Premature birth: risks, complications, and baby care

A full-term pregnancy typically lasts between 37 and 42 weeks. But what happens when labor occurs early? Each year, approximately 15 million babies worldwide are born before the 37th week, which classifies them as premature.

Prematurity entails immaturity in vital organs and systems, which can seriously compromise their development. According to medical criteria, a baby born before the 28th week of gestation is considered extremely premature, and a baby born between the 29th and 31st week is considered very premature. “The limit of viability ranges between the 23rd and 24th week of gestation,” notes Dr. Ana Herranz, a neonatologist at Hospital Clínic Barcelona . She also points out that “of all children born prematurely, approximately 80% are born after the 32nd week.”

During pregnancy, there are signs that can alert you to the risk of premature delivery. These include bleeding between the second and third trimesters, loss of amniotic fluid—both possible symptoms of premature rupture of membranes—or the appearance of uterine contractions. If any of these signs occur, it is essential to see a doctor, who will perform a physical examination and may supplement the diagnosis with a vaginal ultrasound, a cardiotocographic record, or a blood test to rule out complications.

The limit of viability ranges between the 23rd and 24th week of gestation Dr. Ana Herranz, Neonatologist at the Hospital Clínic Barcelona

How is a premature baby stabilized?

After birth, the newborn spontaneously and naturally undergoes a series of vital changes related to lung function, blood circulation, and the digestive system, among others. In premature births, the neonatologist often requires interventions to stabilize the newborn.

Babies born before 34 weeks are usually transferred to the neonatal intensive care unit's incubator, where their body temperature is monitored and their cardiorespiratory vital signs are monitored. They also often require additional devices, such as feeding tubes, catheters, or infusion pumps for drug administration, as well as respiratory support systems.

What are the most common complications?

Despite receiving this care, premature babies face various risks. Among the most common complications are difficulties in lung development and maturation, growth retardation, and neurosensory, cognitive, and behavioral disorders. "The aspects that most concern neonatologists are those related to the lungs, nervous system, digestive system, and the risk of infection," explains Dr. Herranz.

Other possible complications include poor blood glucose control, anemia, yellowing of the skin due to elevated bilirubin levels, respiratory failure, bleeding in the brain, or damage to the white matter of the brain. Problems such as patent ductus arteriosus, sleep apnea, or severe intestinal inflammation may also occur.

The aspects that concern us most as neonatologists are those related to the lungs, the nervous system, the digestive system and the risk of infection. Dr. Ana Herranz, Neonatologist at the Hospital Clínic Barcelona

The most common infections in premature babies are sepsis, pneumonia, or meningitis, due to the immaturity of their defense mechanisms or the fact that they were born before the maternal immunoglobulin transfer is complete. Antibiotics are usually used to treat these infections.

Treatment for other complications may include supplemental oxygen or ventilatory assistance in the case of respiratory distress, specialized nutrition to promote proper growth—with breast milk being the most recommended food—or hemodynamic support when there are changes in heart rate or blood pressure. In some cases, the newborn may require admission to the Intensive Care Unit .

What are the risk factors?

Dr. Herranz explains that "in recent years, the trend toward prematurity has been increasing globally." This increase is mainly due to the rise of assisted reproduction techniques and the increasing maternal age. However, the main risk factors for premature birth are uterine factors—such as previous surgeries or malformations—complications during pregnancy, multiple pregnancies, an interval of less than six months between one birth and the next, tobacco or other toxic substance use, anxiety, and depression.

On the other hand, women who are underweight or, conversely, obese also have a higher risk of premature birth. Furthermore, women of African American or Afro-Caribbean origin are twice as likely to give birth prematurely compared to those of Caucasian origin. Having had a previous premature birth also significantly increases the chances of a repeat birth.

Although some risk factors cannot be avoided, there are recommendations to reduce the chances of premature birth. These include leaving at least 12 months between birth and a new pregnancy, quitting smoking and other harmful substances, correcting nutritional deficiencies and anemia, and ensuring adequate intake of omega-3 fatty acids and probiotics. In addition, some women with a history of prematurity can receive follow-up care in specialized units.

Prematurity remains one of the leading causes of infant mortality worldwide. The prognosis depends largely on the degree of prematurity: the earlier the birth and the lower the baby's weight, the greater the risk of complications. However, it is not possible to accurately predict the long-term clinical outcome based on these data alone.