If Goldilocks Had a Baby

Babies born right on time fared better than those born at full term but slightly early

(RxWiki News) By the time a mother's due date nears, she's often more than ready to meet her child and lose the big tummy. But an extra week or two at term may be a good thing.

A recent study found that babies born at full term, but just a little on the early side, may experience higher risks for complications.

A full-term baby is typically considered one born from 37 to 41 weeks. A premature baby is typically one born before 37 weeks.

However, within that full-term range, babies born at 37 and 38 weeks are considered early-term births: they are born on the "early" side of "on time."

These babies had slightly higher rates of admission to the NICU and higher rates for needing certain interventions after birth.

"Attend all prenatal appointments."

This study, led by Shaon Sengupta, MD, MPH, of the Division of Neonatology at Children's Hospital of Philadelphia, looked at the outcomes of babies born at 37 and 38 weeks.

The researchers examined the records of 29,664 live births that occurred in the three-year period from January 2006 and December 2008 in Erie County, New York.

Of these, 27 percent (9,031 babies) were born early term, during the 37th or 38th week of pregnancy.

The researchers compared the risks found among these babies with the babies born during the 39th, 40th or 41st week of pregnancy.

The results revealed some higher risks for the babies born in the 37th and 38th weeks.

While 4.9 percent of early-term babies had hypoglycemia (abnormally low blood sugar levels), only 2.5 percent of babies born at term (39th-41st weeks) had hypoglycemia.

About 8.8 percent of early-term babies were admitted to the neonatal intensive care unit or a neonatology unit, compared to 5.3 percent of the babies born between the 39th and 41st weeks of pregnancy.

Twice as many babies needed respiratory support if they were born early-term: 2 percent of those born at 37 and 38 weeks needed respiratory support, compared to 1.1 percent of those born later.

About 7.5 percent of babies born at 37 and 38 weeks needed intravenous fluids after birth, compared to 4.4 percent of those born between 39 and 41 weeks.

Similarly, 2.6 percent of babies born at 37 and 38 weeks required treatment with intravenous antibiotics, compared to 1.6 percent of babies born at full term.

Finally, 0.6 percent of babies born at 37 and 38 weeks needed mechanical ventilation or intubation (mechanical help for breathing), compared to 0.1 percent of babies born between 39 and 41 weeks.

The researchers also found that cesarean deliveries were more common among early-term births than among full-term births.

While 38 percent of babies born at 37 and 38 weeks were born by C-section, 29 percent of babies born between 39 and 41 weeks were born by C-section.

Among the babies born by C-section, 52 percent of the babies born at 37 and 38 weeks required admission to the NICU, compared to 42 percent of babies born between 39 and 41 weeks.

The researchers therefore concluded that babies born at term but on the early side may be at higher risk for various complications after birth.

The study was published September 30 in the journal JAMA Pediatrics. The authors declared no conflicts of interest.

The research was funded by the Division of Neonatology at the University of Buffalo, an American Academy of Pediatrics Resident Research Grant and the Thomas F. Frawley, MD, Residency Research Fellowship Fund at the University of Buffalo.

Review Date: 
September 30, 2013