Teresa Carr

Antibiotic use in pregnancy and drug-resistant infant sepsis

OBJECTIVE We sought to evaluate the effect of antepartum and intrapartum antibiotic use on antimicrobial-resistant neonatal sepsis. STUDY DESIGN We analyzed perinatal outcomes for 8474 pregnancies (8593 live births) delivered at 6 hospitals. Data were collected regarding maternal antibiotic use and perinatal course, neonatal cultures, and outcomes. The diagnosis of confirmed neonatal sepsis required at least one positive blood or cerebrospinal fluid culture. Neonatal cultures were evaluated on the basis of the occurrence and timing of maternal antibiotic exposure. RESULTS There were 96 neonates with confirmed sepsis (11.2/1000 live births). Sepsis was 19.3-fold more common after preterm birth (57 vs 3. 1/1000; P <.001), with 76% of septic infants being delivered preterm. Forty-five percent of pathogens were ampicillin resistant. Ampicillin resistance increased with preterm birth (50% vs 26%; P =. 04), antepartum antibiotics (57% vs 34%; P =.03), intrapartum antibiotics (55% vs 28%; P <.01), and any prenatal antibiotic exposure (52% vs 22%; P =.01). Infection with an organism resistant to at least one maternal antibiotic was more common with intrapartum antibiotic exposure than with antepartum exposure only (57% vs 17%; P =.01). Regarding early-onset sepsis (n = 55), ampicillin resistance was more common with intrapartum antibiotics (50% vs 16%; P <.01), and resistance to at least one maternally administered antibiotic was more frequent with intrapartum exposure (56.7% vs 0%; P <.01). CONCLUSIONS Maternal antibiotic treatment is associated with neonatal sepsis by organisms resistant to ampicillin and to maternally administered antibiotics.

Relationship of prenatal care and perinatal morbidity in low-birth-weight infants

OBJECTIVE Lack of or no prenatal care (NPC) is associated with preterm birth (PTB) and low birth weight (LBW). Our purpose was to determine whether LBW infants delivered after NPC have worse outcomes than LBW infants with prenatal care (PC). STUDY DESIGN Eight thousand sixty-five consecutive women delivered at six hospitals in Shelby County, Tenn, were evaluated regarding clinical characteristics and perinatal outcomes depending on the occurrence of PC. Infant and LBW infant outcomes were evaluated on the basis of the occurrence of PC. Multivariate analysis was performed for neonatal outcomes adjusting for race, plurality, antenatal steroids, amnionitis, and ponderal index. A P value less than .05 was considered significant. RESULTS NPC women were more likely multiparous (80% vs 65%), African American (70% vs 61%), and uninsured (25% vs 4%), P<.0001 for each. PTB (36% vs 15%) and LBW (22% vs 12%) were more common with NPC, P<.0001 for each. Women with NPC had more advanced cervical dilation (ACD) greater than 4 cm (ACD: 63% vs 39%) and more amnionitis on admission (2% vs 1%), P<or=.001 for each, and had more fetal distress in labor, P=.02. NPC infants had increased mortality, respiratory distress syndrome, intraventricular hemorrhage, retinopathy, and bronchopulmonary dysplasia. Among LBW infants, NPC was associated with premature rupture of membranes, antepartum hemorrhage, amnionitis, and ACD. Controlling for other factors, NPC LBW infants had increased mortality (17% vs 9%), respiratory distress syndrome (31% vs 24%), intraventricular hemorrhage (10% vs 5%), retinopathy (13% vs 9%), and bronchopulmonary dysplasia (11% vs 7%), P<or=.04 for each. CONCLUSION In addition to increasing PTB and LBW, NPC is associated with increased perinatal morbidity and mortality among LBW infants after controlling for confounding factors.

A comparison of the bioavailability of oral and intramuscular dexamethasone in women in late pregnancy

Objective To compare the bioavilability of oral and intramuscular (IM) dexamthasonei in third-trimester pregnant women. Methods Oral and IM dexamethasone levels were compared in a randomized, parallel, crossover bioavailability study involving 11 gravid women in the third trimester of pregnancy. Subjects were randomized to receive either 6 mg of IM or 8 mg of oral dexamethasone. The following week, the alternative regimen was administered. Serial blood samples were obtained after drug administration. Dexamethasone concentrations were measured by radioimmunoassay. Total area under the curve was compared for the oral and IM groups using a paired t test. Results Eight of the 11 women completed the study through 12 hours; all 11 women completed the study through 6 hours. Among the 11 women, peak levels of dexamethasone occurred 30 minutes after IM injection (mean ± standardf deviation, 101.7 ± 19.2 ng/mL) and 120 minutes after oral administration (65.9 ± 20.5 ng/mL). Area under the curve did not differ significantly between those receiving IM dexamethasone (258.3 ± 50.0 ng/minu/mL) when measured 6 hours after administration of the drug. Terminal half-lives were similar in the IM and oral groups. Similar findings were noted among the eight women who were studied through 12 hours. This study had a power of 87% to detect a 20% difference in area under the curve between the two groups. Conclusion The bioavailability of 8 mg of oral dexamethasone is similar to that of a 6-mg IM dose, as determined by the area under the curve.