Low-risk Preterm Infants May Not Need Antibiotics

Jake Remaly

May 17, 2021

Selective use of antibiotics based on birth circumstances may reduce unnecessary antibiotic exposure for preterm infants at risk of early-onset sepsis, based on data from 340 preterm infants at a single center.

Preterm infants born because of preterm labor, premature rupture of membranes, and/or intraamniotic infection (IAI) are considered at increased risk for early-onset sepsis, and current management strategies include a blood culture and initiation of empirical antibiotics, said Kirtan Patel, MD, of Texas A&M University, Dallas, and colleagues in a poster (# 1720) presented at the Pediatric Academic Societies annual meeting.

However, this blanket approach "may increase the unnecessary early antibiotic exposure in preterm infants possibly leading to future adverse health outcomes," and physicians are advised to review the risks and benefits, Patel said.

Data from previous studies suggest that preterm infants born as a result of preterm labor and/or premature rupture of membranes with adequate Group B Streptococcus (GBS) intrapartum antibiotic prophylaxis and no indication of IAI may be managed without empiric antibiotics because the early-onset sepsis risk in these infants is much lower than the ones born through IAI and inadequate GBS intrapartum antibiotic prophylaxis.

To better identify preterm birth circumstances in which antibiotics might be avoided, the researchers conducted a retrospective cohort study of preterm infants born at 28-34 weeks' gestation during the period from Jan. 1, 2015, to Dec. 31, 2018. These infants were in the low-risk category of preterm birth because of preterm labor or premature rupture of membranes, with no IAI and adequate GBS intrapartum antibiotic prophylaxis, and no signs of cardiovascular or respiratory instability after birth. Of these, 157 (46.2%) received empiric antibiotics soon after birth and 183 infants (53.8%) did not receive empiric antibiotics.

The mean gestational age and birth weight were significantly lower in the empiric antibiotic group, but after correcting for these variables, the factors with the greatest influence on the initiation of antibiotics were maternal intrapartum antibiotic prophylaxis (odds ratio, 3.13); premature rupture of membranes (OR, 3.75); use of continuous positive airway pressure (CPAP) in the delivery room (OR, 1.84); CPAP on admission to the neonatal intensive care unit (OR, 1.94); drawing a blood culture (OR, 13.72); and a complete blood count with immature to total neutrophil ratio greater than 0.2 (OR, 3.84).

Three infants (2%) in the antibiotics group had culture-positive early-onset sepsis with Escherichia coli, compared with no infants in the no-antibiotics group. No differences in short-term hospital outcomes appeared between the two groups. The study was limited in part by the retrospective design and sample size, the researchers noted.

However, the results support a selective approach to antibiotics for preterm infants, taking various birth circumstances into account, they said.

Further Risk Factor Identification Could Curb Antibiotic Use

In this study, empiric antibiotics were cast as a wide net to avoid missing serious infections in a few patients, said Tim Joos, MD, a Seattle-based clinician with a combination internal medicine/pediatrics practice, in an interview.

"It is interesting in this retrospective review of 340 preterm infants that the three newborns that did have serious bacterial infection were correctly given empiric antibiotics from the start," Joos noted. "The authors were very effective at elucidating the possible factors that go into starting or not starting empiric antibiotics, although there may be other factors in the clinician's judgment that are being missed. … More studies are needed on this topic," Joos said. "Further research examining how the septic newborns differ from the nonseptic ones could help to even further narrow the use of empiric antibiotics," he added.

The study received no outside funding. The researchers had no financial conflicts to disclose. Joos had no financial conflicts to disclose, but serves as a member of the Pediatric News Editorial Advisory Board.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


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