Lactobacilli-dominated cervical microbiota in women with preterm prelabor rupture of membranes

Uterine Microbiota and Bisphenols: Novel Influencers in Reproductive Health

Infertility affects 8-12% of couples worldwide, and 30-75% of preclinical pregnancy losses are due to a failure during the implantation process. Exposure to endocrine disruptors, like bisphenols, among others, has been associated with the increase in infertility observed in the past decades. An increase in infertility has correlated with exposure to endocrine disruptors like bisphenols. The uterus harbors its own microbiota, and changes in this microbiota have been linked to several gynecological conditions, including reproductive failure. There are no studies on the effects of bisphenols on the uterine-microbiota composition, but some inferences can be gleaned by looking at the gut. Bisphenols can alter the gut microbiota, and the molecular mechanism by which gut microbiota regulates intestinal permeability involves Toll-like receptors (TLRs) and tight junction (TJ) proteins. TJs participate in embryo implantation in the uterus, but bisphenol exposure disrupts the expression and localization of TJ proteins. The aim of this review is to summarize the current knowledge on the microbiota of the female reproductive tract (FRT), its association with different reproductive diseases-particularly reproductive failure-the effects of bisphenols on microbiota composition and reproductive health, and the molecular mechanisms regulating uterine-microbiota interactions crucial for embryo implantation. This review also highlights existing knowledge gaps and outlines research needs for future risk assessments regarding the effects of bisphenols on reproduction.

The Role of the Vaginal and Endometrial Microbiomes in Infertility and Their Impact on Pregnancy Outcomes in Light of Recent Literature

The Human Microbiome Project (HMP), initiated in 2007, aimed to gather comprehensive knowledge to create a genetic and metabolic map of human-associated microorganisms and their contribution to physiological states and predisposition to certain diseases. Research has revealed that the human microbiome is highly diverse and exhibits significant interpersonal variability; consequently, its exact impact on health remains unclear. With the development of next-generation sequencing (NGS) technologies, the broad spectrum of microbial communities has been better characterized. The lower female genital tract, particularly the vagina, is colonized by various bacterial species, with Lactobacillus spp. predominating. The upper female genital tract, especially the uterus, was long considered sterile. However, recent studies have identified a distinct endometrial microbiome. A Lactobacillus-dominated microbiome of the female genital tract is associated with favorable reproductive outcomes, including higher success rates in natural conception and assisted reproductive technologies (ART). Conversely, microbial imbalances, or dysbiosis, marked by reduced Lactobacilli as well as an increased diversity and abundance of pathogenic species (e.g., Gardnerella vaginalis or Prevotella spp.), are linked to infertility, implantation failure, and pregnancy complications such as miscarriage and preterm birth. Dysbiosis can impair the vaginal or endometrial mucosal barrier and also trigger pro-inflammatory responses, disrupting essential reproductive processes like implantation. Despite growing evidence supporting the associations between the microbiome of the female genital tract and certain gynecological and obstetric conditions, clear microbial biomarkers have yet to be identified, and there is no consensus on the precise composition of a normal or healthy microbiome. The lack of standardized protocols and biomarkers limits the routine use of microbiome screening tests. Therefore, larger patient cohorts are needed to facilitate comparative studies and improve our understanding of the physiological microbiome profiles of the uterus and vagina, as well as how dysbiosis may influence clinical outcomes. Further research is required to refine diagnostic tools and develop personalized therapeutic strategies to improve fertility and pregnancy outcomes.

History of cervical excisional treatment is associated with changes in the cervical microbiota in women with preterm prelabor rupture of membranes

BACKGROUND

This study aimed to determine the differences in the cervical load and prevalence of Lactobacillus crispatus DNA, Lactobacillus iners DNA, Gardnerella vaginalis DNA, Sneathia sanguinegens DNA, and Ureaplasma species DNA between pregnant women with preterm prelabor rupture of membranes (PPROM) with and without a history of cervical excisional treatment. We also assessed the changes in the cervical load and prevalence of L. crispatus DNA, L. iners DNA, G. vaginalis DNA, S. sanguinegens DNA, and U. spp DNA. according to the cone length.

METHODS

This retrospective study included 132 women with singleton pregnancies complicated by PPROM. For all women, information about the cervical loads of bacterial DNA corresponding to L. crispatus, L. iners, G. vaginalis, S. sanguinegens, and U. spp., which was assessed using PCR, was available.

RESULTS

Women with a history of cervical excisional treatment had a higher cervical load of L. iners DNA (4.4 × 106 copies DNA/mL vs. 3.5 × 105 copies DNA/mL, p = .04) and a higher load and prevalence of U. spp. DNA (1.1 × 105 copies DNA/mL vs. 9.6 × 104 copies DNA/mL, p = .03; 2.7% vs. 0.5%, p = .04) than those without a history of cervical excisional treatment. In the subset of women with a history of cervical excisional treatment, those with a cone length 18 mm and more had a lower relative abundance of L. crispatus DNA (6% vs. 89%, p = .02), a higher load and relative abundance of L. iners DNA (1.1 × 107 copies DNA/mL vs. 8.2 × 105 copies DNA/mL, p = .04; 91% vs. 35%, p = .04), and higher loads of G. vaginalis DNA (7.6 × 104 copies DNA/mL vs. 3.2 × 102 copies DNA/mL, p = .02) than those with cone length < 18 mm.

CONCLUSIONS

A history of cervical excisional treatment was associated with alterations in the cervical microbiota composition in pregnant women with PPROM.

The safety, acceptability, and success rates of amniocentesis in the context of preterm prelabor rupture of membranes and threatened preterm labor: a systematic review and meta-analysis

INTRODUCTION

Preterm birth, defined as birth before 37 weeks of gestation, is the leading cause of death of children under the age of five years worldwide. Globally there has been no change in the preterm birth rate between 2010 and 2020, when rates were calculated to be 9.8% and 9.9% of all livebirths, respectively. The analysis of amniotic fluid has been advocated by many to identify the mechanisms driving threatened preterm labor. Amniocentesis is largely considered to be safe, but care provider concerns about complications in the setting of threatened preterm labor (tPTL) exist. This systematic review will critically review the data regarding safety and outcomes of amniocentesis in cases of PPROM and tPTL and help in the counseling and clinical decision-making of patients and care providers alike.

METHODS

This systematic review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA). All English language, peer-reviewed human studies where amniocentesis was used to sample the amniotic fluid of patients presenting with tPTL or PPROM and published between January 1990 and March 2022 were included. Data on the uptake rates, success rates, and safety profile associated with amniocentesis in this context of tPTL or PPROM were analyzed as part of the systematic review. Included studies compromised of randomized control trials, cohort studies, and case-control studies. Conference abstracts and abstracts with no full text were excluded.

RESULTS

10,215 studies were returned after searches were conducted in MEDLINE, EMBASE, EMCARE, Web of Science, and SCOPUS databases using free text and Medical Subject Headings (MESH). 399 studies were assessed for eligibility with 15 studies being included in the final review. The main reason for exclusion from the review was an absence of safety data. Four studies gave information on uptake rates of amniocentesis in cases of PPROM and tPTL, with a range of 55% in an observational study to >99% in centers offering it as part of routine care. Eleven studies detailed success rates of amniocentesis, with all centers reporting >90% success rates. However, in some centers, a "successful" amniocentesis was deemed to be a retrieval of >0.5 ml. Three studies reported risks associated with amniocentesis. There were four reported complications (all transitory) in a series of 1119 cases (0.35%).

DISCUSSION

This systematic review found that amniocentesis in cases of PPROM or threatened preterm labor is a safe and feasible procedure. These data should give care providers confidence to counsel patients appropriately.

Angiogenic imbalance in pregnancies with preterm prelabor rupture of membranes between 34 and 37 weeks of gestation

INTRODUCTION

This study aimed to identify whether microbial invasion of the amniotic cavity and/or intra-amniotic inflammation in women with late preterm prelabor rupture of membranes (PPROM) was associated with changes in concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and its ratio in maternal serum, and whether placental features consistent with maternal vascular malperfusion further affect their concentrations.

MATERIAL AND METHODS

This historical study included 154 women with singleton pregnancies complicated by PPROM between gestational ages 34+0 and 36+6 weeks. Transabdominal amniocentesis was performed as part of standard clinical management to evaluate the intra-amniotic environment. Women were categorized into two subgroups based on the presence of microorganisms and/or their nucleic acids in amniotic fluid (determined by culturing and molecular biology method) and intra-amniotic inflammation (by amniotic fluid interleukin-6 concentration evaluation): (1) those with the presence of microorganisms and/or inflammation (at least one present) and (2) those with negative amniotic fluid for infection/inflammation (absence of both). Concentrations of sFlt-1 and PlGF were assessed using the Elecsys® sFlt-1 and Elecsys® PlGF immunoassays and converted into multiples of medians.

RESULTS

Women with the presence of microorganisms and/or inflammation in amniotic fluid had lower serum concentrations of sFlt-1 and sFlt-1/PlGF ratios and higher concentrations of PlGF compared with those with negative amniotic fluid. (sFlt-1: presence: median 1.0 multiples of the median (MoM), vs negative: median: 1.5 MoM, P = 0.003; PlGF: presence: median 0.7 MoM, vs negative: median 0.4 MoM, P = 0.02; sFlt-1/PlGF: presence: median 8.9 vs negative 25.0, P = 0.001). Higher serum concentrations of sFlt-1 and sFlt-1/PlGF ratios as well as lower concentrations of PlGF were found in the subsets of women with maternal vascular malperfusion than in those without maternal vascular malperfusion.

CONCLUSIONS

Among women experiencing late PPROM, angiogenic imbalance in maternal serum is primarily observed in those without both microbial invasion of the amniotic cavity and intra-amniotic inflammation. Additionally, there is an association between angiogenic imbalance and the presence of maternal vascular malperfusion.

Characterizing of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta marked by elevated amniotic fluid interferon gamma-induced protein 10 (IP-10) in pregnancies complicated by preterm prelabor rupture of membranes

OBJECTIVES

This study aimed to determine the occurrence of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta, marked by elevated levels of interferon gamma-induced protein 10 (IP-10) (≥2200 pg/mL) in the amniotic fluid of women with preterm prelabor rupture of membranes (PPROM). Specifically, the study investigated whether these intra-amniotic inflammatory changes were more common in women with microbial invasion of amniotic cavity (MIAC) and intra-amniotic inflammation (IAI), as indicated by increased amniotic fluid interleukin (IL)-6 concentration (≥3000 pg/mL).

STUDY DESIGN

A cohort of 114 women with singleton pregnancies complicated by PPROM between 24+0 and 36+6 weeks of gestation were included. Amniotic fluid samples were obtained via amniocentesis upon admission. MIAC diagnosis involved aerobic and anaerobic cultures, as well as polymerase chain reaction (PCR) analysis of the amniotic fluid. Immunoassay tests and enzyme-linked immunosorbent assay (ELISA) were used to determine IL-6 and IP-10 concentrations, respectively.

RESULTS

Among the participants, 19.3 % and 15.8 % had MIAC and IAI, respectively. The occurrence of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta was similar between women with and without MIAC (25 % vs. 40.9 %, p = 0.136, adjusted p = 0.213). The rate of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta was significantly higher in women with IAI compared to those without, after adjusting for gestational age at sampling (55.6 % vs. 22.9 %, p = 0.005, adjusted p = 0.011).

CONCLUSION

This study revealed comparable rates of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta in women with and without MIAC, but a higher prevalence of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta in women with IAI. These findings suggest involvement of chronic inflammation even in women with PPROM with acute intra-amniotic inflammation.

Antibiotic treatment reduces the intensity of intraamniotic inflammation in pregnancies with idiopathic vaginal bleeding in the second trimester of pregnancy

BACKGROUND

Idiopathic bleeding in the second trimester of pregnancy complicates <1% of all pregnancies. This pregnancy complication can be caused by alterations in local hemostasis in the decidua due to infection/inflammation in the choriodecidual niche. This condition is associated with intraamniotic inflammatory complications. Antibiotic therapy effectively reduces the intensity of intraamniotic inflammation in certain pregnancy pathologies. However, whether antibiotic administration can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with idiopathic bleeding during the second trimester of pregnancy remains unclear.

OBJECTIVE

This study primarily aimed to determine whether antimicrobial agents can reduce the magnitude of intraamniotic inflammation in patients with idiopathic bleeding in the second trimester of pregnancy by assessing the concentration of interleukin-6 in the amniotic fluid before and after 7 days of antibiotic treatment. The secondary aim was to determine whether treatment with a combination of antibiotics altered the microbial load of Ureaplasma species DNA in amniotic fluid.

STUDY DESIGN

This retrospective cohort study included singleton-gestation patients with idiopathic bleeding between 15+0 and 27+6 weeks who underwent transabdominal amniocentesis at the time of admission. Follow-up amniocentesis was performed in a subset of patients unless abortion or delivery occurred earlier. Concentrations of interleukin-6 were measured in the amniotic fluid samples, and the presence of microbial invasion of the amniotic cavity was assessed using culture and molecular microbiological methods. Intraamniotic inflammation was defined as an interleukin-6 concentration ≥3000 pg/mL in the amniotic fluid samples.

RESULTS

A total of 36 patients with idiopathic bleeding in the second trimester of pregnancy were included. All the patients underwent initial amniocentesis. Patients with intraamniotic inflammation (n=25) were treated using a combination of antibiotics consisting of intravenous ceftriaxone, intravenous metronidazole, and peroral clarithromycin. The patients without intraamniotic inflammation (n=11) were treated expectantly. In total, 25 patients delivered 7 days after admission. All patients with intraamniotic inflammation at the initial amniocentesis who delivered after 7 days underwent follow-up amniocentesis. Treatment with antibiotics decreased the interleukin-6 concentration in the amniotic fluid at follow-up amniocentesis compared with that at the initial amniocentesis in patients with intraamniotic inflammation (median [interquartile range]: 3457 pg/mL [2493-13,203] vs 19,812 pg/mL [11,973-34,518]; P=.0001). Amniotic fluid samples with Ureaplasma species DNA had a lower microbial load at the time of follow-up amniocentesis compared with the initial amniocentesis (median [interquartile range]: 1.5×105 copies DNA/mL [1.3×105-1.7×105] vs 8.0×107 copies DNA/mL [6.7×106-1.6×108]; P=.02).

CONCLUSION

Antibiotic therapy was associated with reduced intraamniotic inflammation in patients with idiopathic bleeding in the second trimester complicated by intraamniotic inflammation. Moreover, antibiotic treatment has been associated with a reduction in the microbial load of Ureaplasma species DNA in the amniotic fluid.

Cervical excisional treatment increases the risk of intraamniotic infection in subsequent pregnancy complicated by preterm prelabor rupture of membranes

BACKGROUND

Excisional treatment of cervical intraepithelial neoplasia or very early stages of cervical cancer increases the risk of preterm prelabor rupture of membranes in subsequent pregnancies. The risk increases with the length of the excised cone. The subset of cases with preterm prelabor rupture of membranes and a history of cervical excisional treatment could also be at higher risk of intraamniotic infection/inflammation. However, there is a paucity of relevant information on this subject.

OBJECTIVE

This study aimed to assess the differences in the rates of intraamniotic infection/inflammation and early-onset neonatal sepsis between singleton preterm prelabor rupture of membranes pregnancies without and with a history of cervical excisional treatment, and to investigate the association between these complications of preterm prelabor rupture of membranes and the excised cone length.

STUDY DESIGN

This retrospective cohort study included 770 preterm prelabor rupture of membranes pregnancies in which transabdominal amniocentesis was performed as part of standard clinical management to assess the intraamniotic environment. The maternal and perinatal medical records of all included women were reviewed to obtain information on the absence or presence of history of cervical excisional treatment and neonatal outcomes. Women whose records contained any information on history of cervical excisional treatment were contacted by phone and in writing to inform them of the study and request permission to collect relevant information from their medical records. Women were divided into 4 subgroups according to the presence of microorganisms and/or their nucleic acids (through culturing and molecular biology methods) in amniotic fluid and/or intraamniotic inflammation (through amniotic fluid interleukin-6 concentration evaluation): intraamniotic infection (presence of both), sterile intraamniotic inflammation (intraamniotic inflammation alone), microbial invasion of the amniotic cavity without inflammation (presence of microorganisms and/or their nucleic acids in amniotic fluid alone), and negative amniotic fluid for infection/inflammation (absence of both).

RESULTS

A history of cervical excisional treatment was found in 10% (76/765) of the women. Of these, 82% (62/76) had a history of only 1 treatment, and information on cone length was available for 97% (60/62) of them. Women with a history of cervical excisional treatment had higher rates of intraamniotic infection (with, 25% [19/76] vs without, 12% [85/689]; adjusted odds ratio, 2.5; adjusted P=.004), microbial invasion of the amniotic cavity without inflammation (with, 25% [19/76] vs without, 11% [74/689]; adjusted odds ratio, 3.1; adjusted P<.0001), and early-onset neonatal sepsis (with, 8% [11/76] vs without, 3% [23/689]; adjusted odds ratio, 2.9; adjusted P=.02) compared with those without such history. Quartiles of cone length (range: 3-32 mm) were used to categorize the women into 4 quartile subgroups (first: 3-8 mm; second: 9-12 mm; third: 13-17 mm; and fourth: 18-32 mm). Cone length of ≥18 mm was associated with higher rates of intraamniotic infection (with, 29% [5/15] vs without, 12% [85/689]; adjusted odds ratio, 3.0; adjusted P=.05), microbial invasion of the amniotic cavity without inflammation (with, 40% [6/15] vs without, 11% [74/689]; adjusted odds ratio, 6.1; adjusted P=.003), and early-onset neonatal sepsis (with, 20% [3/15] vs without, 3% [23/689]; adjusted odds ratio, 5.7; adjusted P=.02).

CONCLUSION

History of cervical excisional treatment increases risks of intraamniotic infection, microbial invasion of the amniotic cavity without inflammation, and development of early-onset neonatal sepsis in a subsequent pregnancy complicated by preterm prelabor rupture of membranes.

Prevalence and Load of Cervical Ureaplasma Species With Respect to Intra-amniotic Complications in Women With Preterm Prelabor Rupture of Membranes Before 34 weeks

Objectives: To determine the prevalence and load of Ureaplasma spp. DNA in the cervical fluid of women with singleton pregnancies complicated by preterm prelabor rupture of membranes (PPROM) with respect to intra-amniotic infection, sterile intra-amniotic inflammation, and colonization of the amniotic fluid.

Methods: A total of 217 women with PPROM between gestational ages 24 + 0 and 33 + 6 weeks were included in this study. Paired amniotic and cervical fluid samples were collected at the time of admission via transabdominal amniocentesis and using a Dacron polyester swab, respectively. Microbial invasion of the amniotic cavity was diagnosed using a combination of culture and molecular biology methods. Intra-amniotic inflammation was determined based on the concentration of interleukin-6 in the amniotic fluid. Based on the presence or absence of these conditions, the women were stratified into the following subgroups: intra-amniotic infection (with both), sterile intra-amniotic inflammation (with inflammation only), colonization (with microorganisms only), and negative amniotic fluid (without either). The Ureaplasma spp. DNA load in the cervical fluid was assessed using PCR.

Results:Ureaplasma spp. DNA in the cervical fluid was found in 61% (133/217) of the women. Women with negative amniotic had similar prevalence of Ureaplasma spp. DNA in cervical fluid (55%) to those with sterile intra-amniotic inflammation (54%) but lower than those with intra-amniotic infection (73%) and colonization (86%; p < 0.0001). Women with negative amniotic fluid had a lower load of Ureaplasma spp. DNA in their cervical fluid (median: 4.7 × 10³ copies of DNA/ml) than those with intra-amniotic infection (median: 2.8 × 10⁵ copies DNA/ml), sterile intra-amniotic inflammation (median: 5.3 × 10⁴ copies DNA/ml), and colonization (median: 1.2 × 10⁵ copies DNA/mL; p < 0.0001).

Conclusion: In conclusion, in PPROM at <34 weeks, the presence of intra-amniotic infection, sterile intra-amniotic inflammation, or colonization of the amniotic fluid was associated with a higher prevalence and/or load of Ureaplasma spp. DNA in the cervical fluid than the absence of intra-amniotic complications.

Clinical characteristics of colonization of the amniotic cavity in women with preterm prelabor rupture of membranes, a retrospective study

To determine the main clinical characteristics of preterm prelabor rupture of membranes (PPROM) complicated by colonization of the amniotic cavity (microbial invasion of the amniotic cavity without intra-amniotic inflammation). A total of 302 women with PPROM were included. Transabdominal amniocentesis was performed and amniotic fluid was assessed. Based of microbial invasion of the amniotic cavity and intra-amniotic inflammation (interleukin-6 ≥ 3000 pg/mL), the women were divided into following groups: intra-amniotic infection, sterile intra-amniotic inflammation, colonization of the amniotic cavity, and negative amniotic fluid. Colonization was found in 11% (32/302) of the women. The most common bacteria identified in the amniotic fluid were Ureaplasma spp. with a lower burden than those with intra-amniotic infection (p = 0.03). The intensity of intra-amniotic inflammatory response measured by interleukin-6 was higher in women with colonization than in those with negative amniotic fluid (medians: 961 pg/mL vs. 616 pg/mL; p = 0.04). Women with colonization had higher rates of acute inflammatory placental lesions than those with negative amniotic fluid. In PPROM, colonization, caused mainly by microorganisms from the lower genital tract, might represent an early stage of microbial invasion of the amniotic cavity with a weak intra-amniotic inflammatory response.

Breaking Down the Barrier: The Role of Cervical Infection and Inflammation in Preterm Birth

Approximately 40% of cases of spontaneous preterm birth (sPTB) are associated with ascending intrauterine infections. The cervix serves as a physical and immunological gatekeeper, preventing the ascent of microorganisms from the vagina to the amniotic cavity. The cervix undergoes remodeling during pregnancy. It remains firm and closed from the start until the late third trimester of pregnancy and then dilates and effaces to accommodate the passage of the fetus during delivery. Remodeling proceeds appropriately and timely to maintain the pregnancy until term delivery. However, risk factors, such as acute and chronic infection and local inflammation in the cervix, may compromise cervical integrity and result in premature remodeling, predisposing to sPTB. Previous clinical studies have established bacterial (i.e., chlamydia, gonorrhea, mycoplasma, etc.) and viral infections (i.e., herpesviruses and human papillomaviruses) as risk factors of PTB. However, the exact mechanism leading to PTB is still unknown. This review focuses on: (1) the epidemiology of cervical infections in pregnant patients; (2) cellular mechanisms that may explain the association of cervical infections to premature cervical ripening and PTB; (3) endogenous defense mechanisms of the cervix that protect the uterine cavity from infection and inflammation; and (4) potential inflammatory biomarkers associated with cervical infection that can serve as prognostic markers for premature cervical ripening and PTB. This review will provide mechanistic insights on cervical functions to assist in managing cervical infections during pregnancy.

Birth weight and intra-amniotic inflammatory and infection-related complications in pregnancies with preterm prelabor rupture of membranes: a retrospective cohort study

OBJECTIVE

To assess the association between the birth weight of newborns and microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation in pregnancies with preterm prelabor rupture of membranes.

METHODS

A total of 528 pregnancies with preterm prelabor rupture of membranes were included in this retrospective cohort study. Transabdominal amniocentesis to determine the presence of MIAC (through culturing and molecular biology methods) and intra-amniotic inflammation (according to amniotic fluid interleukin-6 level) was performed as part of standard clinical management. Based on the presence of MIAC and/or intra-amniotic inflammation, the participants were divided into four subgroups: with intra-amniotic infection (presence of both), with sterile IAI (intra-amniotic inflammation alone), with colonization (MIAC alone), and with negative amniotic fluid (absence of both). Birth weights of newborns are expressed as percentiles derived from INTERGROWTH-21st standards for (i) newborn birth weight and (ii) estimated fetal weight.

RESULTS

No differences in birth weights, expressed as percentiles derived from newborn weight standards (infection: median 52; sterile: median 54; colonization: median 50; negative amniotic fluid: median 51; p = .93) and estimated fetal weight standards (infection: median 47; sterile: median 51; colonization: median 47; negative amniotic fluid: median 53; p = .48) were found among the four subgroups. No differences in percentiles (derived from both standards) were found in the subset of participants who delivered within 72 h after rupture of membranes (newborn weight standard, p = .99; estimated fetal weight standard, p = .81).

CONCLUSIONS

No association was identified between the birth weight of newborns and the presence of intra-amniotic inflammatory and infection-related complications in pregnancies with preterm prelabor rupture of membranes.

Intra-amniotic infection and sterile intra-amniotic inflammation in women with preterm labor with intact membranes are associated with a higher rate of Ureaplasma species DNA presence in the cervical fluid

OBJECTIVE

To determine the prevalence of Ureaplasma spp. DNA and its load in the cervical fluid in women with preterm labor with intact membranes (PTL) complicated by intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation) or sterile intra-amniotic inflammation (the presence of intra-amniotic inflammation alone).

METHODS

Overall, 115 women with singleton pregnancies complicated by PTL between gestational ages of 22 + 0 and 34 + 6 weeks were included in this study. Paired amniotic and cervical fluid samples were collected at the time of admission via transabdominal amniocentesis using a Dacron polyester swab. Microbial invasion of the amniotic cavity was diagnosed based on a combination of culture and molecular biology methods. Intra-amniotic inflammation was determined based on the concentration of interleukin-6 in the amniotic fluid. Bacterial and Ureaplasma spp. DNA loads were assessed in the cervical fluid using PCR.

RESULTS

Intra-amniotic infection and sterile inflammation were identified in 14% (16/115) and 25% (29/115) of the women, respectively. Ureaplasma spp. DNA in the cervical fluid was identified in 51% (59/115) of women. The presence of Ureaplasma spp. DNA in the cervical fluid was higher in women with intra-amniotic infection (75% (12/16)) and sterile intra-amniotic inflammation (76% (22/29)) than in women without intra-amniotic inflammation (36% (25/70); p = .0002). Concurrent presence of Ureaplasma spp. and Mycoplasma hominis DNA was higher in women with intra-amniotic infection (42% (5/12)) than women with sterile intra-amniotic inflammation (7% (2/29)) and women without intra-amniotic inflammation (7% (5/70); p = .001). There were no differences in the load of Ureaplasma spp. DNA in the cervical fluid among women with intra-amniotic infection, sterile intra-amniotic inflammation, and those without intra-amniotic inflammation (median values; infection: 1.2 × 10⁴ copies DNA/mL; sterile: 5.0 × 10⁵ copies DNA/mL; without: 8.4 × 10⁴ copies DNA/mL; p = .18).

CONCLUSIONS

In PTL , both forms of intra-amniotic inflammation were associated with a higher prevalence of Ureaplasma spp. DNA in the cervical fluid. The presence of intra-amniotic infection was related to a higher rate of concurrent Ureaplasma spp. and M. hominis DNA in the cervical fluid.

Prenatal inflammation as a link between placental expression signature of tryptophan metabolism and preterm birth

Spontaneous preterm birth is a serious medical condition responsible for substantial perinatal morbidity and mortality. Its phenotypic characteristics, preterm labor with intact membranes (PTL) and preterm premature rupture of the membranes (PPROM), are associated with significantly increased risks of neurological and behavioral alterations in childhood and later life. Recognizing the inflammatory milieu associated with PTL and PPROM, here, we examined expression signatures of placental tryptophan metabolism, an important pathway in prenatal brain development and immunotolerance. The study was performed in a well-characterized clinical cohort of healthy term pregnancies (n = 39) and 167 preterm deliveries (PTL, n = 38 and PPROM, n = 129). Within the preterm group, we then investigated potential mechanistic links between differential placental tryptophan pathway expression, preterm birth and both intra-amniotic markers (such as amniotic fluid interleukin-6) and maternal inflammatory markers (such as maternal serum C-reactive protein and white blood cell count). We show that preterm birth is associated with significant changes in placental tryptophan metabolism. Multifactorial analysis revealed similarities in expression patterns associated with multiple phenotypes of preterm delivery. Subsequent correlation computations and mediation analyses identified links between intra-amniotic and maternal inflammatory markers and placental serotonin and kynurenine pathways of tryptophan catabolism. Collectively, the findings suggest that a hostile inflammatory environment associated with preterm delivery underlies the mechanisms affecting placental endocrine/transport functions and may contribute to disruption of developmental programming of the fetal brain.

Vertical transmission potential of SARS-CoV-2 from infected mother to twin neonates

Background: Limited details are available regarding the vertical transmission potential of COVID-19 infection in pregnant women. The authors' current study aimed to report the vertical transmission potential of COVID-19 infection in a woman pregnant with twins. Case description: The authors report the case of a 27-year-old woman infected with SARS-CoV-2. The patient was pregnant with dichorionic diamniotic fraternal twins and admitted to Renmin Hospital of Wuhan University, Wuhan, China. After undergoing a cesarean section, the patient gave birth to premature twins, who tested positive for COVID-19 infection. Interpretation: Findings from this case suggest a possibility of intrauterine infection caused by vertical transmission in a woman infected with COVID-19.

Intra-amniotic inflammatory complications in preterm prelabor rupture of membranes and long-term neurodevelopmental outcomes of infants: a systematic review

OBJECTIVE

To perform a systematic review of the literature available on the association between the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation and long-term neurodevelopmental outcomes of infants from pregnancies complicated by preterm prelabor rupture of membranes (PPROM).

METHODS

A literature search, from their earliest entries to May 2020, was performed by employing three electronic databases (Web of Science, PubMed, and Scopus). The selection criteria were as follows: (1) singleton pregnancies with PPROM; (2) available information regarding MIAC and/or intra-amniotic inflammation; (3) long-term (at least one year of the corrected age) neurodevelopmental outcomes of respective infants.

RESULTS

The initial search identified 10,953 articles, of which 8 were selected for full-text reading; however, none were included in the review owing to the following reasons: (i) spontaneous preterm labor with intact membranes and/or indicated (iatrogenic) preterm delivery were included in the studies without providing separate data for PPROM (n = 5); (ii) long-term, at least one year of the corrected age, neurodevelopmental outcomes of infants were not assessed (n = 1); (iii) the presence of both the abovementioned reasons (n = 1); (iv) amniotic fluid was not assessed, and a long-term neurodevelopmental outcome was not evaluated (n = 1).

CONCLUSION

The literature search provides evidence of a knowledge gap in the association between the presence of MIAC and/or intra-amniotic inflammation and long-term neurodevelopmental outcomes in infants with PPROM.

Gut and Reproductive Tract Microbiota Adaptation during Pregnancy: New Insights for Pregnancy-Related Complications and Therapy

Pregnancy is characterized by maternal adaptations that are necessary to create a welcoming and hospitable environment for the fetus. Studies have highlighted how the microbiota modulates several networks in humans through complex molecular interactions and how dysbiosis (defined as quantitative and qualitative alterations of the microbiota communities) is related to human pathologies including gynecological diseases. This review analyzed how maternal uterine, vaginal, and gut microbiomes could impact on fetus health during the gestational period. We evaluated the role of a dysbiotic microbiota in preterm birth, chorioamnionitis, gestational diabetes mellitus and pre-eclampsia. For many years it has been hypothesized that newborns were sterile organisms but in the past few years this paradigm has been questioned through the demonstration of the presence of microbes in the placenta and meconium. In the future, we should go deeper into the concept of in utero colonization to better understand the role of microbiota through the phases of pregnancy. Numerous studies in the literature have already showed interesting results regarding the role of microbiota in pregnancy. This evidence gives us the hope that microbiota modulation could be a novel strategy to reduce the morbidity and mortality related to pregnancy complications in the future.

Cervical Gardnerella vaginalis in women with preterm prelabor rupture of membranes

Objective

To determine the association between microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI) and the cervical prevalence of Gardnerella vaginalis DNA in pregnancies with preterm prelabor rupture of membrane (PPROM).

Method

In total, 405 women with singleton pregnancies complicated with PPROM were included. Cervical fluid and amniotic fluid samples were collected at the time of admission. Bacterial and G. vaginalis DNA were assessed in the cervical fluid samples using quantitative PCR technique. Concentrations of interleukin-6 and MIAC were evaluated in the amniotic fluid samples. Loads of G. vaginalis DNA ≥ 1% of the total cervical bacterial DNA were used to define the cervical prevalence of G. vaginalis as abundant. Based on the MIAC and IAI, women were categorized into four groups: with intra-amniotic infection (both MIAC and IAI), with sterile IAI (IAI without MIAC), with MIAC without IAI, and without either MIAC or IAI.

Results

The presence of the abundant cervical G. vaginalis was related to MIAC (with: 65% vs. without: 44%; p = 0.0004) but not IAI (with: 52% vs. without: 48%; p = 0.70). Women with MIAC without IAI had the highest load of the cervical G. vaginalis DNA (median 2.0 × 10⁴ copies DNA/mL) and the highest presence of abundant cervical G. vaginalis (73%).

Conclusions

In women with PPROM, the presence of cervical G. vaginalis was associated with MIAC, mainly without the concurrent presence of IAI.

Comprehensive proteomic investigation of infectious and inflammatory changes in late preterm prelabour rupture of membranes

Preterm prelabour rupture of membranes beyond the 34th week of gestation (late PPROM) is frequently associated with the risk of the microbial invasion of the amniotic fluid (MIAC) and histological chorioamnionitis (HCA). Hence, we employed a Tandem Mass Tag-based approach to uncover amniotic fluid proteome response to the presence of MIAC and HCA in late PPROM. Protein dysregulation was associated with only five cases in the group of 15 women with confirmed MIAC and HCA. Altogether, 138 amniotic fluid proteins were changed in these five cases exclusively. These proteins were particularly associated with excessive neutrophil responses to infection, such as neutrophil degranulation and extracellular trap formation. We believe that the quantification of these proteins in amniotic fluid may assist in revealing women with the highest risk of excessive inflammatory response in late PPROM.

Extracellular granzyme A in amniotic fluid is elevated in the presence of sterile intra-amniotic inflammation in preterm prelabor rupture of membranes

INTRODUCTION

To determine the levels of granzyme A in amniotic fluid in pregnancies complicated by preterm prelabor rupture of membranes (PPROM), based on the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI).

METHODS OF STUDY

A total of 166 women with singleton pregnancies complicated by PPROM were included. Amniocentesis was performed at the time of admission and assessments of MIAC (using both cultivation and non-cultivation techniques) and IAI (interleukin-6 in amniotic fluid) were performed on all subjects. Based on the presence/absence of MIAC and IAI, the women were further divided into the following subgroups: intra-amniotic infection, sterile IAI, colonization, and absence of both MIAC and IAI. Amniotic fluid granzyme A levels were assessed using ELISA.

RESULTS

Women with MIAC had lower levels of granzyme A in the amniotic fluid than women without this condition (with MIAC: median 15.9 pg/mL vs. without MIAC: median 19.9 pg/mL, p = .03). Women with sterile IAI had higher amniotic fluid granzyme A levels than women with intra-amniotic infection, colonization and women with the absence of either MIAC or IAI (intra-amniotic infection: median 15.6 pg/mL; sterile IAI: median 31.8 pg/mL; colonization: median 16.9 pg/mL; absence of both MIAC and IAI: median 18.8 pg/mL; p = .02).

CONCLUSIONS

The presence of sterile IAI was associated with elevated levels of granzyme A in amniotic fluid.

Tumor microbial diversity and compositional differences among women in Botswana with high-grade cervical dysplasia and cervical cancer

INTRODUCTION

We characterized the cervical 16S rDNA microbiome of patients in Botswana with high-grade cervical dysplasia and locally advanced cervical cancer.

METHODS

This prospective study included 31 patients: 21 with dysplasia and 10 with cancer. The Shannon diversity index was used to evaluate alpha (intra-sample) diversity, while the UniFrac (weighted and unweighted) and Bray-Curtis distances were employed to evaluate beta (inter-sample) diversity. The relative abundance of microbial taxa was compared among samples using linear discriminant analysis effect size.

RESULTS

Alpha diversity was significantly higher in patients with cervical cancer than in patients with cervical dysplasia (P<0.05). Beta diversity also differed significantly (weighted UniFrac Bray-Curtis, P<0.01). Neither alpha diversity (P=0.8) nor beta diversity (P=0.19) varied by HIV status. The results of linear discriminant analysis effect size demonstrated that multiple taxa differed significantly between patients with cervical dysplasia vs cancer. Lachnospira bacteria (in the Clostridia class) were particularly enriched among cervical dysplasia patients, while Proteobacteria (members of the Firmicutes phyla and the Comamonadaceae family) were enriched in patients with cervical cancer.

DISCUSSION

The results of our study suggest that differences exist in the diversity and composition of the cervical microbiota between patients with cervical dysplasia and patients with cervical cancer in Botswana. Additional studies are warranted to validate these findings and elucidate their clinical significance among women living in sub-Saharan Africa, as well as other regions of the world.

Factors affecting early-life intestinal microbiota development

OBJECTIVES

This paper reviews the published evidence on early-life intestinal microbiota development, as well as the different factors influencing its development before, at, and after birth. A literature search was done using PubMed, Cochrane and EMBASE databases. A growing body of evidence indicates that the intrauterine environment is not sterile as once presumed, but that maternal-fetal transmission of microbiota occurs during pregnancy. The consecutive order of bacteria with which the gastrointestinal tract is colonized will influence the outcome of community assembly and the ecological success of individual colonizers. The genetic background of the infant may also strongly influence microbial colonization of the gastrointestinal tract. The composition and development of infant gut microbiota can be influenced by many prenatal factors, such as maternal diet, obesity, smoking status, and use of antibiotic agents during pregnancy. Mode of delivery is generally accepted as a major factor determining the initial colonization. Breast milk stimulates the most balanced microbiome development for the infant, mainly because of its high content of unique oligosaccharides. Feeding is another important factor to determine intestinal colonization. Compared with breastfed infants, formula-fed infants have an increased richness of species. Initial clinical studies show that infant formulas supplemented with specific human milk oligosaccharides (HMOs) -2´-fucosyllactose alone or in combination with lacto-n-neotetraose are structurally identical to those in breast milk. HMOs increase the proportion of infants with a high bifidobacterial-dominated gut microbiota typical of that observed in breastfed infants, lead to plasma immune marker profiles similar to those of breast-fed infants and to lower morbidity and antibiotics use. Further clinical studies with the same, others or more HMOs are needed to confirm these clinical effects. A growing number of studies have reported on how the composition and development of the microbiota during early life will affect risk factors related to health up to and during adulthood. If exclusive breastfeeding is not possible, the composition of infant formula should be adapted to stimulate the development of a bifidobacterial-dominated gut microbiota typical of that observed in breastfed infants. The main components in breast milk that stimulate the growth of specific bifidobacteria are HMOs.