Persistent pulmonary hypertension of the newborn (PPHN) can occur in babies when the circulatory system does not adapt to conditions outside the mother’s uterus. Before birth, the baby’s oxygen needs are met through the placenta in the mother’s uterus. After birth, the baby’s lungs take over this function. After being born, the baby inflates its lungs with its first breaths. Then, a series of changes take place to decrease resistance to blood flowing through the newborn’s lungs. This allows the lungs to take over getting oxygen for the baby’s vital functions.
Sometimes, the changes that allow blood to preferentially flow from the baby’s heart to the lungs do not proceed normally, or at all. This can occur in approximately 2 out of 1000 births.
Some PPHN cases are due to problems in the baby’s lung tissue. For example, if a baby has damaged lungs from inhaling meconium, or pulmonary damage from prematurity, this can contribute to pulmonary hypertension. Development problems or defects in lung and related blood vessels can also lead to PPHN. However, PPHN can develop even when the lung tissue and blood vessels are normal.
Some cases of persistent pulmonary hypertension of the newborn have been linked to medications used by pregnant women. Antidepressants such as Zoloft (sertraline), Paxil (paroxetine), Prozac (fluoxetine), Lexapro (escitalopram) and Celexa (citalopram) may be associated with PPHN. The FDA issued a public health advisory in 2006 about the use of these medications in pregnant women.
It is crucial for pregnant women to review their medical and medication histories with their doctors. Certain medications may need to be adjusted, stopped, or continued according to the patient’s needs and risks to the unborn baby. If potentially damaging medications were used and a birth defect such as PPHN occurred, the victims may have legal rights that need to be protected.