Definition

Oxygen is needed in every cell of the body. It first enters the body through the lungs. The oxygen is then picked up by the blood flowing by the lungs. The blood brings oxygen to the rest of the body. In newborns with persistent pulmonary hypertension (PPHN), the blood does not flow by the lungs.

The baby's lungs are not used during pregnancy. Instead, oxygen passes from the mother to the baby through the umbilical cord, bypassing the lungs. After the baby is born, the baby's lungs should take over. When this does not occur, most of the blood flow bypasses the lungs, does not pick up oxygen, and the body does not get enough oxygen.

PPHN can be a serious condition. It can cause both immediate and long-term health problems.

Circulatory System of Infant Copyright © Nucleus Medical Media, Inc.

Causes

PPHN can be caused by a variety of factors, including:

• An event or illness during pregnancy or childbirth, such as:
  • Meconium aspiration syndrome (the baby inhales meconium—the first stool—prior to or shortly after birth)
  • Severe pneumonia
  • Infection
  • Low blood sugar
  • Birth asphyxia (loss of oxygen to the fetus during delivery)
  • Respiratory distress syndrome —caused by lungs that have not fully developed
  • Use of nonsteroidal anti-inflammatory drugs (NSAIDs) by the mother during pregnancy
  • Late trimester maternal use of antidepressants, especially selective serotonin reuptake inhibitors (SSRIs)
  • Amniotic fluid leak
  • Low amniotic fluid— oligohydramnios
  • Abnormal lung development as a result of congenital diaphragmatic hernia or Potter syndrome
• Stress during pregnancy
• Isolated condition with an unknown cause

Risk Factors

Factors that may increase your baby’s chance of PPHN include:

• Stress to the fetus during pregnancy or delivery
• Health conditions of the mother, including diabetes
• Complications during birth or pregnancy

Symptoms

PPHN may cause:

• Rapid breathing—tachypnea
• Rapid heart rate— tachycardia
• Difficulty breathing—signs may include flared nostrils or grunting
• Blue tint to the skin, even when the baby is receiving oxygen

Diagnosis

You will be asked about your baby’s symptoms. Your pregnancy history may also be reviewed. A physical exam will be done.

Your baby's bodily fluids may be tested. This can be done with:

• Blood tests
• Pulse oximetry monitoring—continuous monitoring of oxygen levels in the blood

Images may be taken of your baby's bodily structures. This can be done with:

• Chest x-rays —to help diagnose lung disease or enlarged heart
• Echocardiogram —ultrasound of the heart to show the baby's circulating blood flow
• Head ultrasound —to look for bleeding in the brain

Treatment

Treatment for PPHN is typically given by a doctor who specializes in newborn illness.

Treatment begins with correcting any related conditions. These conditions can include low blood sugar, low oxygen levels, low blood pressure, and low blood pH. Treatment may include:

Prevention

Most cases of PPHN have no clear cause or are caused by uncontrollable events. For these cases there are no clear preventative steps. Some cases of PPHN may be prevented with proper prenatal care and good health of the mother during pregnancy. General tips for a healthy pregnancy include:

• Get good prenatal care. Start as early as possible in pregnancy.
• Eat a healthful diet and take recommended vitamins.
• Avoid smoking, drinking alcohol, and taking drugs.
• Only take medications that your doctor has approved.
• Avoid taking certain anti-inflammatory or antidepressant medication. Talk to your doctor about alternatives that may be safer.