Respiratory Distress Syndrome (RDS)

Neonatal respiratory distress syndrome (RDS), formerly known as hyaline membrane disease (HMD), is a breathing condition primarily seen in premature newborns. RDS occurs when the lungs don’t make enough surfactant, a substance that keeps the small air sacs in the lungs (alveoli) open.

Common signs of RDS include breathing difficulties such as:

• Chest retractions (when the muscles between the ribs cave in during breathing)
• Flaring nostrils
• Rapid breathing (tachypnea)
• Grunting sounds
• Blue or gray skin coloring, especially around the mouth (cyanosis)

Symptoms typically begin shortly after birth, peak two to three days later, then improve with treatment and as the lungs mature.

The main cause of RDS is underdeveloped lungs being unable to produce enough surfactant. Surfactant production usually begins between 24 and 28 weeks of pregnancy and reaches sufficient levels at about 35 weeks. While RDS is more common in premature infants, babies born full-term can also be at risk if there are conditions that interfere with how surfactant is made or functions, including:

• Gestational diabetes
• Cesarean delivery
• Infection
• Ingestion of meconium (feces) during delivery
• Problems with the placenta
• Lack of oxygen around the time of birth

RDS is more common in white infants, males, and those with a sibling who has had the condition. In rare cases, RDS is caused by a group of genetic conditions that affect surfactant production. These same genetic conditions may later be associated with interstitial lung disease (ILD).

At Boston Children’s, we use several tests to diagnose RDS, including:

• A physical exam to evaluate your baby’s overall appearance and how hard they’re working to breathe, which we check by looking for signs such as chest retractions, flaring nostrils, or grunting sounds
• Pulse oximetry to measure blood oxygen levels
• Chest X-rays, which can show a typical “ground glass” pattern seen in RDS
• Blood gases test to measure oxygen and carbon dioxide levels. In RDS, oxygen levels are often low, while carbon dioxide levels may be high. Additional tests can check for infections such as pneumonia, which can appear similar to RDS on an X-ray.
• Echocardiogram (ultrasound of the heart) to rule out problems that cause similar symptoms to RDS

Treatment for RDS may include:

• Supplemental oxygen through a nasal cannula, continuous positive airway pressure (CPAP, which is a small mask over the nose connected to a machine that helps keep the lungs open), or a ventilator
• Surfactant therapy (through a breathing tube) to help the lungs stay open
• Temperature support using a warmer or incubator
• Medication to manage pain, discomfort, or infection

Complications associated with RDS can include:

• Air leaks that occur when air sacs (alveoli) burst and travel air collects around the lungs or heart
• Pulmonary interstitial emphysema (PIE), which occurs when air escapes into the lung tissue, on X-ray this looks like bubbles of air
• Chronic lung disease, sometimes called bronchopulmonary dysplasia (BPD), which can develop when prolonged oxygen and ventilation to treat RDS results in damage to immature lungs

The best way to prevent RDS is to prevent a preterm birth whenever possible. When early delivery can’t be avoided, pregnant patients may receive corticosteroids before delivery, which can help speed up lung development and promote surfactant production.

Corticosteroids are most effective when given at least 24 hours before delivery. If labor progresses too quickly, there may not be enough time for the full benefit. However, even partial treatment can help reduce the severity of RDS.

At Boston Children’s Hospital, our Department of Newborn Medicine provides expert care for newborns with RDS and other conditions requiring critical medical attention in our Level IV Neonatal Intensive Care Unit (NICU).

Our team includes neonatologists, nurses, respiratory therapists, and other specialists who partner with families to provide personalized care that’s based on each baby’s unique needs. We also help coordinate continued support and follow-up care through our NICU Growth and Developmental Support (NICU GraDS) Program, which offers medical and developmental guidance as your child grows.