Prevalence of Prolonged Latent Phase and Labor Outcomes: Review of Birth Records in a Swedish Population

Abstract

Introduction:The prevalence of a prolonged latent phase of labor has been described as ranging from 5% to 6.5% in previous research. The aim of this study was to describe the prevalence of the prolonged latent phase of 18 hours or more, based on women's report, in women intending vaginal birth and who had spontaneous onset of labor. An additional aim was to compare the incidence of obstetric interventions, and the labor and neonatal outcomes in women with and without a prolonged latent phase. Methods:A descriptive and comparative study was performed in a mid-sized hospital in western Sweden. The sample consisted of 1343 birth records of women who intended vaginal births and who had spontaneous onset of labor at 37 or more weeks' gestation during a one-year period (2013)(2014). Background characteristics, obstetric interventions, and labor and neonatal outcomes were compared between women with latent phases lasting less than 18 hours and 18 hours or more, based on women's self-report. Odds ratios with 95% confidence intervals were calculated for the different exposure variables.Results: A prolonged latent phase lasting 18 hours or more occurred in 23% of all births analyzed (n = 1343). A prolonged latent phase was more common among nulliparous women (29.2%) but also common for multiparous women (17%). Nulliparous and multiparous women who experienced a prolonged latent phase were more often exposed to amniotomy during latent phase. For nulliparous women, the adjusted odds ratio (aOR) was 11.57 (95% confidence interval [CI], 5.25-25.51) and for multiparous women the aOR was 18.73 (95% CI, 9.06-38.69). Similarly, amniotomy during active phase was more common for both nulliparous and multiparous women who experienced a prolonged latent phase (aOR, 4.05; 95% CI, 2.53-6.47 and aOR, 3.93; 95% CI, 2.43-6.37, respectively). Women with latent phases of 18 hours or more, more often experienced augmentation of labor during all phases, especially during latent phase. For nulliparous women, the aOR was 10.13 (95% CI, 2.82-36.39) and for multiparous women, aOR was11.9 (95% CI, 3.69-38.71). A prolonged latent phase was associated with more instrumental vaginal births for multiparas (aOR, 2.58; 95% CI, 1.27-5.26) and emergency cesarean regardless of parity (nulliparous women: aOR, 3.21; 95% CI, 1.08-9.50 and multiparous women: aOR, 3.93; 95% CI, 1.67-9.26).Discussion: Based on women's self-report, the prevalence of a prolonged latent phase in women at term who planned a vaginal birth and had spontaneous onset of labor was higher than previously reported. Women with a prolonged latent phase were more likely to receive obstetric interventions. Assisted vaginal birth was more common for nulliparous women with prolonged latent phase and emergency cesarean occurred more frequently for both nulliparous women and multiparous women with a prolonged latent phase.

Describing latent phase duration and associated characteristics among 1281 low‐risk women in spontaneous labor

“…Our duration of latent phase labor findings were similar to the estimates observed in recent European samples. For example, a study of contemporary, low‐risk Swedish women in spontaneous labor that used the woman's self‐report to identify latent phase onset found mean duration of the latent phase to be 13.9 hours' duration among nulliparous women and 10.8 hours among multiparous women . The study by Gross et al conducted in Germany that assessed low‐risk women's perceptions of the duration of latent phase vs their midwives’ perceptions of latent phase duration determined that women's estimates were similar to our study findings (median time—nulliparous, 11 hours; multiparous, 6.5 hours) .…”

Association of sedentary time and physical activity during pregnancy with maternal and neonatal birth outcomes. The GESTAFIT Project

“…We found that greater number of steps per day were associated with shorter duration of the first stage of labor, lower gestational age, and better oxygen saturation in the umbilical artery. Avoiding a prolonged duration of the first stage of labor is important, since it has been associated with more obstetric interventions, instrumented deliveries, and caesareans sections . In addition, the shorter time of cervical dilatation might have influenced the better saturation of oxygen in the umbilical artery after delivery, which is a positive sign of fetal well‐being, since uterine contractions during labor produce acute restrictions of blood flow from the placenta to the fetus .…”

Does prolonged labor affect the birth experience and subsequent wish for cesarean section among first-time mothers? A quantitative and qualitative analysis of a survey from Norway

“…However, there are other aspects of labor progression that may be of importance for the birth experience, such as the duration of early labor (cervix dilated 1-4 cm, often defined as the latent phase). A long latent phase may be associated with an increased risk of both interventions and complications, as well as a negative birth experience [30]. In the present study, the early stage of labor is taken into account, as the start of labor was defined according to the guidelines at the study hospital: a fully effaced cervix with at least 1 cm dilatation in the presence of regular, painful contractions.…”