Why should preterm births be rising?

Application of anti-fungal vaccines as a tool against emerging anti-fungal resistance

After viruses and bacteria, fungal infections remain a serious threat to the survival and well-being of society. The continuous emergence of resistance against commonly used anti-fungal drugs is a serious concern. The eukaryotic nature of fungal cells makes the identification of novel anti-fungal agents slow and difficult. Increasing global temperature and a humid environment conducive to fungal growth may lead to a fungal endemic or a pandemic. The continuous increase in the population of immunocompromised individuals and falling immunity forced pharmaceutical companies to look for alternative strategies for better managing the global fungal burden. Prevention of infectious diseases by vaccines can be the right choice. Recent success and safe application of mRNA-based vaccines can play a crucial role in our quest to overcome anti-fungal resistance. Expressing fungal cell surface proteins in human subjects using mRNA technology may be sufficient to raise immune response to protect against future fungal infection. The success of mRNA-based anti-fungal vaccines will heavily depend on the identification of fungal surface proteins which are highly immunogenic and have no or least side effects in human subjects. The present review discusses why it is essential to look for anti-fungal vaccines and how vaccines, in general, and mRNA-based vaccines, in particular, can be the right choice in tackling the problem of rising anti-fungal resistance.

Effectiveness and perinatal outcomes of history-indicated, ultrasound-indicated and physical examination-indicated cerclage: a retrospective study

OBJECTIVE

To evaluate the effectiveness and perinatal outcomes of cerclage procedure according to indication.

METHODS

The pregnancy and neonatal outcomes of the patients who underwent cerclage with the diagnosis of cervical insufficiency between January 2016 and December 2020 were retrospectively analyzed. Patients were categorized into three groups: a history-indicated group, an ultrasound-indicated group and a physical examination-indicated group.

RESULTS

Seventy-three patients who underwent cerclage were included in the study. Of these, 41 (56.2%) had history-indicated, 17 (23.3%) had ultrasound-indicated and 15 (20.5%) had physical examination-indicated cerclages. Compared to history- and ultrasound-indicated cerclage group, duration from cerclage to delivery (18.6 ± 6.9 weeks vs 17.8±5.9 weeks vs 11 ± 5.3 weeks, p = 0.003) was significantly lower and delivery < 28 weeks (9.8% vs 5.9% vs 33.3%, p = 0.042) and delivery < 34 weeks of gestation (26.8% vs 11.8% vs 60%, p = 0.009) were significantly higher in physical examination-indicated cerclage group. In physical examination-indicated cerclage, compared with history- and ultrasound-indicated cerclage low birth weight, low APGAR score, neonatal intensive care unit admission and neonatal mortality were higher, although not statistically significant (p > 0.05).

CONCLUSION

Pregnant women who underwent physical examination-indicated cerclage had higher risks for preterm delivery < 28 weeks and < 34 weeks than history- and ultrasound-indicated cerclage.

Therapeutic potential of stem cells for preterm infant brain damage: Can we move from the heterogeneity of preclinical and clinical studies to established therapeutics?

Acquired perinatal brain injuries are a set of conditions that remains a key challenge for neonatologists and that have significant social, emotional and financial implications for our communities. In our perspective article, we will introduce perinatal brain injury focusing specifically on the events leading to brain damage in preterm born infants and outcomes for these infants. Then we will summarize and discuss the preclinical and clinical studies testing the efficacy of stem cells as neuroprotectants in the last ten years in perinatal brain injury. There are no therapies to treat brain damage in preterm born infants and a primary finding from this review is that there is a scarcity of stem cell trials focused on overcoming brain injuries in these infants. Overall, across all forms of perinatal brain injury there is a remarkable heterogeneity in previous and on-going preclinical and clinical studies in terms of the stem cell type, animal models/patient selection, route and time of administration. Despite the quality of many of the studies this variation makes it difficult to reach a valid consensus for future developments. However, it is clear that stem cells (and stem cell derived exosomes) can reduce perinatal brain injury and our field needs to work collectively to refine an effective protocol for each type of injury. The use of standardized stem cell products and testing these products across multiple models of injury will provide a stronger framework for clinical trials development.

The epidemiologic characteristics and associated risk factors of preterm birth from 2004 to 2013 in Taiwan

Background

The rate of preterm birth has been increasing worldwide. Most preterm babies are at an increased risk of central nervous system impairments as well as respiratory and gastrointestinal complications. The aim of this study was to investigate the epidemiologic characteristics of and associated factors contributing to preterm birth in Taiwan.

Methods

Information on obstetric antecedents and risk factors for preterm birth in pregnant women was obtained from the National Health Insurance Research (NHIR) database provided by the Taiwan National Health Research Institute. All live births from 2004 to 2013 in Taiwan were included in this study.

Results

A total of 130,362 live births from 2004 to 2013 were included in this study. Overall, the average annual rate of preterm births increased by 5.3% (from 3.33% in 2004 to 5.11% in 2013). Multiple logistic regression analyses showed that nulliparous women, multifetal pregnancies, advanced mother age, history of preterm birth, history of maternal drug abuse/dependence, and maternal medical complications were positively associated with an increased risk of preterm birth (all p-values< 0.05).

Conclusion

The overall proportion of preterm births increased from 2004 to 2013 in Taiwan. Babies born preterm had a higher risk of developing morbidities and mortalities. The development of a comprehensive program to identify the high-risk group is needed for effective interventions to prevent premature birth.

Intraperitoneal cannabidiol attenuates neonatal germinal matrix hemorrhage-induced neuroinflamation and perilesional apoptosis

Background. As the survival of preterm infants has increased significantly, germinal matrix hemorrhage (GMH) has become an important public health issue. Nevertheless, treatment strategies for the direct neuronal injury are still scarce. The present study aims to analyze the neuroprotective properties of cannabidiol in germinal matrix hemorrhage. Methods. 112 Wistar rat pups (P7) were submitted to an experimental collagenase induced model of GMH. Inflammatory response and neuronal death were analyzed both at the perilesional area as at the distant ipsilateral CA1 hippocampal area. Immunohistochemistry for GFAP and caspase 3 was used. The ipsilateral free water content was assessed for stimation of cerebral edema, and neurodevelopment and neurofunctional tests were conducted. Results. Reduction of reactive astrocytosis was observed both in the perilesional area 24 hours and 14 days after the hemorrhage lesion (p < 0.001) and in the Stratum oriens of the ipsilateral hippocampal CA1 14 days after the hemorrhage lesion (p < 0.05) in the treated groups. Similarly, there was a reduction in the number of Caspase 3-positive astrocytes in the perilesional area in the treated groups 24 hours after the hemorrhage lesion (p < 0.001). Finally, we found a significant increase in the weight of the rats treated with cannabidiol. Conclusion. The treatment of GMH with cannabidiol significantly reduced the number of apoptotic cells and reactive astrocytes in the perilesional area and the ipsilateral hippocampus. In addition, this response was sustained 14 days after the hemorrhage. These results corroborate our hypothesis that cannabidiol is a potential neuroprotective agent in the treatment of germinal matrix hemorrhage.

The trends and associated factors of preterm deliveries from 2001 to 2011 in Taiwan

The rate of preterm birth has been increasing worldwide. Most preterm babies are at increased risk of central nervous system impairments as well as respiratory and gastrointestinal complications. The aim of this study was to investigate the trends in preterm birth and associated factors contributing to preterm delivery in Taiwan. Information on obstetric antecedents and risk factors of preterm birth of pregnant women was obtained from the Taiwan National Medical Birth Register database. All live births from 2001 to 2011 in Taiwan were included in this study. A total of 2,334,532 live births from 2001 to 2011 were included in this study. Overall, the proportion of preterm deliveries increased by 11.1% (from 8.2% in 2001 to 9.1% in 2011). Multiple logistic regression analyses showed that nulliparity, multiple births, maternal medical complications, maternal age <20 years or ≥40 years, and medical indication for earlier delivery were positively associated with an increased risk of preterm delivery. Nulliparous women aged younger than 20 years and older than 40 years should be recognized as at-risk for preterm birth.

Cannabinoid receptor-2 stimulation suppresses neuroinflammation by regulating microglial M1/M2 polarization through the cAMP/PKA pathway in an experimental GMH rat model

Excessive inflammatory responses are involved in secondary brain injury during germinal matrix hemorrhage (GMH). The process of microglial polarization to the pro-inflammatory M1 or anti-inflammatory M2 phenotypes is considered to occur in a major immunomodulatory manner during brain inflammation. We previously found that cannabinoid receptor-2 (CB2R) stimulation attenuated microglial accumulation and brain injury following experimental GMH. However, whether CB2R has effects on microglial polarization after GMH remains unclear. Herein, we investigated the effects of CB2R stimulation on neuroinflammation after experimental GMH and the potential mechanisms that mediate M1/M2 microglial phenotype regulation. The results indicated that during the GMH acute phase, microglia primarily polarized to the M1 phenotype and induced an overwhelming release of pro-inflammatory cytokines. However, JWH133, a selective CB2R agonist, significantly prevented the pro-inflammatory cytokine release while promoting an M1 to M2 phenotype transformation in microglia, resulting in an increased anti-inflammatory cytokine release. Moreover, in thrombin-induced rat primary microglial cells, JWH133 reduced the pro-inflammatory cytokine levels and M1 phenotype by enhancing the acquisition of the M2 phenotype. Additionally, JWH133 facilitated synthesis of cyclic AMP (cAMP) and its downstream effectors, phosphorylated cAMP-dependent protein kinase (p-PKA) and exchange protein activated by cyclic-AMP 1 (Epac1). The promoting effects of JWH133 on M2 polarization were attenuated with a specific PKA inhibitor but not with an Epac inhibitor, indicating that the cAMP/PKA signaling pathway was involved in the JWH133 effects. This is the first study to propose that promotion of microglial M2 polarization through the cAMP/PKA pathway participates in the CB2R-mediated anti-inflammatory effects after GMH induction. The results will help to further understand the mechanisms that underlie neuroprotection by CB2R in GMH and promote clinical translational research for CB2R agonists.

Pharmacological Preventions of Brain Injury Following Experimental Germinal Matrix Hemorrhage: an Up-to-Date Review

Germinal matrix hemorrhage (GMH) is defined as the rupture of immature blood vessels in the subependymal zone of premature infants with significant mortality and morbidity. Considering the notable social and ecological stress brought by GMH-induced brain injury and sequelae, safe and efficient pharmacological preventions are badly needed. Currently, several appropriate animal models are available to mimic the clinical outcomes of GMH in human patients. In the long run, hemorrhagic strokes are the research target. Previously, we found that minocycline was efficient to alleviate GMH-induced brain edema and posthemorrhagic hydrocephalus (PHH) in rats, which may be closely related to the activation of cannabinoid receptor 2 (CB2R). However, how the two molecules correlate and the underlined molecular pathway remain unknown. To extensively understand current experimental GMH treatment, this literature review critically evaluates existing therapeutic strategies, potential treatments, and potentially involved molecular mechanisms. Each strategy has its own advantages and disadvantages. Some of the mechanisms are still controversial, requiring an increasing number of animal experiments before the therapeutic strategy would be widely accepted.

Cannabinoid receptor 2 attenuates microglial accumulation and brain injury following germinal matrix hemorrhage via ERK dephosphorylation in vivo and in vitro

Microglia accumulation plays detrimental roles in the pathology of germinal matrix hemorrhage (GMH) in the immature preterm brain. However, the underlying mechanisms remain poorly defined. Here, we investigated the effects of a cannabinoid receptor 2 (CB2R) agonist on microglia proliferation and the possible involvement of the mitogen-activated protein kinase (MAPK) family pathway in a collagenase-induced GMH rat model and in thrombin-induced rat microglia cells. We demonstrated that activation of CB2R played a key role in attenuating brain edema, neuronal degeneration, microglial accumulation and the phosphorylated extracellular signal-regulated kinase (p-ERK) protein level 24 h following GMH. In vitro, Western blot analysis and immunostaining indicated that ERK and P38 phosphorylation levels in microglia stimulated by thrombin were decreased after JWH-133 (CB2R selective agonist) treatment in a concentration-dependent manner. Microglia proliferation (EDU + microglia) and inflammatory and oxidative stress responses were attenuated by UO126 (ERK pathway inhibitor) 24 h after thrombin stimulation, an activity that was prevented by AM630 (CB2R selective antagonist). Overall, these findings suggest that activation of the endocannabinoid system might attenuate inflammation-induced secondary brain injury after GMH in rats by reducing microglia accumulation through a mechanism involving ERK dephosphorylation. Enhancing CB2R activation is a potential treatment to slow down the course of GMH in preterm newborns.

Preterm birth trend in Taiwan from 2001 to 2009

AIM

The aim of this study was to analyze the trends and risk factors of preterm birth from all the women who delivered during 2001-2009 in Taiwan.

MATERIAL AND METHODS

We analyzed the preterm birth rates, the proportions of obstetric antecedents and risk factors in the population of pregnant women and neonatal Apgar scores according to the National Medical Birth Register database from 2001 to 2009. Adjusted odds ratios (OR) with 95% confidence intervals for risk factors of preterm birth were assessed using multivariable logistic regression models. The obstetric antecedents of preterm birth for singletons were stratified by spontaneous preterm labor and indicated preterm delivery (labor induction or elective cesarean delivery).

RESULTS

The preterm birth rate was 8.56% with the majority (89.76%) delivered between 32 and 37 weeks of gestation. A 0.07% annual increase (P < 0.001) in preterm delivery was observed. The greatest risk factors were multiple pregnancies (OR > 20), followed by medical complications (OR > 2.8), congenital malformations (OR > 2), teen pregnancies (OR > 1), and advanced maternal age (OR > 1). Specifically, singleton preterm births comprised 57.3% spontaneous labor and 42.7% indicated delivery. There was a 0.5% annual increase (P < 0.001) in indicated delivery. Incidence of neonates with poor Apgar scores (<7) was significantly different between those with and without medical complications (P < 0.001).

CONCLUSIONS

The preterm birth rate increased significantly from 2001 to 2009 and multiple pregnancies were the most important contributing factor. Most of the singleton preterm births resulted from spontaneous labor, but the proportion of indicated deliveries increased.

Minocycline Attenuates Neonatal Germinal-Matrix-Hemorrhage-Induced Neuroinflammation and Brain Edema by Activating Cannabinoid Receptor 2

Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns leading to detrimental neurological sequelae. Minocycline has been reported to play a key role in neurological inflammatory diseases by controlling some mechanisms that involve cannabinoid receptor 2 (CB2R). The current study investigated whether minocycline reduces neuroinflammation and protects the brain from injury in a rat model of collagenase-induced GMH by regulating CB2R activity. To test this hypothesis, the effects of minocycline and a CB2R antagonist (AM630) were evaluated in male rat pups that were post-natal day 7 (P7) after GMH. We found that minocycline can lead to increased CB2R mRNA expression and protein expression in microglia. Minocycline significantly reduced GMH-induced brain edema, microglial activation, and lateral ventricular volume. Additionally, minocycline enhanced cortical thickness after injury. All of these neuroprotective effects of minocycline were prevented by AM630. A cannabinoid CB2 agonist (JWH133) was used to strengthen the hypothesis, which showed the identical neuroprotective effects of minocycline. Our study demonstrates, for the first time, that minocycline attenuates neuroinflammation and brain injury in a rat model of GMH, and activation of CBR2 was partially involved in these processes.

Impact of chorioamnionitis on short- and long-term outcomes in very low birth weight preterm infants: the Neonatal Research Network Japan

OBJECTIVE

To evaluate the short- and long-term outcomes among very low birth weight (VLBW) preterm infants after histologic chorioamnionitis (HCA).

METHODS

We performed a retrospective analysis of 5849 single infants (birth weight <1500 g) born at a gestational age between 22 + 0 and 33 + 6 weeks. Clinical data were obtained from the Neonatal Research Network Japan between 2003 and 2007. Multivariable logistic regression analyses were performed to assess the effect of HCA on short- and long-term outcome.

RESULTS

According to logistic regression analysis, HCA was associated with lower incidence of respiratory distress syndrome (odds ratio [OR] = 0.54; p < 0.001), increased chronic lung disease (OR = 1.68; p < 0.001) and sepsis (OR = 1.71; p < 0.001) and as a short-term outcomes. There was no significant association with intraventricular hemorrhage (OR = 1.11; p = 0.33), periventricular leukomalacia (OR = 1.07; p = .070) and death before discharge (OR = 0.97; p = 0.084). HCA was associated with increased home oxygen therapy (OR = 3.09; p < 0.001), but not with cerebral palsy (CP; OR = 0.91; p = 0.63), develop quotient < 70 (OR = 1.27; p = 0.17), visual impairment (OR = 1.08; p = 0.77), severe hearing impairment (OR = 1.28; p = 0.62) and death (OR = 0.98; p = 0.91) before three years of age.

CONCLUSIONS

In this retrospective population-based study in Japan, HCA was not a risk factor for death, neurodevelopmental impairment and CP in VLBW three-year-old preterm infants.

Changes in risk factors for preterm birth in Western Australia 1984-2006

OBJECTIVE

To characterise changing risk factors of preterm birth in Western Australia between 1984 and 2006.

DESIGN

Population-based study.

SETTING

Western Australia.

POPULATION

All non-Aboriginal women giving birth to live singleton infants between 1984 and 2006.

METHODS

Multinomial, multivariable regression models were used to assess antecedent profiles by preterm status and labour onset types (spontaneous, medically indicated, prelabour rupture of membranes [PROM]). Population attributable fraction (PAF) estimates characterized the contribution of individual antecedents as well as the overall contribution of two antecedent groups: pre-existing medical conditions (including previous obstetric history) and pregnancy complications.

MAIN OUTCOME MEASURE

Antecedent relationships with preterm birth, stratified by labour onset type.

RESULTS

Marked increases in maternal age and primiparous births were observed. A four-fold increase in the rates of pre-existing medical complications over time was observed. Rates of pregnancy complications remained stable. Multinomial regression showed differences in antecedent profiles across labour onset types. PAF estimates indicated that 50% of medically indicated preterm deliveries could be eliminated after removing six antecedents from the population; estimates for PROM and spontaneous preterm reduction were between 10 and 20%. Variables pertaining to previous and current obstetric complications (previous preterm birth, previous caesarean section, pre-eclampsia and antepartum haemorrhage) were the most influential predictors of preterm birth and adverse labour onset (PROM and medically indicated).

CONCLUSIONS

Preterm antecedent profiles have changed markedly over the 23 years studied. Some changes may be attributable to true change, others to advances in surveillance and detection. Still others may signify change in clinical practice.

Low Birth Weight due to Intrauterine Growth Restriction and/or Preterm Birth: Effects on Nephron Number and Long-Term Renal Health

Epidemiological studies have clearly demonstrated a strong association between low birth weight and long-term renal disease. A potential mediator of this long-term risk is a reduction in nephron endowment in the low birth weight infant at the beginning of life. Importantly, nephrons are only formed early in life; during normal gestation, nephrogenesis is complete by about 32–36 weeks, with no new nephrons formed after this time during the lifetime of the individual. Hence, given that a loss of a critical number of nephrons is the hallmark of renal disease, an increased severity and acceleration of renal disease is likely when the number of nephrons is already reduced prior to disease onset. Low birth weight can result from intrauterine growth restriction (IUGR) or preterm birth; a high proportion of babies born prematurely also exhibit IUGR. In this paper, we describe how IUGR and preterm birth adversely impact on nephrogenesis and how a subsequent reduced nephron endowment at the beginning of life may lead to long-term risk of renal disease, but not necessarily hypertension.

Rodent neonatal germinal matrix hemorrhage mimics the human brain injury, neurological consequences, and post-hemorrhagic hydrocephalus

Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns. GMH causes neurological sequelae such as cerebral palsy, post-hemorrhagic hydrocephalus, and mental retardation. Despite this, there is no standardized animal model of spontaneous GMH using newborn rats to depict the condition. We asked whether stereotactic injection of collagenase type VII (0.3 U) into the ganglionic eminence of neonatal rats would reproduce the acute brain injury, gliosis, hydrocephalus, periventricular leukomalacia, and attendant neurological consequences found in humans. To test this hypothesis, we used our neonatal rat model of collagenase-induced GMH in P7 pups, and found that the levels of free-radical adducts (nitrotyrosine and 4-hyroxynonenal), proliferation (mammalian target of rapamycin), inflammation (COX-2), blood components (hemoglobin and thrombin), and gliosis (vitronectin and GFAP) were higher in the forebrain of GMH pups, than in controls. Neurobehavioral testing showed that pups with GMH had developmental delay, and the juvenile animals had significant cognitive and motor disability, suggesting clinical relevance of the model. There was also evidence of white-matter reduction, ventricular dilation, and brain atrophy in the GMH animals. This study highlights an instructive animal model of the neurological consequences after germinal matrix hemorrhage, with evidence of brain injuries that can be used to evaluate strategies in the prevention and treatment of post-hemorrhagic complications.

Prevention of preterm birth

Preterm birth (delivery before 37 completed weeks of gestation) is common and rates are increasing. In the past, medical efforts focused on ameliorating the consequences of prematurity rather than preventing its occurrence. This approach resulted in improved neonatal outcomes, but it remains costly in terms of both the suffering of infants and their families and the economic burden on society. Increased understanding of the pathophysiology of preterm labor has altered the approach to this problem, with increased focus on preventive strategies. Primary prevention is a limited strategy which involves public education, smoking cessation, improved nutritional status and avoidance of late preterm births. Secondary prevention focuses on recurrent preterm birth which is the most recognisable risk factor. Widely accepted strategies include cervical cerclage, progesterone and dedicated clinics. However, more research is needed to explore the role of antibiotics and anti-inflammatory treatments in the prevention of this complex problem.

The use of fetal fibronectin testing in the management of a triplet pregnancy with a short cervix

Following in vitro fertilisation treatment, a 40-year-old woman was expecting trichorionic, triamniotic triplets. Her cervix shortened from 34 mm at 16(+5) weeks to 16 mm at 20(+5) weeks, a risk reported with 100% delivery before 28 weeks gestation. She was admitted to hospital and at 24(+1) weeks was given corticosteroids. From 21(+5) weeks her cervical length remained below 16 mm. However, weekly fetal fibronectin (fFN) tests were negative from 22(+5) weeks to delivery at 35(+5) weeks. This, along with an absence of symptoms, gave her doctors confidence to manage her as an outpatient from 28 weeks. At 33(+5) weeks she was diagnosed as having pre-eclampsia and three live births were delivered by prelabour caesarean section. Prior to delivery her cervical length was 10 mm and fFN test remained negative. There are no reports of outcome following a negative fFN with a short cervix in triplet pregnancies but fFN could be a useful tool, in conjunction with cervical length measurement, in the management of triplets.

Changes in the distribution of maternal age and parity and increasing trends in the low birth weight rate in Korea between 1995 and 2005

OBJECTIVES

This study measured the impact of shifts in maternal age and parity on the increase in the low birth weight (LBW) rate in Korea.

METHODS

We obtained raw data for all 6 397 945 live births registered at the Korea National Statistical Office between 1995 and 2005. We calculated the proportion of increment in the LBW rate due to changes in the distribution of maternal age and parity (AP-dis) and the proportion due to changes in the age- and parity-specific LBW rate (AP-spe).

RESULTS

The LBW rate increased from 3.02% in 1995 to 4.28% in 2005. The multiple birth rate increased from 1.32% to 2.19% during the same period. Of the 1.26% points increment in the LBW rate, 0.64% points occurred among singleton births and 0.62% points occurred among multiple births. Changes in the AP-dis accounted for 50% of the increase in the LBW rate among singleton births, but did not contribute to the increase in the LBW rate among multiple births. The remainder of the total increment in the LBW rate was explained by the increase in the AP-spe.

CONCLUSIONS

This study demonstrated that shifts in maternal age and parity among singleton births and increased multiple births were important contributors to the increment in the LBW rate. This study also revealed that the increase in the AP-spe was an equally important contributor as the shifts in maternal age and parity to the increment in the LBW rate among singleton births and was a major contributor among multiple births.

Neuroprotection in a rabbit model of intraventricular haemorrhage by cyclooxygenase-2, prostanoid receptor-1 or tumour necrosis factor-alpha inhibition

Intraventricular haemorrhage is a major complication of prematurity that results in neurological dysfunctions, including cerebral palsy and cognitive deficits. No therapeutic options are currently available to limit the catastrophic brain damage initiated by the development of intraventricular haemorrhage. As intraventricular haemorrhage leads to an inflammatory response, we asked whether cyclooxygenase-2, its derivative prostaglandin E2, prostanoid receptors and pro-inflammatory cytokines were elevated in intraventricular haemorrhage; whether their suppression would confer neuroprotection; and determined how cyclooxygenase-2 and cytokines were mechanistically-linked. To this end, we used our rabbit model of intraventricular haemorrhage where premature pups, delivered by Caesarian section, were treated with intraperitoneal glycerol at 2 h of age to induce haemorrhage. Intraventricular haemorrhage was diagnosed by head ultrasound at 6 h of age. The pups with intraventricular haemorrhage were treated with inhibitors of cyclooxygenase-2, prostanoid receptor-1 or tumour necrosis factor-α; and cell-infiltration, cell-death and gliosis were compared between treated-pups and vehicle-treated controls during the first 3 days of life. Neurobehavioural performance, myelination and gliosis were assessed in pups treated with cyclooxygenase-2 inhibitor compared to controls at Day 14. We found that both protein and messenger RNA expression of cyclooxygenase-2, prostaglandin E2, prostanoid receptor-1, tumour necrosis factor-α and interleukin-1β were consistently higher in the forebrain of pups with intraventricular haemorrhage relative to pups without intraventricular haemorrhage. However, cyclooxygenase-1 and prostanoid receptor 2-4 levels were comparable in pups with and without intraventricular haemorrhage. Cyclooxygenase-2, prostanoid receptor-1 or tumour necrosis factor-α inhibition reduced inflammatory cell infiltration, apoptosis, neuronal degeneration and gliosis around the ventricles of pups with intraventricular haemorrhage. Importantly, cyclooxygenase-2 inhibition alleviated neurological impairment, improved myelination and reduced gliosis at 2 weeks of age. Cyclooxygenase-2 or prostanoid receptor-1 inhibition reduced tumour necrosis factor-α level, but not interleukin-1β. Conversely, tumour necrosis factor-α antagonism did not affect cyclooxygenase-2 expression. Hence, prostanoid receptor-1 and tumour necrosis factor-α are downstream to cyclooxygenase-2 in the inflammatory cascade induced by intraventricular haemorrhage, and cyclooxygenase-2-inhibition or suppression of downstream molecules--prostanoid receptor-1 or tumour necrosis factor-α--might be a viable neuroprotective strategy for minimizing brain damage in premature infants with intraventricular haemorrhage.

The APPLe study: a randomized, community-based, placebo-controlled trial of azithromycin for the prevention of preterm birth, with meta-analysis

BACKGROUND

Premature birth is the major cause of perinatal mortality and morbidity in both high- and low-income countries. The causes of preterm labour are multiple but infection is important. We have previously described an unusually high incidence of preterm birth (20%) in an ultrasound-dated, rural, pregnant population in Southern Malawi with high burdens of infective morbidity. We have now studied the impact of routine prophylaxis with azithromycin as directly observed, single-dose therapy at two gestational windows to try to decrease the incidence of preterm birth.

METHODS AND FINDINGS

We randomized 2,297 pregnant women attending three rural and one peri-urban health centres in Southern Malawi to a placebo-controlled trial of oral azithromycin (1 g) given at 16-24 and 28-32 wk gestation. Gestational age was determined by ultrasound before 24 wk. Women and their infants were followed up until 6 wk post delivery. The primary outcome was incidence of preterm delivery, defined as <37 wk. Secondary outcomes were mean gestational age at delivery, perinatal mortality, birthweight, maternal malaria, and anaemia. Analysis was by intention to treat. There were no significant differences in outcome between the azithromycin group (n = 1,096) and the placebo group (n = 1,087) in respect of preterm birth (16.8% versus 17.4%), odds ratio (OR) 0.96, 95% confidence interval (0.76-1.21); mean gestational age at delivery (38.5 versus 38.4 weeks), mean difference 0.16 (-0.08 to 0.40); mean birthweight (3.03 versus 2.99 kg), mean difference 0.04 (-0.005 to 0.08); perinatal deaths (4.3% versus 5.0%), OR 0.85 (0.53-1.38); or maternal malarial parasitaemia (11.5% versus 10.1%), OR 1.11 (0.84-1.49) and anaemia (44.1% versus 41.3%) at 28-32 weeks, OR 1.07 (0.88-1.30). Meta-analysis of the primary outcome results with seven other studies of routine antibiotic prophylaxis in pregnancy (>6,200 pregnancies) shows no effect on preterm birth (relative risk 1.02, 95% confidence interval 0.86-1.22).

CONCLUSIONS

This study provides no support for the use of antibiotics as routine prophylaxis to prevent preterm birth in high risk populations; prevention of preterm birth requires alternative strategies.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN84023116

Image analysis for retinopathy of prematurity diagnosis

PURPOSE

To review findings from the authors' published studies involving telemedicine and image analysis for retinopathy of prematurity (ROP) diagnosis.

METHODS

Twenty-two ROP experts interpreted a set of 34 wide-angle retinal images for presence of plus disease. For each image, a reference standard diagnosis was defined from expert consensus. A computer-based system was used to measure individual and linear combinations of image parameters for arteries and veins: integrated curvature (IC), diameter, and tortuosity index (TI). Sensitivity, specificity, and receiver operating characteristic areas under the curve (AUC) for plus disease diagnosis were determined for each expert. Sensitivity and specificity curves were calculated for the computer-based system by varying the diagnostic cutoffs for arterial IC and venous diameter. Individual vessels from the original 34 images were identified with particular diagnostic cutoffs, and combined into composite wide-angle images using graphics editing software.

RESULTS

For plus disease diagnosis, expert sensitivity ranged from 0.308-1.000, specificity from 0.571-1.000, and AUC from 0.784 to 1.000. Among computer system parameters, one linear combination had AUC 0.967, which was greater than that of 18 of 22 (81.8%) experts. Composite computer-generated images were produced using the arterial IC and venous diameter values associated with 75% under-diagnosis of plus disease (ie, 25% sensitivity cutoff), 50% under-diagnosis of plus disease (ie, 50% sensitivity cutoff), and 25% under-diagnosis of plus disease (ie, 75% sensitivity cutoff).

CONCLUSIONS

Computer-based image analysis has the potential to diagnose severe ROP with comparable or better accuracy than experts, and could provide added value to telemedicine systems. Future quantitative definitions of plus disease might improve diagnostic objectivity.

Telemedicine for retinopathy of prematurity diagnosis: evaluation and challenges

Retinopathy of prematurity (ROP) is a vasoproliferative disorder affecting low birth weight infants. Although timely diagnosis and treatment can significantly reduce the risk of severe complications, ROP remains a leading cause of childhood blindness worldwide. Limitations of current disease management strategies include extensive travel and logistical coordination requirements for ophthalmologists and neonatologists, decreasing availability of adequately trained ophthalmologists at the point of care, variability in how retinal findings are diagnosed and documented, and a growing need for ROP care worldwide. Store-and-forward telemedicine is an emerging technology by which medical data are captured for subsequent interpretation by a remote expert. This has potential to improve accessibility, quality, and cost of ROP management. In this article, we summarize the current evaluation data on applications of telemedicine for ROP, particularly involving the diagnostic accuracy and reliability of remote image interpretation by experts. We also address challenges such as the cost-effectiveness of telemedicine, and highlight potential barriers to implementation of these systems. Understanding these principles is essential to determine future directions in research and development of telemedicine systems for ROP, as well as for other ophthalmic diseases.

Consequences of intraventricular hemorrhage in a rabbit pup model

BACKGROUND AND PURPOSE

Intraventricular hemorrhage (IVH) is a common complication of prematurity that results in neurological sequelae, including cerebral palsy, posthemorrhagic hydrocephalus, and cognitive deficits. Despite this, there is no standardized animal model exhibiting neurological consequences of IVH in prematurely delivered animals. We asked whether induction of moderate-to-severe IVH in premature rabbit pups would produce long-term sequelae of cerebral palsy, posthemorrhagic hydrocephalus, reduced myelination, and gliosis.

METHODS

The premature rabbit pups, delivered by cesarean section, were treated with intraperitoneal glycerol at 2 hours postnatal age to induce IVH. The development of IVH was diagnosed by head ultrasound at 24 hours of age. Neurobehavioral, histological, and ultrastructural evaluation and diffusion tensor imaging studies were performed at 2 weeks of age.

RESULTS

Although 25% of pups with IVH (IVH pups) developed motor impairment with hypertonia and 42% developed posthemorrhagic ventriculomegaly, pups without IVH (non-IVH) were unremarkable. Immunolabeling revealed reduced myelination in the white matter of IVH pups compared with saline- and glycerol-treated non-IVH controls. Reduced myelination was confirmed by Western blot analysis. There was evidence of gliosis in IVH pups. Ultrastructural studies in IVH pups showed that myelinated and unmyelinated fibers were relatively preserved except for focal axonal injury. Diffusion tensor imaging showed reduction in fractional anisotropy and white matter volume confirming white matter injury in IVH pups.

CONCLUSION

The rabbit pups with IVH displayed posthemorrhagic ventriculomegaly, gliosis, reduced myelination, and motor deficits, like humans. The study highlights an instructive animal model of the neurological consequences of IVH, which can be used to evaluate strategies in the prevention and treatment of posthemorrhagic complications.

Speed of telemedicine vs ophthalmoscopy for retinopathy of prematurity diagnosis

PURPOSE

To compare the speed of retinopathy of prematurity (ROP) diagnosis using standard indirect ophthalmoscopy with that of telemedicine.

DESIGN

Prospective, comparative study.

METHODS

Three study examiners (2 pediatric retinal specialists [R.V.P.C., T.C.L.] and 1 pediatric ophthalmologist [M.F.C.]) conducted ROP diagnosis via standard indirect ophthalmoscopy and telemedicine. Each examiner performed: 1) standard ophthalmoscopy on 72 to 150 consecutive infants at his respective institution and 2) telemedical diagnosis on 125 consecutive deidentified retinal image sets from infants from an at-risk population. Time for ophthalmoscopic diagnosis was measured in 2 ways: 1) time spent by the examiner at the infant's bedside and 2) mean total time commitment per infant. Time for telemedicine diagnosis was recorded by computer time stamps in the web-based system. For each examiner, nonparametric statistical analysis (Mann-Whitney U test) was used to compare the distribution of times for examination by ophthalmoscopy vs telemedicine.

RESULTS

Mean (+/- standard deviation [SD]) times for ophthalmoscopic diagnosis ranged from 4.17 (+/- 1.34) minutes to 6.63 (+/- 2.28) minutes per infant. Mean (+/- SD) times for telemedicine diagnosis ranged from 1.02 (+/- 0.27) minutes to 1.75 (+/- 0.80) minutes per infant. Telemedicine was significantly faster than ophthalmoscopy (P < .0001). The total time commitment by ophthalmologists performing bedside ophthalmoscopy for ROP diagnosis, including travel and communication with families and hospital staff, was 10.08 (+/- 2.53) minutes to 14.42 (+/- 2.64) minutes per infant.

CONCLUSIONS

The ophthalmologist time requirement for telemedical ROP diagnosis is significantly less than that for ophthalmoscopic diagnosis. Additional time requirements associated with bedside ROP diagnosis increased this disparity. Telemedicine has potential to alleviate the time commitment for ophthalmologists who manage ROP.

A randomized controlled trial of cervical scanning vs history to determine cerclage in women at high risk of preterm birth (CIRCLE trial)

OBJECTIVE

We sought to compare history-indicated placement of cervical cerclage based on history- vs ultrasound-indicated placement in women at risk of preterm birth.

STUDY DESIGN

We conducted a randomized controlled trial of history-indicated cervical cerclage suture based on history (clinician preference) vs ultrasound (< 20 mm cervical length) indicated in women at increased risk.

RESULTS

The incidence of the primary outcome, preterm delivery between 24(+0) and 33(+6) weeks, was similar: 19/125 (15%) in the history-indicated group vs 18/122 (15%) in the ultrasound-indicated group (relative risk [RR], 0.97; 95% confidence interval [CI], 0.54-1.76). Those women randomized to the ultrasound-indicated arm were significantly more likely to receive a cerclage (32% vs 19%; RR, 1.66; 95% CI, 1.07-2.47) and progesterone (39% vs 25%; RR, 1.55; 95% CI, 1.06-2.25).

CONCLUSION

Screening women at high risk with cervical ultrasound to determine cerclage placement results in more intervention but similar outcome compared with history-indicated placement.

A critical assessment of adverse pregnancy outcome and periodontal disease

BACKGROUND

Pre-term birth is a major cause of infant mortality and morbidity that has considerable societal, medical, and economic costs. The rate of pre-term birth appears to be increasing world-wide and efforts to prevent or reduce its prevalence have been largely unsuccessful.

AIM

To review the literature for studies investigating periodontal disease as a possible risk factor for pre-term birth and adverse pregnancy outcomes.

MAIN FINDINGS AND CONCLUSION

Variability among studies in definitions of periodontal disease and adverse pregnancy outcomes as well as widespread inadequate control for confounding factors and possible effect modification make it difficult to base meaningful conclusions on published data. However, while there are indications of an association between periodontal disease and increased risk of adverse pregnancy outcome in some populations, there is no conclusive evidence that treating periodontal disease improves birth outcome. Based on a critical qualitative review, available evidence from clinical trials indicates that, although non-surgical mechanical periodontal treatment in the second trimester of pregnancy is safe and effective in reducing signs of maternal periodontal disease, it does not reduce the rate of pre-term birth. Clinical trials currently underway will further clarify the potential role of periodontal therapy in preventing adverse birth outcomes. Regardless of the outcomes of these trials, it is recommended that large, prospective cohort studies be conducted to assess risk for adverse pregnancy outcome in populations with periodontal disease. It is critical that periodontal exposure and adverse birth outcomes be clearly defined and the many potential confounding factors and possible effect modifiers for adverse pregnancy outcome be controlled in these studies. If periodontal disease is associated with higher risk of adverse pregnancy outcome in these specific populations, large multicenter randomized-controlled trials will be needed to determine if prevention or treatment of periodontal disease, perhaps combined with other interventions, has an effect on adverse pregnancy outcome in these women.

Occupational factors and risk of preterm birth in nurses

OBJECTIVE

We evaluated first-trimester exposures and the risk of preterm birth in the most recent pregnancy of participants of the Nurses' Health Study II.

STUDY DESIGN

Log binomial regression was used to estimate the relative risk (RR) for preterm birth in relation to occupational risk factors, such as work schedule, physical factors, and exposures to chemicals and x-rays, adjusted for age and parity.

RESULTS

Part-time work (<or= 20 hours a week) was associated with a lower risk of preterm birth [RR, 0.7; 95% confidence interval [CI], 0.6-0.9]. Working nights was associated only with early preterm birth (< 32 weeks of gestation) (RR, 3.0; 95% CI, 1.4-6.2). Although based on only 11 exposed preterm cases, self-reported exposure to sterilizing agents was associated with an increased risk (RR, 1.9; 95% CI, 1.1-3.4).

CONCLUSION

These data suggest that night work may be related to early but not late preterm birth, whereas physically demanding work did not strongly predict risk.

Characterization of acute brain injuries and neurobehavioral profiles in a rabbit model of germinal matrix hemorrhage

BACKGROUND AND PURPOSE

Germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) is the most common neurological problem of premature infants and has enormous financial and social impact. Despite this, there is no standardized animal model of IVH depicting acute brain injuries.

METHODS

We delivered rabbit-pups prematurely at 29-day gestation by C-section, administered intraperitoneal glycerol to the pups at 3-hour postnatal age to induce IVH, and evaluated the brain for evidence of injuries.

RESULTS

About 80% of glycerol-treated pups developed gross IVH. We found greater neutrophil and microglia infiltration around the ventricles (periventricular zone) in pups with IVH than in controls. We noted more apoptosis and neuronal degeneration in the periventricular zone than in the neocortex in pups with IVH, but not in controls. There was evidence of axonal damage revealed by beta-amyloid precursor protein and neurofilament immunolabeling. Neurobehavioral testing showed that pups with IVH were more wobbly with lesser capability to walk on inclination than pups without IVH. There was no evidence of acute systemic toxicity in the glycerol-treated pups. An evaluation of autopsy materials from premature infants revealed similar evidence of apoptosis and cellular infiltration in the periventricular zone in cases with IVH, but not in cases without IVH-suggesting clinical relevance of the model.

CONCLUSIONS

The study provides an instructive animal model of IVH with evidence of acute brain injuries that can be used to evaluate strategies in prevention of IVH and acute posthemorrhagic complications.

Paucity of pericytes in germinal matrix vasculature of premature infants

Germinal matrix (GM) is a richly vascularized collection of neuronal-glial precursor cells in the developing brain, which is selectively vulnerable to hemorrhage in premature infants. It has rapid angiogenesis associated with high levels of vascular endothelial growth factor (VEGF). Because pericytes provide structural stability to blood vessels, we asked whether pericytes were fewer in the GM than in the subjacent white matter and neocortex and, if so, whether angiogenic inhibition could increase the pericyte density in the GM. We found pericyte coverage and density less in the GM vasculature than in the cortex or white matter in human fetuses, premature infants, and premature rabbit pups. Notably, although VEGF suppression significantly enhanced pericyte coverage in the GM, it remained less than in other brain regions. Therefore, to further elucidate the basis of fewer pericytes in the GM vasculature, we examined expression of ligand-receptor systems responsible for pericyte recruitment. Transforming growth factor-beta1 (TGF-beta1) protein expression was lower, whereas sphingosine-1-phosphate1 (S1P1) and N-cadherin levels were higher in the GM than in the cortex or white matter. Low TGF-beta1 may be involved in promoting endothelial proliferation, whereas elevated S1P1 with N-cadherin may assist vascular maturation. Hence, a paucity of pericytes in the GM vasculature may contribute to its propensity to hemorrhage, and a lower expression of TGF-beta1 could be a basis of reduced pericyte density in its vasculature.

Outcome following preterm birth

Preterm birth currently occurs in approximately 12% of pregnancies and appears to be increasing despite improvements in obstetric care. Improvements in neonatal care have led to increased survival, particularly at extreme prematurity, but survival may be associated with significant morbidity. This may be acute, reflecting the difficulties in supporting an individual in a hostile extrauterine environment to which they should not be exposed, or chronic, reflecting disturbances to fragile, immature body systems. Brain, lungs, intestines and eyes are particularly vulnerable and damage may be severe. For some infants the consequences of this damage may be permanent disability and impairment. Despite this, the limited information currently available suggests that adult outcomes may be comparable with those for infants born at term.

A meta-analysis on the influence of inflammatory bowel disease on pregnancy

BACKGROUND

Inflammatory bowel disease (IBD) has a typical onset during the peak reproductive years. Evidence of the risk of adverse pregnancy outcomes in IBD is important for the management of pregnancy to assist in its management.

AIM

To provide a clear assessment of risk of adverse outcomes during pregnancy in women with IBD.

DESIGN

The Medline literature was searched to identify studies reporting outcomes of pregnancy in patients with IBD. Random-effect meta-analysis was used to compare outcomes between women with IBD and normal controls.

PATIENTS AND SETTING

A total of 3907 patients with IBD (Crohn's disease 1952 (63%), ulcerative colitis 1113 (36%)) and 320 531 controls were reported in 12 studies that satisfied the inclusion criteria.

RESULTS

For women with IBD, there was a 1.87-fold increase in incidence of prematurity (<37 weeks gestation; 95% CI 1.52 to 2.31; p<0.001) compared with controls. The incidence of low birth weight (<2500 g) was over twice that of normal controls (95% CI 1.38 to 3.19; p<0.001). Women with IBD were 1.5 times more likely to undergo caesarean section (95% CI 1.26 to 1.79; p<0.001), and the risk of congenital abnormalities was found to be 2.37-fold increased (95% CI 1.47 to 3.82; p<0.001).

CONCLUSION

The study has shown a higher incidence of adverse pregnancy outcomes in patients with IBD. Further studies are required to clarify which women are at higher risk, as this was not determined in the present study. This has an effect on the management of patients with IBD during pregnancy, who should be treated as a potentially high-risk group.

Spontaneous preterm birth of liveborn infants in women at low risk in Australia over 10 years: a population-based study

OBJECTIVES

To describe a 10-year trend in preterm birth.

DESIGN

Population-based study.

SETTING

Australia.

POPULATION

All women who gave birth during 1994-03.

METHODS

The proportion of spontaneous preterm births (greater than or equal to 22 weeks of gestation and less than 37 completed weeks of gestation) was calculated by dividing the number of women who had a live spontaneous preterm birth (excluding elective caesarean section and induction of labour) by the total number of women who had a live birth after spontaneous onset of labour (excluding elective caesarean section and induction of labour). This method was repeated for the selected population of women at low risk.

MAIN OUTCOME MEASURE

Preterm birth rates among the overall population of women; preterm birth among all women with a spontaneous onset of labour; and preterm birth in a selected population of women who were either primiparous or multiparous, non-Indigenous; aged 20-40 years and who gave birth to a live singleton baby after the spontaneous onset of labour.

RESULTS

Over the 10-year study period, the proportion of all women having a live preterm birth in Australia increased by 12.1% (from 5.9% in 1994 to 6.6% in 2003). Among women with a spontaneous onset of labour, there was an increase of 18.3% (from 5.7 to 6.7%). Among the selected population of low-risk women after the spontaneous onset of labour, the rate increased by 10.7% (from 5.6 to 6.2%) among first time mothers and by 19.2% (4.4-5.2%) among selected multiparous women.

CONCLUSIONS

Over the 10-year period of 1994-03, the rate of spontaneous preterm birth among low-risk women having a live singleton birth has risen in Australia.

Cervical cerclage in the prevention of preterm birth

Cervical cerclage has been used in the management of cervical insufficiency for several decades, yet the indications are uncertain and benefits marginal. It remains a controversial intervention. The diagnosis of cervical insufficiency is traditionally based on a history of recurrent second trimester miscarriages, or very preterm delivery whereby the cervix is unable to retain the pregnancy until term. Cervical cerclage has been the subject of many observational and randomised controlled trials. This article reviews the literature regarding the effectiveness of elective or emergency transvaginal cerclage and transabdominal cerclage.

PREMATURE CERVICAL CHANGE AND THE USE OF CERVICAL CERCLAGE

Preterm birth and its subsequent consequences continue to be a major challenge worldwide. In the United States in 2004, 12.5% of infants were born preterm, making the annual societal economic burden associated with preterm birth in excess of $26.2 billion (and this is a modest estimate). Spontaneous preterm birth accounts for about 75% of all preterm births; however, at earlier gestations iatrogenic preterm birth accounts for a greater proportion of all preterm births; at 27–28 weeks 50% are iatrogenic. The proportion of babies transferred to the neonatal unit is more than 90% for those born before 33 completed weeks of gestation compared with 31% at 36 weeks; delivery between 33 completed weeks and 36 completed weeks has a relatively low morbidity and mortality. Nonetheless, 1 in 3 children born preterm but beyond 32 weeks have educational and behavioural problems at the age of 7, with 1 in 4 children born between 32 and 35 weeks requiring support from non-teaching assistants at school. Although more than 40% of babies at 35 completed weeks show signs of maturity, some still need ventilation at 38 completed weeks. Almost one-fifth of all infants born at less than 32 weeks gestation do not survive the first year of life.

Preterm Delivery After Surgical Treatment for Cervical Intraepithelial Neoplasia

OBJECTIVE

To study whether a treatment of cervical intraepithelial neoplasia (CIN) is associated with an adverse outcome in the subsequent pregnancies.

METHODS

This study is a register-based retrospective cohort study from Finland. National data of 25,827 women having a surgical treatment of the cervix for CIN in 1986-2003 and their 8,210 subsequent singleton births in 1987-2004 were studied. Main outcome measures were preterm birth rate, low birth weight rate, and perinatal mortality rate.

RESULTS

The risk of any preterm delivery (less than 37 weeks of gestation), especially the risk of very preterm delivery (28-31 weeks of gestation), and extremely preterm delivery (less than 28 weeks of gestation) was increased after cervical conization (relative risk [RR] 1.99, 95% confidence interval [CI] 1.81-2.20; RR 2.86, 95% CI 2.22-3.70; and RR 2.10, 95% CI 1.47-2.99, respectively). After cervical ablation, the risk of preterm delivery was also increased. The risk of low birth weight and perinatal death was increased after conization (RR 2.06, 95% CI 1.83-2.31 and RR 1.74, 95% CI 1.30-2.32, respectively). Adjusting for maternal age, parity, and maternal smoking did not affect our results.

CONCLUSION

Any treatment for CIN, including loop electrosurgical excision procedure, increases the risk of preterm delivery. It is important to emphasize this when treating young women with CIN.

LEVEL OF EVIDENCE

II.

Preterm labour: update on prediction and prevention strategies

PURPOSE OF REVIEW

The incidence of preterm birth is increasing and continues to be a significant cause of neonatal mortality and morbidity. Techniques now exist that can accurately predict early birth. Prevention can therefore be targeted, although effective measures that improve outcome are yet to be established.

RECENT FINDINGS

Obtaining an accurate history is the first step in identifying high-risk women. Clinicians then rely on other predictors such as fetal fibronectin, cervical length assessment and biochemical markers. Research should focus on the combination of noninvasive markers targeted at high-risk women as a screening tool, determining not only appropriate diagnostic levels for positive tests, but also sufficiently large studies should be performed to determine the predictive values of these tests. Interventions to prevent delivery and improve neonatal outcome remain unsatisfactory, mainly comprising tocolysis, cerclage, progesterone and, in some cases, antibiotics. Women who would most benefit from these interventions are difficult to identify and an appreciation of the pathophysiology in an individual woman, such as the relevance of the inflammatory status of the endocervix, may be important in tailoring intervention.

SUMMARY

An improved understanding of the mechanisms underlying the pathological process in preterm birth will allow screening and interventions to be appropriately targeted.