Labor estimation by informational objective assessment (LEIOA) for preterm delivery prediction.

PURPOSE: To introduce LEIOA, a new screening method to forecast which patients admitted to the hospital because of suspected threatened premature delivery will give birth in < 7 days, so that it can be used to assist in the prognosis and treatment jointly with other clinical tools. METHODS: From 2010 to 2013, 286 tocographies from women with gestational ages comprehended between 24 and 37 weeks were collected and studied. Then, we developed a new predictive model based on uterine contractions which combine the Generalized Hurst Exponent and the Approximate Entropy by logistic regression (LEIOA model). We compared it with a model using exclusively obstetric variables, and afterwards, we joined both to evaluate the gain. Finally, a cross validation was performed. RESULTS: The combination of LEIOA with the medical model resulted in an increase (in average) of predictive values of 12% with respect to the medical model alone, giving a sensitivity of 0.937, a specificity of 0.747, a positive predictive value of 0.907 and a negative predictive value of 0.819. Besides, adding LEIOA reduced the percentage of incorrectly classified cases by the medical model by almost 50%. CONCLUSIONS: Due to the significant increase in predictive parameters and the reduction of incorrectly classified cases when LEIOA was combined with the medical variables, we conclude that it could be a very useful tool to improve the estimation of the immediacy of preterm delivery.

Estimation of preterm labor immediacy by nonlinear methods.

Preterm delivery affects about one tenth of human births and is associated with an increased perinatal morbimortality as well as with remarkable costs. Even if there are a number of predictors and markers of preterm delivery, none of them has a high accuracy. In order to find quantitative indicators of the immediacy of labor, 142 cardiotocographies (CTG) recorded from women consulting because of suspected threatened premature delivery with gestational ages comprehended between 24 and 35 weeks were collected and analyzed. These 142 samples were divided into two groups: the delayed labor group (n = 75), formed by the women who delivered more than seven days after the tocography was performed, and the anticipated labor group (n = 67), which corresponded to the women whose labor took place during the seven days following the recording. As a means of finding significant differences between the two groups, some key informational properties were analyzed by applying nonlinear techniques on the tocography recordings. Both the regularity and the persistence levels of the delayed labor group, which were measured by Approximate Entropy (ApEn) and Generalized Hurst Exponent (GHE) respectively, were found to be significantly different from the anticipated labor group. As delivery approached, the values of ApEn tended to increase while the values of GHE tended to decrease, suggesting that these two methods are sensitive to labor immediacy. On this paper, for the first time, we have been able to estimate childbirth immediacy by applying nonlinear methods on tocographies. We propose the use of the techniques herein described as new quantitative diagnosis tools for premature birth that significantly improve the current protocols for preterm labor prediction worldwide.

Induction of labor in breech presentation at term: a retrospective cohort study.

OBJECTIVE: To compare the outcome of two methods of labor induction and spontaneous onset of labor in breech presentation at term. MATERIAL: A retrospective study between 2003 and 2012. We compare obstetric (indication of induction, Bishop score, cesarean rate) and perinatal outcomes (Apgar score, umbilical artery pH, base excess ≤-12 mmol/L, admission to neonatal unit) between prostaglandins and oxytocin. We also compare labor induction versus spontaneous onset of labor. RESULTS: Of the 1684 breech deliveries, we carried out labor induction in 221 cases (76% with prostaglandins, 24% with oxytocin). The prostaglandins group had significantly lower Bishop scores and the time for induction phase was significantly higher. There were no differences in cesarean rate between both methods of induction or spontaneous onset of labor. The prostaglandins group had higher rates of base excess ≤-12 mmol/L. Compared with spontaneous onset of labor in breech presentation, induction had significant lower rates of newborn weight and higher rates of admission to the neonatal unit. CONCLUSIONS: Induction of labor in breech presentation at term is a reasonable and effective option after a careful selection of cases. It was not associated with an increase of perinatal morbidity or cesarean rate compared with spontaneous onset of labor.

Increased pain relief with remifentanil does not improve the success rate of external cephalic version: a randomized controlled trial.

INTRODUCTION: Our objective was to compare the effect of two pain relief methods (remifentanil vs. nitrous oxide) on the success rate of external cephalic version. MATERIAL AND METHODS: We conducted a randomized open label parallel-group controlled single-center clinical trial with sequential design, at Cruces University Hospital, Spain. Singleton pregnancies in noncephalic presentation at term that were referred for external cephalic version were assigned according to a balanced (1:1) restricted randomization scheme to analgesic treatment with remifentanil or nitrous oxide during the procedure. The primary endpoint was external cephalic version success rate. Secondary endpoints were adverse event rate, degree of pain, cesarean rate and perinatal outcomes. RESULTS: The trial was stopped early after the second interim analysis due to a very low likelihood of finding substantial differences in efficacy (futility). The external cephalic version success rate was the same in the two arms (31/60, 51.7%) with 120 women recruited, 60 in each arm. The mean pain score was significantly lower in the remifentanil group (3.2 ± 2.4 vs. 6.0 ± 2.3; p < 0.01). No differences were found in external cephalic version-related complications. There was a trend toward a higher frequency of adverse effects in the remifentanil group (18.3% vs. 6.7%, p = 0.10), with a significantly higher incidence rate (21.7 events/100 women vs. 6.7 events/100 women with nitrous oxide, p = 0.03). All reported adverse events were mild and reversible. CONCLUSIONS: Remifentanil for analgesia decreased external cephalic version-related pain but did not increase the success rate of external cephalic version at term and appeared to be associated with an increased frequency of mild adverse effects.

Probability of cesarean delivery after successful external cephalic version.

OBJECTIVE: To identify factors associated with cesarean delivery following successful external cephalic version (ECV). METHODS: In a prospective study, data were obtained for ECV procedures performed at Cruces University Hospital, Spain, between March 2002 and June 2012. Women with a singleton pregnancy who had a successful, uncomplicated ECV and whose delivery was assisted at the study hospital, with the fetus in cephalic presentation, were included. A multivariate model of risk factors of cesarean delivery was developed. RESULTS: Among 627 women included, 92 (14.7%) delivered by cesarean. A cesarean was performed among 33 (8.5%) of 387 women with spontaneous labor versus 59 (24.6%) of 240 who were induced (P < 0.001). Multivariate analysis showed that higher BMI (P = 0.006), labor induction (P = 0.001), and prior cesarean (P < 0.001) were associated with cesarean. Time between ECV and delivery was inversely associated with probability of cesarean during the first 2 weeks. Thus, the probabilities of cesarean delivery on the first day were 0.53 (95% CI 0.35-0.71) and 0.34 (95% CI 0.18-0.51) following induced and spontaneous labor, respectively. On the seventh day, the probabilities were 0.23 (95% CI 0.15-0.32) and 0.12 (95% CI 0.07-0.18), respectively. CONCLUSION: Following ECV, induction of labor, an interval of less than 2 weeks to delivery, BMI, and previous cesarean were associated with an increased risk of cesarean.

Nitrous oxide for analgesia in external cephalic version at term: prospective comparative study.

OBJECTIVE: The objective of this study was to analyze the effect of using inhaled nitrous oxide (N2O) for analgesia in external cephalic version (ECV) at term on the success rate of the procedure, on pain, and on obstetric and perinatal outcomes. METHODS: A prospective comparative cohort study among 300 women with singleton pregnancy in breech presentation at term undergoing an ECV with inhaled N2O in a 50:50 mix with oxygen for analgesia and 150 ECVs with no analgesia. RESULTS: The success rate was 52.3% in the N2O cohort and 52.7% in the controls (P=0.94), whereas the median level of pain was statistically lower in women given N2O (median, 6; range, 4-7, vs. median, 7; range, 5-8; P<0.01). This improvement is mainly from a 49% decrease in severe pain. There were no significant differences in the rate of complications associated with the ECV, in the rate of cesarean sections, or in perinatal outcomes. Furthermore, there were no severe complications secondary to N2O inhalation. CONCLUSIONS: N2O inhalation at a concentration of 50% for analgesia during ECV decreases the level of severe pain experienced by women, appears to be safe both for mother and child, and has no influence on the success rate of ECV or the perinatal outcomes.

Influence of chorionicity in intra-partum management of twin deliveries.

OBJECTIVE: To analyze morbidity and mortality in twin pregnancies as a function of the type of delivery and chorionicity. DESIGN: Retrospective cohort study. METHODS: Analysis of the type of delivery, intertwin time interval, and perinatal variables of >1000 twin deliveries during a 10-year period. MAIN OUTCOME MEASURE: Influence of delivery type and chorionicity on perinatal outcome. RESULTS: The rate of cesarean sections was 42.4%. No differences were found as a function of chorionicity or as a function of presentation of the second twin. Cesarean sections were performed after vaginal delivery of the first twin in 1.8% of cases, being more common if the second baby was in a non-cephalic presentation (6.9% vs. 0.4%, p < 0.05). The average twin-to-twin delivery time interval was longer in the cases where the second had a cephalic presentation (8.26 ± 7.75 min vs. 6.81 ± 5.97 min, p < 0.05). The umbilical artery pH was lower the longer the interval between the birth of the twins, both in monochorionic and dichorionic. CONCLUSIONS: According to the results, vaginal delivery is as safe as elective caesarean section in twin pregnancies where the first twin is in cephalic presentation and the intrapartum management should not vary due to chorionicity.

Induction at 41 weeks increases the risk of caesarean section in a hospital with a low rate of caesarean sections.

OBJECTIVE: To analyse the impact of a change in the management of prolonged pregnancies from inducing labour at 42(+0) to induction at 41(0-6). DESIGN: Retrospective cohort study. METHODS: Analysis of 3563 single pregnancies with cephalic presentation of ≥ 41 weeks of gestation delivered in Cruces University Hospital (Spain). Two cohorts were compared corresponding to before and after the change in the policy on induction. MAIN OUTCOME MEASURES: Induction rate, vaginal delivery rate, newborn morbidity and mortality. RESULTS: The overall rate of caesarean sections in the patients included in the study was 12.8% (19.5% among those induced and 8.4% among those in whom the onset of labour has been spontaneous). The caesarean section rate in cohorts 41(0-6) and 42(+0) were 14.1% and 11.4%, respectively (p=0.01). Though there were more newborns with umbilical cord blood ph<7.10 in cohort 41(0-6) than in the other group (8.7% versus 4.5%; p<0.01), no significant differences were found between cohorts in 5-min Apgar score < 7, number of admissions to the neonatal care unit or perinatal mortality. CONCLUSION: The induction of labour during week 41 in prolonged pregnancies may increase the rate of caesarean sections in hospitals with low rates of caesarean sections.

Clinical score for the outcome of external cephalic version: a two-phase prospective study.

AIM: To design a score based on clinical parameters to predict the outcome of external cephalic versions (ECVs) at term. MATERIALS AND METHODS: A two-phase study was conducted (analysis/design and prospective validation) regarding 1000 versions performed between March 2002 and November 2010. The variables considered in the score were selected based on the results of multiple logistic regression models and multiple correspondence analyses published by our group. The predictive capacity was estimated through the area under the ROC curve. RESULTS: The success rates for ECV in phases 1 and 2 were 52.2 and 51.2%, respectively, making the overall success rate 51.7%. The score was designed with the variables parity, placental location, breech variety and amount of amniotic fluid giving a value for each one. A clinical recommendation, based on the result of the score, was the estimated success rate with the 95% confidence interval. The predictive capacity of the score for the outcome of ECV at term was 70.1% (95% CI 66.9-73.4). CONCLUSIONS: A score composed of four easily measurable variables enabled us to predict the outcome of ECV at term.

Oxytocin versus dinoprostone vaginal insert for induction of labor after previous cesarean section: a retrospective comparative study.

OBJECTIVE: To compare the efficacy and safety of two methods for induction of labor after previous cesarean section. METHODS: To compare 247 women with a previous cesarean section who were induced with a dinoprostone vaginal insert and 279 women with a previous cesarean section induced with oxytocin, between 2001 and 2008. We evaluated vaginal delivery rate, maternal morbidity and newborn morbidity and mortality. RESULTS: The overall rate of vaginal delivery was 65.2%. We did not find significant differences between induction with dinoprostone vaginal insert and oxytocin in the rate of cesarean section performed (35.6% vs. 34.1%, P=0.71). There were nine cases of uterine rupture (rate of 1.7%), of which four occurred with dinoprostone vaginal insert and five when using oxytocin (P=0.89). We found no significant differences in neonatal outcomes. CONCLUSIONS: Both tested methods appear to be equally safe and effective for induction of labor in women with a previous cesarean section.

Episodios aparentemente letales en las primeras dos horas de vida durante el contacto piel con piel. Incidencia y factores de riesgo / Apparently life-threatening episodes in the first two hours of life during skin-to-skin mother-infant contact. Incidence and risk factors

Objetivo. Valorar un incremento inesperado de la incidencia en nuestro Hospital de episodios aparentemente letales en recién nacidos en las primeras 2 horas de vida. Esto ha sucedido en los 2 últimos años desde que el contacto piel con piel madre-hijo se estableció como práctica habitual. Métodos. Se ha realizado una valoración completa de los datos de todos los pacientes para detectar posibles factores de riesgo. También se ha analizado la diferente incidencia en cuatro periodos sucesivos a lo largo de los últimos 35 años con 208.220 nacidos vivos. Resultados. En el último periodo el aumento de incidencia de estos sucesos ha sido estadísticamente significativa. Se han detectado varios factores potenciales de riesgo: contacto piel con piel, primiparidad, incidencia aumentada durante la noche y suceder en el segundo periodo de adaptación neonatal (30 a 90 minutos de vida). Dos de nuestros 8 pacientes tienen secuelas neurológicas y otro de ellos murió. Conclusión. Los episodios aparentemente letales en las primeras 2 horas de vida son poco frecuentes, pero sus consecuencias pueden ser graves. El contacto piel con piel entre la madre y el neonato en la sala de partos durante el periodo de adaptación neonatal precoz puede constituir uno de los principales factores de riesgo. En tanto que el contacto piel con piel se ha mostrado beneficioso y sin riesgos aparentes, debemos estimular su práctica. Pero deberíamos garantizar la preparación del equipo y la atención durante su transcurso, especialmente si la madre está sola o concurren otros factores de riesgo(AU)

Objective. To evaluate an unexpected increase in the incidence of apparently life threatening events and sudden deaths in neonates during the first 2hours after birth in our hospital. This increase occurred in the first 2 years after generalized skin-to-skin contact between mother and infant became routine practice. Methods. Full information on all our patients was collected to evaluate possible risk factors. Differences in incidence in four successive periods comprising the previous 35 years, with 208220 live neonates, were also analyzed. Results. In the last period, there was a statistically significant increase in the rate of apparently life threatening events and sudden deaths in neonates. Several potential risk factors were detected: skin-to-skin contact, primiparity, an increased incidence in night hours and the invariable occurrence of these events in the second period of neonatal adaptation (30 to 90minutes of life). Of eight patients with apparently life-threatening events, two had neurological sequelae and another died. Conclusion. Apparently life threatening events in the first 2hours of life are uncommon but may have serious consequences. One of the main risk factors may be skin-to-skin contact between mother and infant in the delivery room during the early adaptation period. As such contact has been proven to be beneficial and without apparent risks, this practice should be promoted. However, maternity staff should be vigilant during skin-to-skin contact, especially if the mother is alone with her neonate or other risk factors are present(AU)

A prospective study of the factors associated with the success rate of external cephalic version for breech presentation at term.

OBJECTIVE: To determine the factors associated with the success rate of external cephalic version (ECV) for breech presentation at term. METHODS: A prospective analysis of 500 ECV maneuvers. The variables maternal age, maternal weight, body mass index, previous cesarean delivery, gestational age, parity, amount of amniotic fluid, placental location, and type of breech were studied using logistic regression analysis. RESULTS: The success rate of ECV was 52.2% (n=261). The variables significantly associated with success were parity, placental location, amount of amniotic fluid, and type of breech (P<0.05). A parity of 2 had a 3.74-times higher probability of success than nulliparity (95% CI, 2.37-5.90); a posterior placenta increased the success rate by 2.85 times compared with an anterior placenta (95% CI, 1.87-4.36); and double footling breech presentation had a 2.77-times higher success rate compared with a frank breech presentation (95% CI, 1.16-6.62). The area under the ROC curve showed a predictive ability of 73.6% (95% CI, 69.2%-77.9%) for these 3 variables. CONCLUSION: Parity, placental location, amount of amniotic fluid, and type of breech presentation were associated with the success rate of ECV.

Atosiban vs. ritodrine as a tocolytic in external cephalic version at term: a prospective cohort study.

OBJECTIVE: To compare the success rate of external cephalic version (ECV) at term using ritodrine or atosiban as a tocolytic agent. STUDY DESIGN: Prospective cohort study with a sample of 236 pregnant women with a breech presentation at term, from November 2006 to March 2008. Data have been analyzed from the moment the cephalic version is performed until the time of delivery. RESULTS: ECV success rate using ritodrine as a tocolytic agent was 56.8% compared to 31.4% with atosiban. Ritodrine increases the version success potential more significantly than atosiban (P<0.05). In both cases, the use of ECV reduced the rate of cesarean sections, although a higher number of versions are required with atosiban [numbers needed to treat (NNT)=9.08] to avoid a cesarean section compared to ritodrine (NNT=3.41). CONCLUSIONS: Ritodrine seems better than atosiban as tocolytic agent for ECVs.

Análisis del dolor en la versión cefálica externa / Analysis of pain in external cephalic version

Objetivo: Analizar el dolor materno durante la versión cefálica externa. Material y métodos: Estudio prospectivo en 71 pacientes, en el Hospital de Cruces, entre abril de 2005 y abril de 2006, mediante una encuesta personal tras la versión. Esta incluía una «escala numérica» de evaluación del dolor, así como preguntas relacionadas con el procedimiento. Se han analizado los resultados en función del éxito o fracaso del procedimiento. Resultados: La tasa de éxito global fue del 50,7%. Todas las gestantes lo toleraron bien y no hubo ninguna complicación. La mediana global de dolor fue 7; fue 5 en las versiones con éxito frente a 8 en las que fracasó (p < 0,01). El 83,1% repetiría el procedimiento; siendo más del 50% por el beneficio del parto en cefálica. Conclusiones: La versión cefálica externa es un procedimiento bien tolerado, probablemente debido a su brevedad, si bien es un procedimiento no exento de dolor (AU)

Objective: To analyze the maternal perception of pain during external cephalic version. Material and methods: A prospective study was carried out on 71 patients at the Hospital de Cruces between April 2005 and April 2006, based on personal surveys conducted after the version. These surveys included a «numeric pain intensity rating scale» as well as a series of questions regarding the procedure. Results were analyzed in terms of success or failure of the procedure. Results: The overall success rate was 50.7%. The procedure was well tolerated by all pregnant women, with no complications being observed. The overall median pain stood at 7; 5 in successful versions, as opposed to 8 in unsuccessful versions (P<.01). A total of 83.1% of patients stated that they would be willing to undergo the procedure again in the future, more than 50% of them basing their decision on the benefits of cephalic delivery. Conclusions: The fact that external cephalic version is a well tolerated procedure is probably due to its brevity, although it must be noted that it is not a pain-free maneuver (AU)

Does fetal weight estimated by ultrasound really affect the success rate of external cephalic version?

OBJECTIVE. To determine whether fetal weight estimated by ultrasound on the day the external cephalic version (ECV) is related to the procedure's success rate. DESIGN. Retrospective cohort study. Setting. University hospital. POPULATION OR SAMPLE. Two hundred women with a singleton pregnancy undergoing an ECV attempt between March 2002 and March 2006. METHOD. Projected birthweight at delivery was calculated. Logistic regression analysis, by grams and by weight intervals, and multiple correspondence analysis were performed to determine whether or not the weight was related to the procedure's success. Specific statistical analysis was undertaken to minimize measurement bias in fetal weight estimation. MAIN OUTCOME MEASURE. Success of ECV in relation to estimated fetal weight. RESULTS. Measurement bias was ruled out because no statistically significant differences were identified with the Student's t-test (p>0.05), Bland-Altman's agreement analysis, and the interclass correlation coefficient analysis (ICC = 0.829; CI95% 0.772-0.871; p<0.01). By logistic regression analysis, a variable relation between fetal weight estimated by ultrasound and ECV success was detected, while multiple correspondence analysis suggested that variations in fetal weight are weakly related to the procedure's success or failure. No relation was identified between ECV and birthweight (p = 0.38) when the delivery took place in the same week as the version. CONCLUSIONS. Estimated fetal weight before ECV seems not to be related to the outcome of ECV.