Preterm Birth Infection Research Articles

Periodontal diseases in pregnant women as a risk factor: a concise systematic review

This study highlighted that periodontal diseases in pregnant women can be one of the determinants of low birth weight. Studies were carried out to verify the existence of an association between maternal periodontal disease and low birth weight. Gestational period, where the occurrence of periodontal diseases (PD) is more likely, due to its hormonal and physiological changes. Therefore, pregnant women must be alert and take proper care, have prenatal care with their dentist, in addition to their oral care, they must be alert to the risks of low birth weight and premature births. Infections in regions of the genitourinary tract, such as PD, may be associated with the occurrence of low birth weight newborns through the same mechanisms as other maternal and preterm birth infections. The contraction of the uterus and cervical dilation, acting as a trigger for premature birth, can be caused by inflammatory stimuli, which can induce hyperirritability of the uterine smooth muscles. The infection and the resulting inflammatory process can cause damage to the placenta, thereby restricting fetal development. Throughout life, a woman goes through several phases of hormonal fluctuations that, in addition to interfering with the reproductive system, exert influence on other organs and systems, such as the periodontium, particularly in the presence of preexisting gingival inflammation induced by plaque. During pregnancy, a woman is exposed to several significant hormonal changes, as the placenta produces high amounts of estrogen and progesterone, which in turn affect the oral tissues. It was concluded that black women aged over 40 years old are more likely to have PD, having a higher risk of low development to the fetus.

Relationship between histologic chorioamnionitis and genital tract cultures in pre term labour

The objective was to determine the relationship of histological chorioamnionitis (HCA) with genital tract cultures in preterm birth. Among two hundred women recruited for the study, 100 were taken as cases with gestational age between ≥28 and <37 weeks and 100 women with gestational age >37 weeks were taken as controls. Vaginal swabs were taken for culture sensitivity and vaginal smears were made for performing whiff test and heat dry gram stained smear was examined for growth of microorganisms. Histopathologic examination of the placenta was done after delivery. 49 cases and 26 controls had evidence of histological chorioamnionitis. A significant difference was observed in relation to the presence of E. coli, presence of clue cells, positive whiff test and occurrence of bacterial vaginosis in subjects with and without histological chorioamnionitis. Thus, we conclude that the presence of histological chorioamnionitis is closely related to the presence of pathogenic microorganisms in the cervicovaginal region. IMPACT STATEMENT What is already known on the subject? Histologic chorioamnionitis has been regarded to reflect amniotic fluid infection and there are studies showing an association between histologic chorioamnionitis, amniotic fluid, and subchorionic plate cultures. Nevertheless, studies of the correlation of the cervical swab cultures with intrauterine infection in preterm birth remain inconclusive. What do the results of this study add? Histologic chorioamnionitis is closely related to the presence of pathogenic microorganisms in the cervicovaginal region. What are the implications of these findings for clinical practice and/or further research? High vaginal swab cultures and gram staining of vaginal smear is useful in detecting antenatal patients who are at a higher risk for preterm labour. After detection, early intervention may be done to avoid preterm deliveries in these high-risk pregnancies.

The role of maternal infection in preterm birth: evidence from the Brazilian Multicentre Study on Preterm Birth (EMIP)

OBJECTIVES:Evidence suggests that infection or inflammation is a major contributor to early spontaneous preterm birth (sPTB). Therefore, this study aimed to investigate the development and causes of maternal infection associated with maternal and neonatal outcomes in women with sPTB.METHODS:This was a secondary analysis of a multicenter cross-sectional study with a nested case–control component, the Brazilian Multicentre Study on Preterm Birth (EMIP), conducted from April 2011 to July 2012 in 20 Brazilian referral obstetric hospitals. Women with preterm birth (PTB) and their neonates were enrolled. In this analysis, 2,682 women undergoing spontaneous preterm labor and premature pre-labor rupture of membranes were included. Two groups were identified based on self-reports or prenatal or hospital records: women with at least one infection factor and women without any maternal infection (vulvovaginitis, urinary tract infection, or dental infection). A bivariate analysis was performed to identify potential individual risk factors for PTB. The odds ratios (ORs) with their respective 95% confidence intervals were calculated.RESULTS:The majority of women with sPTB fulfilled at least one criterion for the identification of maternal infection (65.9%), and more than half reported having urinary tract infection during pregnancy. Approximately 9.6% of women with PTB and maternal infection were classified as having periodontal infection only. Apart from the presence of a partner, which was more common among women with infectious diseases (p=0.026; OR, 1.28 [1.03-1.59]), other variables did not show any significant difference between groups.CONCLUSION:Maternal infection was highly prevalent in all cases of sPTBs, although it was not clearly associated with the type of PTB, gestational age, or any adverse neonatal outcomes.

Pregnancy and Neonatal Outcomes of Group B Streptococcus Infection in Preterm Births

Objective: This study examines whether maternal group B Streptococcus (Streptococcus agalactiae, GBS) infection was associated with preterm births and premature neonatal outcomes. Methods: Maternal and neonatal outcomes were examined among singleton pregnant women with preterm birth (from 24+0 weeks to 36+6 weeks) who were tested for GBS (n=203) during the pregnancy. Data were collected retrospectively from the medical records of women who delivered at our hospital from January 2015 to February 2017. We compared obstetrical factors (causes of preterm birth) and neonatal (gestational age at delivery, birth weight, Apgar score 1 min/5 min, hospitalization period, duration of mechanical ventilation, neonatal C-reactive protein within three days, and other complication [respiratory distress syndrome, neonatal deaths]) outcomes between GBS-infected and non-infected pregnant women. Results: There were 203 singleton pregnant women included in the study, 25 of whom were confirmed to have a GBS infection during the pregnancy. There was no difference in neonatal outcomes by GBS status. Preterm premature rupture of membranes (pPROM), as an obstetric factor, was associated with GBS infection (P=0.022). GBS infection raised the risk of pPROM by 3.6 times (odds ratio 3.648, 95% confidence interval 1.476-9.016, P=0.005). Conclusion: GBS infection in preterm birth was associated with pPROM but did not result in adverse neonatal outcomes. Continuous attention and evaluation of GBS infection, a major cause of neonatal sepsis and pneumonia, are needed.

The relationship of circulating proteins in early pregnancy with preterm birth

Preterm birth (PTB) (< 37 completed weeks' gestation) is a pathological outcome of pregnancy and a major global health problem. Babies born preterm have an elevated risk for long-term adverse medical and neurodevelopmental sequelae. Substantial evidence implicates intrauterine infection and/or inflammation in PTB. However, these are often relatively late findings in the process, when PTB is inevitable. Identification of earlier markers of PTB may make successful intervention possible. Although select proteins, notably those related to theinflammatory pathways, have been associated with PTB, there has been a lack of research into the role of other protein pathways in the development of PTB. The purpose of this study was to investigate, using a previously described biomarker discovery approach, a subset of circulating proteins and their association with PTB focusing on samples from early pregnancy. The objectives of the study were as follows: (1) to perform a large-scale biomarker discovery, utilizing an innovative platform to identify proteins associated with preterm birth in plasma taken between 10 and 15 weeks' gestation and, (2) to determine which protein pathways are most strongly associated with preterm birth. To address these aims, we measured 1129 proteins in a plasma sample from early pregnancy using a multiplexed aptamer-based proteomic technology developed in Colorado by SomaLogic. Using a nested case-control approach, we measured proteins at a single time point in early pregnancy in 41 women who subsequently delivered preterm and 88 women who had term uncomplicated deliveries. We measured 1129 proteins using a multiplexed aptamer-based proteomic technology developed by SomaLogic. Logistic regressions and random forests were used to compare protein levels. The complement factors B and H and the coagulation factors IX and IX ab were the highest-ranking proteins distinguishing cases of preterm birth from term controls. The top 3 pathways associated with preterm birth were the complement cascade, the immune system, and the clotting cascade. Using a discovery approach, these data provide further confirmation that there is an association of immune- and coagulation-related events in early pregnancy with preterm birth. Thus, plasma protein profiles at 10-15 weeks of gestation are related to the development of preterm birth later in pregnancy.

Inflammation, Infection and Preterm Birth

Preterm birth is the leading cause of perinatal morbidity and mortality. Pathological processes that have been linked with preterm birth infection and / or intrauterine inflammation are most frequently found associated with their induction. Studies in animal models and human research showed prior infections to the induction of labor, the anteriority of infection over labor induction, and the existence of a subclinical latency phase between these two phenomena. The ascending route from the vagina and the cervix is preponderant but also microorganisms may access the amniotic cavity and the fetus by other pathways. During inflammation associated to infection, Prostaglandins are released simultaneously with Nitric oxide and their overproduction could be detrimental. Prostaglandins promote uterine contractions contributing to embryonic and fetal expulsion. Therefore aberrant activation of the inflammatory response may cause premature labor and this does not seem to depend on how the microoorganisms accessed the uterus.

The role of inflammation and infection in preterm birth.

Inflammation has been implicated in the mechanisms responsible for preterm and term parturition, as well as fetal injury. Out of all of the suspected causes of preterm labor and delivery, infection and/or inflammation is the only pathological process for which both a firm causal link with preterm birth has been established and a molecular pathophysiology defined. Inflammation has also been implicated in the mechanism of spontaneous parturition at term. Most cases of histopathological inflammation and histological chorioamnionitis, both in preterm and term labor, are sub-clinical in nature. The isolation of bacteria in the amniotic fluid, known as microbial invasion of the amniotic cavity, is a pathological finding; the frequency of which is dependent upon the clinical presentation and gestational age. This article reviews the role of inflammation in preterm and term parturition.

Antibiotics for asymptomatic bacteriuria in pregnancy.

Up to 30% of mothers develop acute pyelonephritis if asymptomatic bacteriuria is untreated. Asymptomatic bacteriuria may have a role in preterm birth, or it may be a marker for low socioeconomic status and thus, low birth weight. The objective of this review was to assess the effect of antibiotic treatment for asymptomatic bacteriuria on persistent bacteriuria during pregnancy, the risk of preterm delivery and the development of pyelonephritis after delivery. I searched the Cochrane Pregnancy and Childbirth Group trials register. Randomised trials comparing antibiotic treatment with placebo or no treatment in pregnant women with asymptomatic bacteriuria found on antenatal screening. Trial quality was assessed. Thirteen studies were included. Overall the study quality was not strong. Antibiotic treatment compared to placebo or no treatment was effective in clearing asymptomatic bacteriuria (odds ratio 0.07, 95% confidence interval 0.05 to 0.10). The incidence of pyelonephritis was reduced (odds ratio 0.25, 95% confidence interval 0.19 to 0.32). Antibiotic treatment was also associated with a reduction in the incidence of preterm delivery or low birth weight babies (odds ratio 0.60, 95% confidence interval 0.45 to 0.80). Antibiotic treatment appears to be effective in reducing the risk of pyelonephritis in pregnancy. An apparent reduction in preterm delivery is consistent with current theories about the role of infection in preterm birth, but this association should be interpreted with caution.