Association between increased antenatal vaginal pH and preterm birth rate: a systematic review.

Background Worldwide, 14.9 million infants (11%) are born preterm each year. Up to 40% of preterm births (PTBs) are associated with genital tract infections. The vaginal pH can reflect changes in the vaginal milieu and, if elevated, indicates an abnormal flora or infection. Objective The aim of the study was to investigate whether an increased antenatal vaginal pH >4.5 in pre-labour pregnant women is associated with an increased PTB rate <37 completed weeks gestation. Search strategy Key databases included SCOPUS, EMBASE, MEDLINE, PsycInfo and the Cochrane Central Register of Controlled Trials, complemented by hand search, up to January 2017. Selection criteria Primary research reporting vaginal pH assessment in pre-labour pregnant women and PTB rate. Data collection and analysis Data extraction and appraisal were carried out in a pre-defined standardised manner, applying the Newcastle-Ottawa scale (NOS) and Cochrane risk of bias tool. Analysis included calculation of risk difference (RD) and narrative synthesis. It was decided to abstain from pooling of the studies due to missing information in important moderators. Main results Of 986 identified records, 30 were included in the systematic review. The risk of bias was considered mostly high (40%) or moderate (37%). Fifteen studies permitted a calculation of RD. Of these, 14 (93%) indicated a positive association between increased antenatal vaginal pH and PTB (RD range: 0.02-0.75). Conclusion An increased antenatal vaginal pH >4.5 may be associated with a higher risk for PTB. It is recommended to conduct a randomised controlled trial (RCT) to investigate the effectiveness of antenatal pH screening to prevent PTB. Tweetable abstract Pregnant women with an increased vaginal pH >4.5 may be at higher risk to experience preterm birth.

Exploring concepts and definitions of plateaus during normal labor and birth: a scoping review protocol.

OBJECTIVE: In this scoping review, contemporary concepts and definitions of phenomena during normal labor and birth, wherein the process appears to plateau (slow, stall, or pause) but remains within physiological limits, will be mapped. INTRODUCTION: During labor and birth, it is frequently perceived as pathological if contractions, cervical dilation, or fetal descent plateau. However, there is evidence to suggest that some plateaus during labor may be physiological, and a variety of concepts and terms refer to this phenomenon. Where a physiological plateau is perceived as pathological arrest, this may contribute to undue interventions, such as augmentation of labor. Therefore, it is important to advance understanding of physiological labor patterns, including potentially physiological labor plateaus. INCLUSION CRITERIA: Publications mentioning any plateaus of the processes of normal human labor and birth will be considered. This may also include phenomena where labor is perceived to "reverse," for example, a closing cervix or a rise of the presenting fetal part. Publications where plateaus are defined as pathological will be excluded. METHODS: All types of evidence, published and unpublished, will be considered. The search strategy will be applied to the databases MEDLINE, Embase, MIDIRS, Emcare, CINAHL, and Scopus, and will be limited to the past 30 years. Gray literature will be searched via Open Grey, reference list screening, and contacting authors. Data extraction will comprise information on concept boundaries, terminology, precedents, consequences, concept origin, and types of evidence that report this phenomenon. Results will be presented in tabular, diagrammatical, and narrative manner.