We examined the hypothesis that amniotic fluid (AF) infection and elevated cytokine concentrations may cause neonatal injury beyond that expected solely from prematurity.
Methods
The effects of exposure to AF infection and elevated cytokine concentrations were measured in 151 infants born to afebrile women in preterm labor with intact membranes at less than or equal to 34 weeks' gestation. Amniotic fluid was collected by amniocentesis for culture and determination of tumor necrosis factor-alpha and interleukin-6. Cytokine concentrations, stratified by AF infection, were compared for three gestational age groups. We then examined the associations between a positive AF culture or elevated AF tumor necrosis factor-alpha concentration and adverse neonatal outcomes, adjusted for birth weight.
Results
Amniotic fluid from 45 (30%) of 151 pregnancies had microorganisms, an elevated tumor necrosis factor-alpha concentration, or both. Amniotic fluid cytokine concentrations were significantly higher among women in preterm labor at less than or equal to 30 weeks, compared with 31-34 weeks. Nine of 11 infants who died at less than or equal to 24 hours of age had AF infection or elevated AF tumor necrosis factor-alpha. For the 140 surviving infants, AF infection and/or an elevated AF tumor necrosis factor-alpha was associated with respiratory distress syndrome (adjusted odds ratio [OR] 1.7), grade 3-4 intraventricular hemorrhage (adjusted OR 2.2), necrotizing enterocolitis (adjusted OR 1.8), and multiple organ dysfunction (adjusted OR 3.0).
Conclusion
Among infants born at less than or equal to 34 weeks to women who have intact membranes and are initially afebrile, those exposed to AF bacteria or cytokines have more adverse neonatal outcomes than unexposed infants of similar birth weight.
PMID 11755557 11755557 DOI 10.1016/s0029-7844(01)01567-8 10.1016/s0029-7844(01)01567-8 Hitti et al. 2002, Hitti 2002
Cite this article
Hitti, J., Tarczy-Hornoch, P., Murphy, J., Hillier, S. L., Aura, J., & Eschenbach, D. A. (2001). Amniotic fluid infection, cytokines, and adverse outcome among infants at 34 weeks' gestation or less. Obstetrics and gynecology, 98(6), 1080-1088. https://doi.org/10.1016/s0029-7844(01)01567-8
Hitti J, Tarczy-Hornoch P, Murphy J, Hillier SL, Aura J, Eschenbach DA. Amniotic fluid infection, cytokines, and adverse outcome among infants at 34 weeks' gestation or less. Obstet Gynecol. 2001;98(6):1080-1088. doi:10.1016/s0029-7844(01)01567-8
Hitti, J., et al. "Amniotic fluid infection, cytokines, and adverse outcome among infants at 34 weeks' gestation or less." Obstetrics and gynecology, vol. 98, no. 6, 2001, pp. 1080-1088.
To compare ampicillin with and without sulbactam with respect to the effect on the latency period after preterm premature rupture of membranes (PROM). Patients with PROM at 25-35 weeks' gestation were offered participation in a randomized blinded trial comparing ampicillin-sulbactam with ampicillin. Evaluations for cervical pathogens were performed on admission and patients were followed-up with daily maternal and fetal evaluation. Maternal and neonatal outcomes were analyzed using indicated techniques. Fifty-three women were studied, with 25 receiving ampicillin-sulbactam and 28 receiving ampicillin. The ampicillin-sulbactam group had a significantly longer latency period (433 +/- 625 versus 143 +/- 165 hours, P = .03) and significantly fewer neonatal complications (five versus 20, P < .001). Although no neonatal infectious complications were observed in sulbactam-treated cases, there were four cases of neonatal sepsis and two of neonatal pneumonia in the ampicillin group. Also, significantly more neonates in the ampicillin group required prolonged oxygen and ventilatory support. There was no significant difference in maternal morbidity. In our population with preterm PROM, a broad-spectrum antibiotic that provides anaerobic coverage appears to extend latency and decrease neonatal morbidity without increasing adverse maternal outcome.
The relationship between asymptomatic bacteriuria and prematurity/low birth weight (LBW) is still a controversial issue, despite many studies. Meta-analysis, a research tool designed to analyze and combine the results of previous studies, may resolve this discrepancy among contradictory results of clinical trials. The purpose of this study was to examine the relationship between asymptomatic bacteriuria and preterm delivery/LBW using meta-analysis. Reports from the literature were classified according to study design into cohort or randomized-treatment control trials. Meta-analysis of cohort studies showed that untreated asymptomatic bacteriuria during pregnancy significantly increased rates of LBW and preterm delivery. Nonbacteriuric patients had only about two-thirds the risk (typical relative risk = 0.65; 95% confidence interval 0.57, 0.74) of LBW and half the risk (typical relative risk = 0.50; 95% confidence interval 0.36, 0.70) of preterm delivery of those with untreated asymptomatic bacteriuria. These reduced risks correspond to a 3.4 (confidence interval 1.8, 5.0) percentage-point difference in LBW and a 3.8 (1.1, 6.4) percentage-point difference in preterm delivery. The analysis of randomized clinical trials showed that antibiotic treatment significantly reduced the risk of LBW (typical relative risk = 0.56; 95% confidence interval 0.43, 0.73), with a substantial reduction of 6.4 (confidence interval 3.3, 9.5) percentage points in the rate of LBW. We conclude that clinical and epidemiologic evidence indicates a strong association between untreated asymptomatic bacteriuria and LBW/preterm delivery and that antibiotic treatment is effective in reducing the occurrence of LBW.
Lee YL et al., 2022·Scientific Reports·
Open Access
Preterm delivery of low-birth weight infants is considered a leading cause of morbidity and mortality among neonates. Various studies have reported a positive correlation between periodontal disease (PD) and premature birth (PB) and yet no population-based study has assessed the impact of PD severity and treatments on premature birth. This cohort study used Taiwan's national medical records (1999-2012, included 1,757,774 pregnant women) to investigate the association between PD severity and PB. Women with PD during the 2-year period prior for giving birth were more likely to have PB (11.38%) than those without PD (10.56%; p < 0.001). After variables adjustment, the advanced PD group had OR of 1.09 (95% CI 1.07-1.11) for PB, the mild PD group had OR of 1.05 (95% CI 1.04-1.06), while no-PD group had OR of 1. Increased PD severity was related to higher risk of PB. When stratified by age, the highest ORs for PB were those aged from 31 to 35 years in both mild PD group (OR = 1.09, 95% CI 1.07-1.11) and advanced PD group (OR = 1.13, 95% CI 1.09-1.17). Improving periodontal health before or during pregnancy may prevent or reduce the occurrence of adverse pregnancy outcomes and therefore maternal and perinatal morbidity and mortality.
Premature birth causes high rates of neonatal morbidity and mortality. There are multiple causes of preterm birth. This article reviews the evidence linking subclinical infection and premature birth. Although maternal genital tract colonization with specific organisms has been inconsistently associated with preterm birth and/or premature rupture of membranes, some infections have been consistently associated with preterm delivery. The association of histologic chorioamnionitis with prematurity is a consistent finding, but the mechanisms require further study. The relationship between histologic chorioamnionitis infection and the chorioamnionitis of prematurity requires additional research. A varying number of patients in "idiopathic" preterm labor have positive amniotic fluid cultures (0% to 30%), but it is not clear whether infection preceded labor or occurred as a result of labor. Evidence of subclinical infection as a cause of preterm labor is raised by finding elevated maternal serum C-reactive protein and abnormal amniotic fluid organic acid levels in some patients in preterm labor. Biochemical mechanisms for preterm labor in the setting of infection are suggested by both in vitro and in vivo studies of prostaglandins and their metabolites, endotoxin and cytokines. Some, but by no means all, antibiotic trials conducted to date have reported decreases in prematurity. These results support the hypothesis that premature birth results in part from infection caused by genital tract bacteria. In the next few years, research efforts must be prioritized to determine the role of infection and the appropriate prevention of this cause of prematurity.