Commentary on a combined approach to the problem of developing biomarkers for the prediction of spontaneous preterm labor that leads to preterm birth.

INTRODUCTION: Globally, preterm birth has replaced congenital malformation as the major cause of perinatal mortality and morbidity. The reduced rate of congenital malformation was not achieved through a single biophysical or biochemical marker at a specific gestational age, but rather through a combination of clinical, biophysical and biochemical markers at different gestational ages. Since the aetiology of spontaneous preterm birth is also multifactorial, it is unlikely that a single biomarker test, at a specific gestational age will emerge as the definitive predictive test. METHODS: The Biomarkers Group of PREBIC, comprising clinicians, basic scientists and other experts in the field, with a particular interest in preterm birth have produced this commentary with short, medium and long-term aims: i) to alert clinicians to the advances that are being made in the prediction of spontaneous preterm birth; ii) to encourage clinicians and scientists to continue their efforts in this field, and not to be disheartened or nihilistic because of a perceived lack of progress and iii) to enable development of novel interventions that can reduce the mortality and morbidity associated with preterm birth. RESULTS: Using language that we hope is clear to practising clinicians, we have identified 11 Sections in which there exists the potential, feasibility and capability of technologies for candidate biomarkers in the prediction of spontaneous preterm birth and how current limitations to this research might be circumvented. DISCUSSION: The combination of biophysical, biochemical, immunological, microbiological, fetal cell, exosomal, or cell free RNA at different gestational ages, integrated as part of a multivariable predictor model may be necessary to advance our attempts to predict sPTL and PTB. This will require systems biological data using "omics" data and artificial intelligence/machine learning to manage the data appropriately. The ultimate goal is to reduce the mortality and morbidity associated with preterm birth.

Prophylactic incisional negative pressure wound therapy reduces the risk of surgical site infection after caesarean section in obese women: a pragmatic randomised clinical trial.

OBJECTIVE: To evaluate the reduction of surgical site infections by prophylactic incisional negative pressure wound therapy compared with standard postoperative dressings in obese women giving birth by caesarean section. DESIGN: Multicentre randomised controlled trial. SETTING: Five hospitals in Denmark. POPULATION: Obese women (prepregnancy body mass index (BMI) ≥30 kg/m2 ) undergoing elective or emergency caesarean section. METHOD: The participants were randomly assigned to incisional negative pressure wound therapy or a standard dressing after caesarean section and analysed by intention-to-treat. Blinding was not possible due to the nature of the intervention. MAIN OUTCOME MEASURES: The primary outcome was surgical site infection requiring antibiotic treatment within the first 30 days after surgery. Secondary outcomes included wound exudate, dehiscence and health-related quality of life. RESULTS: Incisional negative pressure wound therapy was applied to 432 women and 444 women had a standard dressing. Demographics were similar between groups. Surgical site infection occurred in 20 (4.6%) women treated with incisional negative pressure wound therapy and in 41 (9.2%) women treated with a standard dressing (relative risk 0.50, 95% CI 0.30-0.84; number needed to treat 22; P = 0.007). The effect remained statistically significant when adjusted for BMI and other potential risk factors. Incisional negative pressure wound therapy significantly reduced wound exudate whereas no difference was found for dehiscence and quality of life between the two groups. CONCLUSION: Prophylactic use of incisional negative pressure wound therapy reduced the risk of surgical site infection in obese women giving birth by caesarean section. TWEETABLE ABSTRACT: RCT: prophylactic incisional NPWT versus standard dressings postcaesarean in 876 women significantly reduces the risk of SSI.

Cost-effectiveness of incisional negative pressure wound therapy compared with standard care after caesarean section in obese women: a trial-based economic evaluation.

OBJECTIVE: To evaluate the cost-effectiveness of incisional negative pressure wound therapy (iNPWT) in preventing surgical site infection in obese women after caesarean section. DESIGN: A cost-effectiveness analysis conducted alongside a clinical trial. SETTING: Five obstetric departments in Denmark. POPULATION: Women with a pregestational body mass index (BMI) ≥30 kg/m2 . METHOD: We used data from a randomised controlled trial of 876 obese women who underwent elective or emergency caesarean section and were subsequently treated with iNPWT (n = 432) or a standard dressing (n = 444). Costs were estimated using data from four Danish National Databases and analysed from a healthcare perspective with a time horizon of 3 months after birth. MAIN OUTCOME MEASURES: Cost-effectiveness based on incremental cost per surgical site infection avoided and per quality-adjusted life-year (QALY) gained. RESULTS: The total healthcare costs per woman were €5793.60 for iNPWT and €5840.89 for standard dressings. Incisional NPWT was the dominant strategy because it was both less expensive and more effective; however, no statistically significant difference was found for costs or QALYs. At a willingness-to-pay threshold of €30,000, the probability of the intervention being cost-effective was 92.8%. A subgroup analysis stratifying by BMI shows that the cost saving of the intervention was mainly driven by the benefit to women with a pre-pregnancy BMI ≥35 kg/m2 . CONCLUSION: Incisional NPWT appears to be cost saving compared with standard dressings but this finding is not statistically significant. The cost savings were primarily found in women with a pre-pregnancy BMI ≥35 kg/m2 . TWEETABLE ABSTRACT: Prophylactic incisional NPWT reduces the risk of SSI after caesarean section and is probably dominant compared with standard dressings #healtheconomics.

Meta-analysis of negative-pressure wound therapy for closed surgical incisions.

BACKGROUND: Postoperative wound complications are common following surgical procedures. Negative-pressure wound therapy (NPWT) is well recognized for the management of open wounds and has been applied recently to closed surgical incisions. The evidence base to support this intervention is limited. The aim of this study was to assess whether NPWT reduces postoperative wound complications when applied to closed surgical incisions. METHODS: This was a systematic review and meta-analysis of randomized clinical trials of NPWT compared with standard postoperative dressings on closed surgical incisions. RESULTS: Ten studies met the inclusion criteria, reporting on 1311 incisions in 1089 patients. NPWT was associated with a significant reduction in wound infection (relative risk (RR) 0·54, 95 per cent c.i. 0·33 to 0·89) and seroma formation (RR 0·48, 0·27 to 0·84) compared with standard care. The reduction in wound dehiscence was not significant. The numbers needed to treat were three (seroma), 17 (dehiscence) and 25 (infection). Methodological heterogeneity across studies led to downgrading of the quality of evidence to moderate for infection and seroma, and low for dehiscence. CONCLUSION: Compared with standard postoperative dressings, NPWT significantly reduced the rate of wound infection and seroma when applied to closed surgical wounds. Heterogeneity between the included studies means that no general recommendations can be made yet.

Increasing use of antibiotics in pregnancy during the period 2000-2010: prevalence, timing, category, and demographics.

OBJECTIVE: The aim of this study was to describe the use of antibiotics in a national population-based cohort of pregnant Danish women between 2000 and 2010. DESIGN: Register-based, population-wide, cohort study. SETTING: Denmark, from 2000 to 2010. POPULATION: All pregnancies among Danish residents during the period 2000-2010 were included for analysis. METHODS: Data were obtained from the Danish Medical Birth Registry, the Danish National Patient Registry, and the Registry of Medicinal Product Statistics. The filled prescriptions for systemic antibacterial, antimycotic, and antiviral drugs, as well as intravaginally applied antibiotics, were analysed. Associations with demographic variables were assessed using multivariate analysis. MAIN OUTCOME MEASURES: Filled prescriptions for antibiotic drugs during pregnancy. RESULTS: We included 987 973 pregnancies in Denmark from 2000 to 2010; 38.9% of women with a delivery and 14.8% of women with a miscarriage or termination of pregnancy had one or more antibiotic treatments during pregnancy. Systemic antibacterial drugs were the most frequently used drug group, with filled prescriptions for 33.4% of all deliveries and 12.6% of all abortions. This proportion increased from 28.4% in 2000 to 37.0% in 2010 among deliveries. The biggest change was seen for pivmecillinam, which increased among deliveries from 6.3% in 2000 to 19.5% in 2010. Obese (odds ratio 1.51; 95% CI 1.47-1.56), young (odds ratio 1.35; 95% CI 1.30-1.39), and low-educated women (odds ratio 1.37; 95% CI 1.35-1.1.39) tended to fill more prescriptions of antibiotics during pregnancy. CONCLUSIONS: Overall, the number of women who filled prescriptions of antibiotics increased during the 11-year study period. In 2010, at least 41.5% of all deliveries were exposed to antibiotic therapy during pregnancy.

Infection and antibiotics in the aetiology, prediction and prevention of preterm birth.

Spontaneous preterm labour and delivery is a syndrome comprising diverse pathological pathways that result in labour and delivery before term. It is recognised that multiple pathological processes are involved, and infection has been well studied and firmly established as a cause. Although the molecular mechanisms responsible for this process have been identified, there is a lack of consensus about effective antibiotic intervention. Systematic reviews of the few well conducted studies suggest that antibiotics active against bacterial vaginosis or related organisms (clindamycin) given to appropriate women (those with objective evidence of abnormal genital tract flora), and used early in pregnancy (< 22 completed weeks of gestation) before irreversible inflammatory damage occurs, can reduce the rate of preterm birth. There is a need for well constructed trials to understand the vaginal microbiome and how the different types of maternal immune response influences outcome.

Rescreening for abnormal vaginal flora in pregnancy and re-treating with clindamycin vaginal cream significantly increases cure and improvement rates.

We investigated 199 pregnant women with bacterial vaginosis (BV) who received clindamycin vaginal cream (CVC) for three days and compared with 205 women treated with placebo. The vaginal flora was assessed at each visit. At the second visit, 71% in the CVC group were cured/improved, compared with 12% in the placebo group (P < 0.001). At visit 3 about 90% who responded to initial CVC treatment were still cured/improved. Of women who initially failed to respond to CVC and were given an additional seven-day course, 33% were cured/improved by the third visit, compared with 15% who failed to respond to placebo initially and were given a further seven-day course (P = 0.02). By visit 4, half the women in the CVC group who received additional treatment remained cured/improved, compared with 26% who had additional placebo (P = 0.004). In the CVC group, a change from abnormal to normal rose from 71% (visit 2) to 76% (visit 3) and 79% (visit 4). A similar trend was seen in women who received placebo but the proportions were significantly lower (12%, 24% and 33%, respectively). There is value in rescreening and re-treating women who remain BV-positive after initial clindamycin treatment.

The vaginal microbiome: new information about genital tract flora using molecular based techniques.

Vaginal microbiome studies provide information that may change the way we define vaginal flora. Normal flora appears dominated by one or two species of Lactobacillus. Significant numbers of healthy women lack appreciable numbers of vaginal lactobacilli. Bacterial vaginosis (BV) is not a single entity, but instead consists of different bacterial communities or profiles of greater microbial diversity than is evident from cultivation-dependent studies. BV should be considered a syndrome of variable composition that results in different symptoms, phenotypical outcomes, and responses to different antibiotic regimens. This information may help to elucidate the link between BV and infection-related adverse outcomes of pregnancy.

Mycoplasmas in pregnancy.

The genital mycoplasmas have been implicated in a number of adverse outcomes of pregnancy. Spontaneous preterm labour and preterm birth is an important contributor to perinatal mortality and morbidity. If Mycoplasma hominis plays an integral part in this problem, it is likely to contribute through its involvement with bacterial vaginosis. Ureaplasmas induce cytokines and inflammation, making a casual association compelling. The role of Mycoplasma genitalium and Mycoplasma fermentans is less clear, but M. genitalium is potentially pathogenic and should be treated if detected. There is considerable evidence for the role of M. hominis in post-partum and post-abortal sepsis, and for ureaplasmas causing chronic lung disease or death in very low birthweight infants. The role of the genital mycoplasmas in adverse outcomes of pregnancy is complicated by the presence or absence of bacterial vaginosis, and this association requires further research.

Current debate on the use of antibiotic prophylaxis for caesarean section.

Caesarean delivery is frequently complicated by surgical site infections, endometritis and urinary tract infection. Most surgical site infections occur after discharge from the hospital, and are increasingly being used as performance indicators. Worldwide, the rate of caesarean delivery is increasing. Evidence-based guidelines recommended the use of prophylactic antibiotics before surgical incision. An exception is made for caesarean delivery, where narrow-range antibiotics are administered after umbilical cord clamping because of putative neonatal benefit. However, recent evidence supports the use of pre-incision, broad-spectrum antibiotics, which result in a lower rate of maternal morbidity with no disadvantage to the neonate.

Parvovirus B19 infection in human pregnancy.

Human parvovirus B19 infection is widespread. Approximately 30-50% of pregnant women are nonimmune, and vertical transmission is common following maternal infection in pregnancy. Fetal infection may be associated with a normal outcome, but fetal death may also occur without ultrasound evidence of infectious sequelae. B19 infection should be considered in any case of nonimmune hydrops. Diagnosis is mainly through serology and polymerase chain reaction. Surveillance requires sequential ultrasound and Doppler screening for signs of fetal anaemia, heart failure and hydrops. Immunoglobulins, antiviral and vaccination are not yet available, but intrauterine transfusion in selected cases can be life saving.

A comparison of sexual and reproductive health services provided by genitourinary and family planning clinics for adolescents.

The purpose of the study was to assess the use of sexual and reproductive health services by adolescents aged 15 years and younger. A case-note review was conducted at both a genitourinary medicine clinic and a family planning clinic in Edinburgh, UK. The demographics of the attendees, reasons for attending, risk factors, diagnostic tests undertaken and contraceptive advice given differed between the two clinics. Approximately 73% of attendees with documented responses used alcohol and 21% used recreational drugs, 5% reported self-harm, 25% reported being victims of sexual assault, 13% had a current sexually transmitted infection and 6% of girls had already been pregnant. While this group of young people understand the differences in emphasis between the clinics, adolescents may be intimidated and discouraged from attending or may fail to return, and the combination of overlap, together with omissions in cross-clinic function, suggests that for this age group the services of these clinics should be combined.