Managing intrapartum fever: Ampicillin vs ampicillin and gentamicin | Image Credit: © Monstar Studio - © Monstar Studio - stock.adobe.com.
Intrapartum fever is associated with increased risks of maternal and neonatal complications, but a broad-range antibiotic can be considered for treatment, according to a recent study published in the American Journal of Obstetrics & Gynecology.
- Intrapartum fever is associated with increased risks of maternal and neonatal complications, including maternal infections, postpartum hemorrhage, stillbirth, premature birth, neurodevelopmental disabilities, and neonatal early-onset sepsis.
- Clinical chorioamnionitis is characterized by systemic inflammation in mothers or infants and is caused by intra-amniotic infection or sterile intra-amniotic inflammation. It is diagnosed based on at least 2 clinical signs and a maternal fever of 38 °C or more.
- Ampicillin and gentamicin are commonly used intrapartum antibiotics for managing clinical chorioamnionitis. However, there is no widely agreed-upon treatment for isolated intrapartum fever.
- A retrospective study compared outcomes of women with intrapartum fever treated with ampicillin versus those with clinical chorioamnionitis treated with ampicillin and gentamicin. Women with isolated intrapartum fever had higher rates of puerperal endometritis, while those with clinical chorioamnionitis had increased rates of cesarean delivery.
- Newborns of women with isolated intrapartum fever had increased rates of neonatal early-onset sepsis compared to those with clinical chorioamnionitis. However, other neonatal outcomes, such as NICU length of stay, Apgar score, ventilation support, and respiratory distress syndrome, were similar between the groups.
Clinical chorioamnionitis, presenting in 1% to 13% of all-term pregnancies and 20% to 70% of spontaneous preterm premature rupture of membranes (ROM), is characterized by systemic inflammation in mothers or infants and is caused by intra-amniotic infection or sterile intra-amniotic inflammation.
Complications of clinical chorioamnionitis include maternal infections, postpartum hemorrhage (PPH), stillbirth, premature birth, neurodevelopmental disabilities, and neonatal early-onset sepsis (EOS). At least 2 clinical signs, as well as a maternal fever of 38 °C or more, defines clinical chorioamnionitis.
Clinical signs defining clinical chorioamnionitis include maternal tachycardia, fetal tachycardia, maternal leukocytosis, purulent cervical discharge, and uterine tenderness. Ampicillin and gentamicin are intrapartum antibiotics commonly used to manage clinical chorioamnionitis. However, there is not a widely agreed treatment for isolated intrapartum fever.
Investigators conducted a retrospective study to compare obstetrical, neonatal, and microbiological outcomes after ampicillin treatment in women with intrapartum fever vs clinical chorioamnionitis treated with ampicillin plus gentamicin. Women admitted for delivery in an affiliated hospital from February 2011 to March 2020 were included in the analysis.
Eligibility criteria included a gestational age (GA) of 34 weeks or more and intrapartum fever development. Exclusion criteria included nonsustained fever, preterm birth, fetal malformation, intrauterine fetal death, other etiologies causing intrapartum fever, and penicillin allergy.
Intravenous ampicillin 2 g was administered 4 times a day to treat intrapartum fever, while ampicillin 2 g administered 4 times a day and gentamicin 240 mg daily were used to treat clinical chorioamnionitis. Extended antibiotic use was based on risk factors for puerperal endometritis.
Chorioamniotic membrane swabs, blood cultures, and antimicrobial susceptibility tests were performed, with an infectious disease specialist reviewing these analyses. Puerperal endometritis was the primary outcome of the analysis, defined by antibiotic administration in women with a fever of at least 38 degrees Celsiuswith no other cause and an associated clinical finding.
Secondary outcomes included maternal clinical outcomes, microbiological studies, neonatal intensive care unit (NICU) admission, 5-minute Apgar score below 7, length of NICU stay, required ventilation support, and respiratory distress syndrome (RDS).
There were 458 women included in the final analysis, 227 of whom had intrapartum fever treated with ampicillin and 231 had clinical chorioamnionitis treated with ampicillin and gentamicin. Of women with clinical chorioamnionitis, 100 were initially treated with ampicillin, with gentamicin added upon clinical chorioamnionitis diagnosis.
Women with isolated intrapartum fever had significantly higher rates of puerperal endometritis than those with clinical chorioamnionitis, at 8.8% and 3.9% respectively. However, rates of cesarean delivery in these groups were 31.2% and 65.4% respectively, showing a significant increase among women with clinical chorioamnionitis.
Newborns of women with isolated intrapartum fever had significantly increased rates of EOS compares to newborns of women with clinical chorioamnionitis, at 4.4% and 0.4% respectively. However, the median NICU length of stay, as well as the rates of antibiotic administration, 5-minute Apgar score below 7, required ventilation support, and RDS were similar between both groups.
Rates of positive chorioamniotic membrane swabs were 63.9% for women with isolated intrapartum fever and 46.2% for women with clinical chorioamnionitis. The most common pathogen observed in both groups through chorioamniotic membrane swabs was E coli, which was significantly more common in the isolated fever group than the clinical chorioamnionitis group.
These results indicatedampicillin treatment for intrapartum fever increased puerperal endometritis and neonatal EOS risks. Investigators concluded that since intrapartum fever may be a presentation of clinical chorioamnionitis, ampicillin and gentamicin should be considered for treatment.
Abu Shqara R, Glikman D, Jad S, et al. Antibiotic treatment of women with isolated intrapartum fever vs clinical chorioamnionitis: maternal and neonatal outcomes. Am J Obstet Gynecol. 2023;229:540.e1-9.doi:10.1016/j.ajog.2023.05.013