New antibiotic regimen for preterm premature rupture of membrane reduces the incidence of bronchopulmonary dysplasia

Disturbance of fetal growth by azithromycin through induction of ER stress in the placenta

AIM

Azithromycin (AZM) is widely used to treat mycoplasma infection in pregnancy. However, there is no adequate evaluation of its side effect on the placenta. Here, by using human placental syncytiotrophoblasts and a mouse model, we investigated whether AZM use in pregnancy might adversely affect placental function and pregnancy outcome.

RESULTS

Transcriptomic analysis of AZM-treated human placental syncytiotrophoblasts showed increased expression of ER stress-related genes and decreased expression of genes for hormone production and growth factor processing. Verification studies showed that AZM increased the abundance of ER stress mediators (phosphorylated eIF2α, ATF4 and CHOP), and decreased the abundance of enzymes involved in progesterone and estradiol synthesis (STS, CYP11A1 and CYP19A1) and IGFBP cleavage (PAPPA and ADAM12) in human placental syncytiotrophoblasts. Inhibition of ER stress blocked AZM-induced decreases in the expression of CYP19A1, CYP11A1, PAPPA and ADAM12, suggesting that the inhibition of AZM on those genes' expression was secondary to AZM-induced ER stress. Further mechanism study showed that increased ATF4 in ER stress might repressively interact with C/EBPα to suppresstheexpression ofthose genes including CEBPAitself. Mouse studies showed that AZM administration decreased fetal weights along with increased ER stress mediators and decreased levels of insulin-like growth factor, estrogen and progesterone in the maternal blood, which could be alleviated by inhibition of ER stress.

INNOVATION AND CONCLUSION

These findings firstly support AZM, often used during pregnancy, may affect fetal growth by inhibiting crucial enzymes for estrogen and progesterone synthesis and disrupting crucial proteases for IGFBP cleavage via inducing ER stress in placental syncytiotrophoblasts.

Developing a Core Outcome Set for the Evaluation of Antibiotic Use in Prelabor Rupture of Membranes: A Systematic Review and Semi-Structured Interview

Background: Prelabor rupture of membranes (PROM) is associated with maternal and neonatal infections. Although guidelines suggest prophylactic antibiotics for pregnant women with PROM, the optimal antibiotic regimen remains controversial. Synthesizing the data from different studies is challenging due to variations in reported outcomes.

Objective: This study aimed to form the initial list of outcomes for the core outcome set (COS) that evaluates antibiotic use in PROM by identifying all existing outcomes and patients’ views.

Methods: Relevant studies were identified by searching PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang, and VIP databases. We also screened the references of the included studies as a supplementary search. We extracted basic information from the articles and the outcomes. Two reviewers independently selected the studies, extracted the data, extracted the outcomes, and grouped them into domains. Then, semi-structured interviews based on the potential factors collected by the systematic review were conducted at West China Second Hospital of Sichuan University. Pregnant women who met the diagnostic criteria for PROM were enrolled. Participants reported their concerns about the outcomes. Two researchers identified the pregnant women’s concerns.

Results: A total of 90 studies were enrolled in this systematic review. The median outcomes in the included studies was 7 (1–31), and 109 different unique outcomes were identified. Pre-term PROM (PPROM) had 97 outcomes, and term PROM (TPROM) had 70 outcomes. The classification and order of the core outcome domains of PPROM and TPROM were consistent. The physiological domain was the most common for PPROM and TPROM outcomes. Furthermore, 35.1 and 57.1% outcomes were only reported once in PPROM and TPROM studies, respectively. Thirty pregnant women participated in the semi-structured interviews; 10 outcomes were extracted after normalized, and the outcomes were reported in the systematic review. However, studies rarely reported pregnant women’s concerns.

Conclusion: There was considerable inconsistency in outcomes selection and reporting in studies about antibiotics in PROM. An initial core outcomes set for antibiotics in PROM was formed.

Genital Mycoplasmas and Biomarkers of Inflammation and Their Association With Spontaneous Preterm Birth and Preterm Prelabor Rupture of Membranes: A Systematic Review and Meta-Analysis

Genital mycoplasmas (GM), such as Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma parvum, and Ureaplasma urealyticum are commonly associated with spontaneous preterm labor (SPTL), spontaneous preterm birth (PTB), and preterm prelabor rupture of membranes (PPROM). This study determined the association between GM and such adverse pregnancy outcomes. We searched for studies published 1980–2019 in MEDLINE, EMBASE, and Web of Science. Studies were eligible when GM was detected during pregnancy. We included 93 and 51 studies in determining the prevalence and the inflammatory biomarkers associated with GM, respectively, using the “metafor” package within R. The protocol was registered with PROSPERO (registration no. CRD42016047297). Women with the studied adverse pregnancy outcomes had significantly higher odds of presence with GM compared to women who delivered at term. For PTB, the odds ratios were: M. hominis (OR: 2.25; CI: 1.35–3.75; I²: 44%), M. genitalium (OR: 2.04; CIL 1.18–3.53; I²: 20%), U. parvum (OR: 1.75; CI: 1.47–2.07; I²: 0%), U. urealyticum (OR: 1.50; CI: 1.08–2.07; I²: 58%). SPTL had significantly higher odds with M. hominis (OR: 1.96; CI: 1.19–3.23; I²: 1%) or U. urealyticum (OR: 2.37; CI: 1.20–4.70; I²: 76%) compared to women without SPTL. Women with PPROM had significantly higher odds with M. hominis (OR: 2.09; CI: 1.42–3.08; I²: 0%) than women without PPROM. However, our subgroup analysis based on the diagnostic test and the sample used for detecting GM showed a higher prevalence of GM in maternal samples than in fetal samples. GM presence of the cervix and vagina was associated with lower odds of PTB and preterm labor (PTL). In contrast, GM presence in the AF, fetal membrane, and placenta was associated with increased odds of PTB and PTL. However, genital mycoplasmas may not elicit the massive inflammation required to trigger PTB. In conclusion, GM presence in the fetal tissues was associated with significantly increased odds of PTB and PTL.

Antenatal Antibiotic Exposure Affects Enteral Feeding, Body Growth, and Neonatal Infection in Preterm Infants: A Retrospective Study

Background: Antibiotics are widely prescribed by obstetricians, which exposes a large number of infants to antenatal antibiotics (AAB). The effect of AAB on various aspects of neonatal development of preterm infants remains unclear. Methods: In this retrospective study, infants born with gestational age (GA) between 22 ⁺⁰ and 36 ⁺⁶ weeks at our unit from 2017 to 2019 were included. Multivariable analysis was adopted to examine the associations between AAB exposure and various outcomes related to enteral feeding process, body growth, and neonatal infection after adjusting for potential confounders. Further subanalysis on the exposure level of AAB and stratified analysis by GA (<34 vs. ≥34 weeks) were also conducted. Results: In this cohort comprising 2,543 preterm infants, AAB was associated with decreased risks of feeding intolerance (odds ratio [OR]: 0.63, 95% confidence interval [CI]: 0.48-0.82) and neonatal infection (OR: 0.63, 95% CI: 0.41-0.94). Higher AAB exposure level was associated with higher Z scores of birth weight (β = 0.37, 95% CI: 0.27-0.47), but lower Δbodyweight Z-scores (β = -0.20, 95% CI: -0.27 to -0.13). AAB was positively associated with the parameters related to body growth in infants with GA <34 weeks but negatively associated in those with GA ≥34 weeks. Conclusions: AAB exposure affects the enteral feeding process and neonatal infection. The effects on body growth vary by the exposure level of AAB and GA of infants. A well-designed prospective and preferably multi-centre study with predefined parameters is required to confirm our findings.

Erythromycin compared to amoxicillin and azithromycin for antimicrobial prophylaxis for preterm premature rupture of the membranes: a retrospective study

Antimicrobial prophylaxis is widely recommended for pregnant women who have preterm premature rupture of the membranes. Erythromycin prophylaxis was used during an initial period (control) and then changed to intravenous amoxicillin for 48 h, followed by 5 days of oral amoxicillin along with a single dose of azithromycin (case). Healthcare records were reviewed retrospectively. The primary outcome was latency (between membrane rupture and delivery) and the secondary outcomes were mode of delivery, maternal high dependency unit (HDU) admission, and several laboratory parameters. There were 78 women in the case group (amoxicillin and azithromycin) and controls were selected on a 1:1 ratio. There was no statistically significant difference between cases and controls with respect to group B Streptococcus or E.coli carriage, previous preterm birth, assissted fertility and parity. No babies had a positive blood culture with Group B Streptococcus. There was a longer latency to delivery for those prescribed amoxicillin and azithromycin (median = 5.5 days), compared with controls on erythromycin (median = 2 days, p < .001). There was no difference in the mode of delivery or maternal HDU admission. Given the potential sequelae of preterm birth, this warrants further prospective investigation in a randomised control trial.IMPACT STATEMENTWhat is already known on this subject? Antimicrobial prophylaxis is recommended for women who have preterm premature rupture of the membranes (PPROM). It has been shown to increase latency of delivery. However there are different regimens recommended in North America (amoxicillin and a macrolide) and the United Kingdom (macrolide monotherapy).What do the results of this study add? This study has shown that in our population, women who were prescribed the PPROM regimen of amoxicillin with azithromycin had a longer median latency from time of rupture of membranes to delivery, than women in a historical control group who were prescribed erythromycin monotherapy.What are the implications of these findings for clinical practice and/or further research? This retrospective study has shown that there may be a difference in latency between different antimicrobial prophylaxis regimens for PPROM. A randomised control trial, with sufficient patient numbers, is needed to determine the best regimen for prophylaxis, and would allow harmonisation of international guidelines.

Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes

BACKGROUND

Preterm prelabor rupture of the membranes (PPROM) is frequently complicated by intraamniotic inflammatory processes such as intraamniotic infection and sterile intraamniotic inflammation. Antibiotic therapy is recommended to patients with PPROM to prolong the interval between this complication and delivery (latency period), reduce the risk of clinical chorioamnionitis, and improve neonatal outcome. However, there is a lack of information regarding whether the administration of antibiotics can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with PPROM.

OBJECTIVE

The first aim of the study was to determine whether antimicrobial agents can reduce the magnitude of the intraamniotic inflammatory response in patients with PPROM by assessing the concentrations of interleukin-6 in amniotic fluid before and after antibiotic treatment. The second aim was to determine whether treatment with intravenous clarithromycin changes the microbial load of Ureaplasma spp DNA in amniotic fluid.

STUDY DESIGN

A retrospective cohort study included patients who had (1) a singleton gestation, (2) PPROM between 24+0 and 33+6 weeks, (3) a transabdominal amniocentesis at the time of admission, and (4) intravenous antibiotic treatment (clarithromycin for patients with intraamniotic inflammation and benzylpenicillin/clindamycin in the cases of allergy in patients without intraamniotic inflammation) for 7 days. Follow-up amniocenteses (7^th day after admission) were performed in the subset of patients with a latency period lasting longer than 7 days. Concentrations of interleukin-6 were measured in the samples of amniotic fluid with a bedside test, and the presence of microbial invasion of the amniotic cavity was assessed with culture and molecular microbiological methods. Intraamniotic inflammation was defined as a bedside interleukin-6 concentration ≥745 pg/mL in the samples of amniotic fluid. Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity.

RESULTS

A total of 270 patients with PPROM were included in this study: 207 patients delivered within 7 days and 63 patients delivered after 7 days of admission. Of the 63 patients who delivered after 7 days following the initial amniocentesis, 40 underwent a follow-up amniocentesis. Patients with intraamniotic infection (n = 7) and sterile intraamniotic inflammation (n = 7) were treated with intravenous clarithromycin. Patients without either microbial invasion of the amniotic cavity or intraamniotic inflammation (n = 26) were treated with benzylpenicillin or clindamycin. Treatment with clarithromycin decreased the interleukin-6 concentration in amniotic fluid at the follow-up amniocentesis compared to the initial amniocentesis in patients with intraamniotic infection (follow-up: median, 295 pg/mL, interquartile range [IQR], 72-673 vs initial: median, 2973 pg/mL, IQR, 1750-6296; P = .02) and in those with sterile intraamniotic inflammation (follow-up: median, 221 pg/mL, IQR 118-366 pg/mL vs initial: median, 1446 pg/mL, IQR, 1300-2941; P = .02). Samples of amniotic fluid with Ureaplasma spp DNA had a lower microbial load at the time of follow-up amniocentesis compared to the initial amniocentesis (follow-up: median, 1.8 × 10⁴ copies DNA/mL, 2.9 × 10⁴ to 6.7 × 10⁸ vs initial: median, 4.7 × 10⁷ copies DNA/mL, interquartile range, 2.9 × 10³ to 3.6 × 10⁷; P = .03).

CONCLUSION

Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation. Moreover, treatment with clarithromycin was related to a reduction in the load of Ureaplasma spp DNA in the amniotic fluid of patients with PPROM <34 weeks of gestation.

Nutrients and Microbiota in Lung Diseases of Prematurity: The Placenta-Gut-Lung Triangle

Cardiorespiratory function is not only the foremost determinant of life after premature birth, but also a major factor of long-term outcomes. However, the path from placental disconnection to nutritional autonomy is enduring and challenging for the preterm infant and, at each step, will have profound influences on respiratory physiology and disease. Fluid and energy intake, specific nutrients such as amino-acids, lipids and vitamins, and their ways of administration -parenteral or enteral-have direct implications on lung tissue composition and cellular functions, thus affect lung development and homeostasis and contributing to acute and chronic respiratory disorders. In addition, metabolomic signatures have recently emerged as biomarkers of bronchopulmonary dysplasia and other neonatal diseases, suggesting a profound implication of specific metabolites such as amino-acids, acylcarnitine and fatty acids in lung injury and repair, inflammation and immune modulation. Recent advances have highlighted the profound influence of the microbiome on many short- and long-term outcomes in the preterm infant. Lung and intestinal microbiomes are deeply intricated, and nutrition plays a prominent role in their establishment and regulation. There is an emerging evidence that human milk prevents bronchopulmonary dysplasia in premature infants, potentially through microbiome composition and/or inflammation modulation. Restoring antibiotic therapy-mediated microbiome disruption is another potentially beneficial action of human milk, which can be in part emulated by pre- and probiotics and supplements. This review will explore the many facets of the gut-lung axis and its pathophysiology in acute and chronic respiratory disorders of the prematurely born infant, and explore established and innovative nutritional approaches for prevention and treatment.

Continuous amnioinfusion for treatment of mid-trimester preterm premature rupture of membranes with oligoamnios

AIM

Given the scarcity of relevant reports, this study aimed to elucidate whether pregnancy can be prolonged by maintaining the amniotic fluid volume with continuous transabdominal amnioinfusion (TA) for patients with mid-trimester preterm premature rupture of membranes (PPROM) and oligoamnios.

METHODS

We retrospectively examined patients who were managed during hospitalization at our department after developing PPROM between week 22 day 0 and week 25 day 6 of gestation and subsequent oligoamnios (amniotic fluid index [AFI] <5 cm) within 7 days after PPROM onset. Cases between 2006 and 2011 comprised the conventional management group (n = 14); cases administered continuous TA between 2012 and 2017 comprised the continuous TA group (n = 14). The primary outcome was the number of days between PPROM and delivery. The secondary outcomes were the proportion of normal amniotic fluid volume (AFI ≥ 5 cm) maintained between PPROM and delivery and the perinatal prognosis for the mother and infant.

RESULTS

The continuous TA group had significantly more days between PPROM and delivery and a significantly higher proportion of days that a normal amniotic fluid volume was maintained during that period, regardless of antimicrobial agents administered. Although no significant differences in the perinatal prognosis of disease were found between groups, there was a decreasing trend of composite perinatal mortality and morbidity, and the incidence rates were reduced by half.

CONCLUSION

Continuous TA for PPROM with oligoamnios may allow significant prolongation of the gestation period while maintaining the amniotic fluid volume and may lead to improved perinatal prognosis.

Current understanding and treatment of intra-amniotic infection with Ureaplasma spp

Considerable evidence has shown that intra-amniotic infection with Ureaplasma spp. increases the risk of chorioamnionitis and preterm labor. Ureaplasma spp. are among the smallest organisms, and their isolation is uncommon in routine clinical practice because of their size and high auxotrophy. Although Ureaplasma spp. have been reported as causative agents of preterm birth, they also have a high incidence in vaginal swabs collected from healthy reproductive-age women; this has led to questions on the virulence of Ureaplasma spp. and to them being considered as harmless commensal bacteria. Therefore, many efforts have been made to clarify the pathogenicity of Ureaplasma spp. at the molecular level. Ureaplasma spp. are surrounded by lipoproteins, including multiple-banded antigen. Both multiple-banded antigen and its derivative, that is, the synthetic lipopeptide, UPM-1, induce an inflammatory response in a preterm mice model, which was adequate to cause preterm birth or stillbirth. In this review, we present an overview of the virulence mechanisms of Ureaplasma spp. and treatment of ureaplasma infection during pregnancy to prevent possible serious sequelae in infants. In addition, relevant mechanisms underlying antibiotic resistance in Ureaplasma spp. are discussed. Ureaplasma spp. are naturally resistant against β-lactam antibiotics because of the lack of a cell wall. Azithromycin is one of the effective agents that can control intrauterine ureaplasma infection. In fact, macrolide- and fluoroquinolone-resistant isolates of Ureaplasma spp. have already been observed in perinatal practice in Japan.