycin Eye Ointment?

Prenatal screening and treatment are the best ways to reduce the chance of a baby being exposed to gonorrhea during delivery. Current CDC guidance recommends gonorrhea screening for all pregnant women younger than 25 and for pregnant women 25 and older who have increased risk factors.¹⁸

Even so, prenatal screening does not replace routine newborn eye prophylaxis in the United States. Some pregnant people receive limited or no prenatal care, gonorrhea often causes no symptoms, and infection can still be acquired after an earlier negative screening test.^5,17

No other eye medication is currently recommended as a substitute for erythromycin ointment in the United States. Silver nitrate and tetracycline ophthalmic ointments are no longer available, bacitracin is ineffective, povidone-iodine has not been studied adequately, and gentamicin ophthalmic ointment has been associated with severe eye reactions.¹⁸

If erythromycin is unavailable, the CDC recommends systemic ceftriaxone for newborns at increased risk of gonococcal exposure, such as babies born to mothers with untreated gonorrhea or when maternal infection cannot be ruled out.¹⁸

Final Thoughts for Parents

Erythromycin eye ointment is a low-risk and effective way to help prevent gonococcal ophthalmia neonatorum, a rare but serious infection that can cause permanent eye damage or blindness if left untreated.^5,17 Its recommendation for all newborns reflects the fact that gonorrhea often causes no symptoms during pregnancy and that prenatal screening cannot prevent every possible exposure.

If you have questions about when erythromycin eye ointment is given, its possible side effects, your state’s requirements, or whether it is right for your baby, talk with your OB/GYN, pediatrician, or birth team before delivery. Understanding why it is recommended can help you have informed conversations with your healthcare team and feel more prepared for your baby’s care after birth.