Second-stage Labor Duration Research Articles

Current Resources for Evidence‐Based Practice January/February 2013

Current Resources for Evidence‐Based Practice January/February 2013

Budi Iman Santoso Assessment (BISA): a model for predicting levator ani injury after vaginal delivery

Background: There have been no attempts or studies to integrate various risk factors that can be utilized to predict levator ani injury caused by vaginal delivery. This study was aimed to establish an index measurement system by using various risk factors for predicting levator ani injury in vaginal delivery. Methods: A prospective cohort was conducted at two hospitals in Jakarta between 2010 and 2011. The subjects were nulipara pregnant women without levator ani injury during pregnancy and vaginal birth. Levator ani injury was evaluated using 4D USG during pregnancy and three months after delivery. The variables studied were age, body mass index, mode of delivery, fetal birth weight, episiotomy, perineum rupture and duration of second stage labor. Prediction model was analyzed using logistic regression analysis. Results: There were 182 recruited subjects of which 124 subjects were eligible and only 104 subjects could be analyzed. Incidence of levator ani injury at three months after delivery was 15.4% (95% CI: 8.6-23%). Two prediction models were obtained. The first consisted of fetal birth weight (OR= 5.36, 95% CI: 1.08-26.59), episiotomy (OR= 5.41, 95% CI: 0.94-31.18), and duration of second stage labor (OR= 15.27, 95% CI: 3.15-73.96). The second model consisted of duration of second stage labor (OR= 9.51, 95% CI: 1.23-68.10) and perineum rupture (OR= 142.70, 95% CI: 14.13-1440.78). Conclusion: Fetal birth weight, episiotomy and duration of second stage labor could predict levator ani injury for model 1; while the variables of prediction for model 2 were duration of second stage labor and perineum rupture. (Med J Indones. 2012;21:102-7)

Maternal and infant factors associated with neonatal adiposity: Results from the Tasmanian Infant Health Survey (TIHS)

To examine the maternal and neonatal factors associated with offspring adiposity and the role of birth and placental weight as potential mediators in such associations. The Tasmanian Infant Health Survey was a prospective cohort study conducted between 1988 and 1995 in Australia to investigate the cause of Sudden Infant Death Syndrome. This large infant cohort provides measurement of skinfolds on 7945 mothers and their offspring. Participants included singletons born ≥37 weeks gestation who were at high risk of sudden infant death syndrome identified through a composite score that included birth weight, maternal age, neonatal gender, season of birth, duration of second-stage labor and intention to breastfeed. Neonatal adiposity was assessed from skinfold measurements of the subscapular (SSF) and triceps folds (TSF) taken at birth. Maternal early-pregnancy body mass index (BMI) was calculated from self-reported height and weight. Neonatal data were extracted from birth records. Data relating to other environmental exposures were obtained from questionnaires administered when neonates were ∼4-days old. In multivariable models, higher maternal adiposity, increasing maternal age, gestation age, delivery by Caesarian section and female gender were associated with larger SSF independent of placental and birth weight (P<0.001). Maternal age and delivery by Caesarian section were significantly associated with larger TSF, whereas gestational age and male gender were associated with thinner TSF independent of placental and birth weight. Higher early-pregnancy BMI, maternal weight gain, maternal age, parity and gestational age were significantly associated with larger placental and birth weight. Smoking during pregnancy was associated with smaller birth weight but not with placental weight. In addition to birth weight, maternal adiposity and placental weight were important additional factors associated with neonatal adiposity.

Second-Stage Labor Duration in Nulliparous Women

Rouse, D.J.; Weiner, S.J.; Bloom, S.L.; Varner, M.W.; Spong, C.Y.; Ramin, S.M.; Caritis, S.N.; Peaceman, A.M.; Sorokin, Y.; Sciscione, A.; Carpenter, M.W.; Mercer, B.M.; Thorp, J.M.; Malone, F.D.; Harper, M.; Iams, J.D.; Anderson, G.D. Author Information

Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes

Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes

Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes

The purpose of this study was to assess maternal and perinatal outcomes as a function of second-stage labor duration. We assessed outcomes in nulliparous laboring women who were enrolled in a trial of fetal pulse oximetry. Of 5341 participants, 4126 women reached the second stage of labor. As the duration of the second stage increased, spontaneous vaginal delivery rates declined, from 85% when the duration was <1 hour to 9% when it was > or =5 hours. Adverse maternal outcomes that were associated significantly with the duration of the second stage of labor included chorioamnionitis (overall rate, 3.9%), third- or fourth-degree perineal laceration (overall rate, 8.7%), and uterine atony (overall rate, 3.9%). Odds ratios for each additional hour of the second stage of labor ranged from 1.3-1.8. Among individual adverse neonatal outcomes, only admission to a neonatal intensive care unit was associated significantly with second stage duration (odds ratio, 1.4). The second stage of labor does not need to be terminated for duration alone.

Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes

Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes

Mediolateral Episiotomy Reduces the Risk for Anal Sphincter Injury During Operative Vaginal Delivery

Injury to the anal sphincter during childbirth is accepted as a major risk factor for fecal incontinence in women. As many as 50% of women with such injury report fecal incontinence, due mainly to a persistently defective sphincter. Risk factors for anal sphincter injury during operative vaginal delivery were examined in a population-based observational study of 7478 Dutch women who had forceps delivery and 21,254 who delivered by vacuum extraction. Cases were taken from a validated Dutch national obstetrical database for the years 1994–1995. Partial sphincter injuries were included. Anal sphincter injury occurred in 646 women delivered with vacuum extraction (3.0%) and in 348 of those who had forceps delivery (4.7%). Risk factors for anal sphincter injury during delivery aided by vacuum extraction included primiparity, higher fetal birth weight, an occipitoposterior position, and the duration of the second stage of labor. Induction of labor did not appear to alter the risk. Mediolateral episiotomy during vacuum extraction had a highly protective effect, lowering the risk of a third-degree perineal tear by nearly 90% (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.09–0.13). The number of mediolateral episiotomies needed to prevent 1 anal sphincter injury after vacuum-assisted delivery was 12.4. Significant risk factors for anal sphincter damage in forceps deliveries included primiparity, occipitoposterior position, and higher fetal birth weight. The duration of second-stage labor was not a significant risk factor. As with vacuum extraction, induced labor carried no added risk. Mediolateral episiotomy correlated with a considerable reduction in the risk of anal sphincter damage (OR, 0.09; 95% CI, 0.07–0.11). The number of episiotomies needed to prevent a single sphincter injury during forceps delivery was 5.0 (95% CI, 4.4–5.7). The investigators conclude that mediolateral episiotomy should be routinely performed during operative vaginal deliveries in order to avoid injuring the anal sphincter.

Variation in the postpartum hemorrhage rate in a clinical trial of oral misoprostol

Objective. The main objective of this study was to identify factors associated with variation in the rate of acute postpartum hemorrhage (PPH), defined as blood loss ≥ 500 mL within 2 hours of delivery, observed in a randomized clinical trial of misoprostol for the prevention of PPH, conducted in rural India. Although the women in the misoprostol group had a significantly lower probability of having a PPH, we also noted a reduction in the rate of PPH in the placebo group over the course of the study. We hypothesized that this was due to the changing skills of the auxiliary nurse midwives (ANMs) over the course of the study.Methods. We conducted a post-hoc analysis examining variation in PPH rates over the duration of the trial among the women randomized to the placebo arm (n = 808). Descriptive, correlation analysis and generalized estimating equations (GEE) were used to predict PPH rates. With no direct measure of ANM skills, we used proxy measures, including: (1) the ANM's point of entry into the study (original ANMs at the initiation of the trial were less skilled than replacement ANMs); (2) the study duration, representing exposure of the ANM to ongoing training and monitoring; and (3) duration of the second stage of labor as a measure of improved delivery practices.Results. As the study duration increased, the duration of the second stage of labor decreased (−0.12, p = 0.001) and as the duration of the second stage of labor decreased, the rate of PPH decreased (0.0282; 95% CI 0.0201–0.0363). For each 10-minute increase in the duration of second stage labor increased PPH odds by 7.1% and each 30-day duration of the trial decreased PPH odds by 3.4%. Additionally, a patient delivered by an original ANM was 3.14 times more likely to have a PPH compared to a patient delivered by a replacement ANM.Conclusions. Declining PPH rates were associated with improved skills and delivery practices that decreased duration of the second stage of labor. These improvements appeared to be consistent with the introduction of the more skilled replacement ANMs as well as ongoing training and monitoring for all ANMs over the duration of the trial.

Best Practices in Second Stage Labor Care: Maternal Bearing Down and Positioning

Despite evidence of adverse fetal and maternal outcomes from the use of sustained Valsalva bearing down efforts, current second-stage care practices are still characterized by uniform directions to "push" forcefully upon complete dilatation of the cervix while the woman is in a supine position. Directed pushing might slightly shorten the duration of second stage labor, but can also contribute to deoxygenation of the fetus; cause damage to urinary, pelvic, and perineal structures; and challenge a woman's confidence in her body. Research on the second stage of labor care is reviewed, with a focus on recent literature on maternal bearing down efforts, the "laboring down" approach to care, second-stage duration, and maternal position. Clinicians can apply the scientific evidence regarding the detrimental effects of sustained Valsalva bearing down efforts and supine positioning by individualizing second stage labor care and supporting women's involuntary bearing down sensations that can serve to guide her behaviors.

Provider Support of Spontaneous Pushing During the Second Stage of Labor

To describe the association between provider communication and actual maternal pushing behavior in second-stage labor and to test differences in length of second stage and total maternal pushing time by maternal pushing behavior. Descriptive. Midwest hospital birth unit. Twenty primigravidas who gave birth vaginally. Type of provider communication (supportive of spontaneous or directed pushing). Maternal pushing behavior (spontaneous or directed) documented by videotape review. The percentage of provider communication supporting spontaneous pushing versus directed pushing and the percentage of actual spontaneous versus directed maternal pushing behavior were associated (Pearson r = .80, p = .001, for spontaneous and r = .89, p = .001, for directed). Neither duration of second stage (t = .06, p = .95) nor time spent pushing (t = .15, p = .89) differed by spontaneous versus directed pushing style. The proportion of spontaneous pushing by the birthing woman was positively and significantly associated with the proportion of caregiver communication supporting and encouraging spontaneous pushing. Importantly, spontaneous pushing did not significantly lengthen the duration of second-stage labor or total time spent pushing.

Effect of Fetal Position on Second-Stage Duration and Labor Outcome

To evaluate the effect of fetal position on 1) second-stage labor duration and 2) indicators of maternal and neonatal morbidity. A retrospective cohort study was conducted using a database from a previously reported randomized clinical trial. The data set includes 210 women with the fetus in a posterior position, 200 women with the fetus in a transverse position, and 1,198 women with the fetus in an anterior position. Mean durations of the second stage of labor for different fetal positions were compared using Tukey studentized test. A multivariate logistic regression model was performed to examine the determinants of prolonged second-stage duration (>or= 3 hours). Kaplan-Meier survival curves were used to graph and compare the duration of the second stage of labor for spontaneous delivery according to the fetal position at full dilatation and study group. Fetal malposition at full dilatation was associated with a significantly increased risk of instrumental vaginal delivery, cesarean delivery, oxytocin administration before full cervical dilatation, episiotomy, severe perineal laceration, and maternal blood loss of more than 500 mL (all P values < .01). Compared with the occiput anterior positions, there were significant differences in the duration of the second stage of labor, with a mean of 3.1 hours (95% confidence interval [CI] 3.0-3.2) for occiput anterior positions, 3.6 hours (95% CI 3.3-3.9) for occiput transverse positions (P < .05), and 3.8 hours (95% CI 3.5-4.1) for occiput posterior positions (P < .05) in the delayed pushing group. For the early pushing group, means were 2.2 hours (95% CI 2.1-2.3) for occiput anterior positions, 2.5 hours (95% CI 2.3-2.8) for occiput transverse positions (P < .05), and 3.0 hours (95% CI 2.7-3.3) for occiput posterior positions (P < .05). Fetal malposition at full dilatation results in a higher risk of prolonged second stage of labor and increases maternal morbidity indicators. II-2.

Induction to delivery time interval in patients with and without preeclampsia: a retrospective analysis.

Anecdotally, it is suggested that patients with preeclampsia have a shorter induction to delivery interval than patients without preeclampsia, despite there being no good objective evidence. A retrospective analysis of 136 primiparous, singleton, cephalic, nonassisted vaginal deliveries between January 1997 and January 2000. Sixty-eight women had induction of labor for preeclampsia and 68 women without preeclampsia had induction of labor for other reasons. The two groups were already case-matched for maternal and gestational age. The following details were recorded from the case notes: maternal age, gestation at delivery, initial Bishop score, total dose of prostaglandin administered, induction to delivery interval, duration of second-stage labor, birthweight, and the percentage of Apgar scores < 7 at 5 min. Statistical analysis was carried out with a Mann-Whitney U-test, with the aid of SPSS version 9, Microsoft Windows The women with preeclampsia had a statistically significant longer induction to delivery interval than those without preeclampsia. The mean induction to delivery interval of women with and without preeclampsia was 1049.5 min and 762.5 min, respectively (p < 0.001) Women with preeclampsia had a longer induction to delivery interval than patients without preeclampsia. This fact must be considered when deciding upon the mode of delivery in preeclamptic patients.

Adolescent pregnancy: positive perinatal outcome at a community hospital.

The objective of the present study was to determine the association between early maternal age and pregnancy outcome at a community hospital. A retrospective cohort of 188 nulliparous patients was divided into three study groups of adolescent patients and a control group based on maternal age at the time of delivery. Younger adolescents had an excellent prenatal visit record. Overall complication rates were low and similar among groups. The cesarean section rates were not higher for younger adolescents in comparison to the control group. Duration of second stage of labor was shorter in adolescents than in the older patients (34.3 +/- 39.5 vs 59.5 +/- 39.9 min; t = 3.24; p = 0.002). There were no differences in mean gestational ages at delivery. The mean birth weights were lower in all adolescent groups compared to the control (ANOVA: F = 3.729; p = 0.0124). There were few NICU admissions in adolescent groups. Early maternal age (13 to 19 years) was associated with shorter duration of second stage labor and lower birth weight in a cohort of patients delivering at a community hospital.

Effect of the Birth Chair on Duration of Second Stage Labor And Maternal Outcome

The effect of delivering in a birth chair on duration of second stage labor, perineal swelling, incidence of episiotomies, lacerations, hemorrhoids, and maternal blood loss was examined in a prospective quasi-experimental study. The sample consisted of 55 primiparous women, 37 to 41 weeks gestation, with normal pregnancy and labor; 22 delivered on a traditional delivery table (DT) and 33 in a birth chair (BC). Comparisons were made between groups for mean duration of second stage labor, mean time bearing down in the delivery room, mean maternal blood loss, frequency of instrument-assisted deliveries, frequency of episiotomies and lacerations, and frequency of perineal swelling and hemorrhoids. The two groups were statistically similar for weight of infant. No significant difference was found between groups for mean duration of second stage labor (BC M = 55 minutes, DT M = 43 minutes) or mean time bearing down (BC M = 60 minutes, DT M = 53 minutes). No difference was found in the amount of blood loss between the two groups as measured by the mean difference in the pre- and postdelivery hemoglobin (BC M change = 1.4 Gms, DT M change = 1.8 Gms). The lack of significant differences in blood loss may be due to the fact that the angle of the birth chair was lowered during or after delivery in 88% of the cases. The incidence of instrument-assisted deliveries (BC = 7, DT = 6), episiotomies (BC = 27, DT = 20), lacerations (BC = 17, DT = 5), and hemorrhoids (BC = 14, DT = 4) was similar between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the Birth Chair on Duration of Second Stage Labor, Fetal Outcome, and Maternal Blood Loss

The effect of delivering in a birth chair on duration of second stage labor, fetal outcome, and maternal blood loss was examined in a retrospective study. The sample consisted of 60 primiparous women, 37 to 41 weeks gestation with a normal pregnancy and labor, 30 delivering on a traditional delivery table and 30 delivering in a birth chair. Comparisons were made between groups for mean duration of second stage labor, mean Apgar scores at one and five minutes, and mean maternal hemoglobin and hematocrit values during the pre- and post-partum periods. No significant difference was found between delivery table and birth chair groups for mean duration of second stage labor (birth chair, X = 60 minutes versus delivery table, X = 43 minutes, t = 1.66, p = .10). Mean Apgar scores at one and five minutes were nearly identical. Statistically significant differences existed between groups in mean maternal hemoglobin and hematocrit values. Both the mean hemoglobin and the mean hematocrit upon admission were significantly higher in the birth chair group (p less than .027). However, postpartally the birth chair group had significantly lower mean hemoglobin and hematocrit values (p less than .025). These findings suggest that the birth chair, as an alternate delivery method, is safe in terms of fetal outcome but presents no advantage to the mother in terms of shorter second stage labor. Further investigation of maternal blood loss is recommended to rule out possible untoward effects.