Background:The induction of labor (IOL) is a common obstetric intervention, steadily increasing (one out four pregnancies) in the last years. This procedure should be considered only when there is a medical indication, and when the benefits outweigh the maternal and/or fetal risks of waiting for spontaneous onset of labor. Therefore, this study aims to compare the efficacy of the IOL in terms of induction to delivery time, mode of delivery, and neonatal well-being among different evidence-based and non-evidence-based indications. Methods: This prospective study was conducted at the University Hospital of Modena, between January and December 2020. We included singleton pregnant women undergoing IOL, at the term. Intrauterine deaths, small for gestational age fetuses <5th centile as well women with hypertensive disorders were excluded. Women have been subdivided into 3 groups based on the indication to IOL: premature rupture of membranes (PROM), post-date pregnancy (>41 weeks + 3 days), and non-evidence-based indications (NEBI). The primary outcome is the time occurring between IOL and delivery (TIME), analyzing separately by parity. Moreover, mode of delivery and neonatal wellbeing were evaluated. Results: A total of 585 women underwent IOL in the study period. Overall, the median TIME between IOL and delivery was 19 hours, and the mean cesarean section CS rate was 15.5% (91/585). Pregnancies induced for postdate and non-evidencebased indications registered respectively a significantly higher mean time (p < 0.001), compared with women induced for PROM. This occurred both in nulliparous and multiparous women. Moreover, at multivariate analysis, the IOL TIME ≥24 hours was significantly influenced by Bishop score (p = 0.000) and NEBI (p = 0.02) in nulliparous and by gestational age (p = 0.000) and NEBI (p = 0.02) in multiparous. Moreover, CS rate was significantly influenced by Bishop score (p = 0.003) in nulliparous and by gestational age (p = 0.01) in multiparous. Finally, neonatal intensive care unit (NICU) admission resulted significantly influenced only by gestational age (p = 0.002) in multiparous. Conclusions: Our study confirms that IOL in non-evidence-based indications, leads to an increase in induction to delivery time comparing with women induced for PROM, both in nulliparous and multiparous women, thus it should be justified and carefully evaluated. Further randomized controlled trials (RCT) conducted in European/Italian settings are needed to determine the perinatal outcomes of IOL in non-evidence-based indications.Keywords: induction of labor; non-evidence-based indication; PROM; post-term pregnancy; ARRIVE trial; parity; cesarean section; the time between induction and delivery; NICU admission

Objectives: to evaluate the possible relationship between cultural specimens and preterm birth in women admitted for threatened preterm labour. Preterm birth is the leading cause of neonatal mortality and antenatal hospitalization: several risk factors including intrauterine infections have been identified but its real causes remain poorly understood. Design: retrospective, multicentre, cohort study including 250 women admitted for threatened preterm labour. Methods, Participants/Materials, Setting: all women admitted for threatened Preterm Labour, i.e. presenting with cervical changes and uterine activity before 37 weeks at the Obstetrics Unit of the hospitals of Modena, Monza, Carate and Vimercate were included in the study. We excluded twin pregnancies and cases with preterm premature rupture of membranes at admission. Data about maternal history, pregnancy complications, cervical length, vaginal swabs and urine culture at admission and gestational age at delivery were collected from clinical records in order to compare the incidence of preterm birth according to some known risk factors, cervical length and microbiological test at admission. Results: 250 women were included in the study; preterm birth at less than 37 weeks occurred in 44.4% women admitted for threatened preterm labour. The incidence of preterm birth was not different between those with a positive or a negative vaginal swab (45.7% vs. 39%, p=0.38), or positive vs. negative urine culture (31.8% vs. 42.1%, p=0.23) at admission. A shorter cervical length at admission was found in women with subsequent preterm birth (17± vs 19.5± mm, p=0.03). Cervical length <15 mm (OR 1.82, CI95% 1.03-3.23, p=0.039) predicted the risk of PTB. Further, only the history of a previous preterm birth (p=0.02) and a previous uterine curettage (p=0.045) were associated with preterm birth. Limitations: the observational and retrospective nature of the study and its small sample size are important limitations of the study. Moreover, women were not systematically or randomly assigned to the screening for vaginal or urinary infections. Conclusions: there is no evidence that the search for vaginal or urinary infections in women admitted for threatened preterm labour is helpful to identify those at increased risk of preterm birth. Although several studies have explored the role of screening for bacterial vaginosis in asymptomatic women and some studies evaluated vaginal or urinary infections in women with PTB, none of them focused on the possible role of microbiological specimens as a predictive tool in women admitted for threatened PTL. No association was found in our study but prospective randomized controlled trials are required to confirm the results of this observation.