The retained placenta

The incidence and importance of retained placenta (RP) varies greatly around the world. In less developed countries, it affects about 0.1% of deliveries but has up to 10% case fatality rate. In more developed countries, it is more common (about 3% of vaginal deliveries) but very rarely associated with mortality. There are three main types of retained placenta following the vagina delivery: placenta adherens (when there is failed contraction of the myometrium behind the placenta), trapped placenta (a detached placenta trapped behind a closed cervix) and partial accreta (when there is a small area of accreta preventing detachment). All can be treated by manual removal of placenta, which should be carried out at 30-60 minutes postpartum. Medical management is also an option for placenta adherens and trapped placenta. The need for manual removal can be reduced by 20% by the use of intraumbilical oxytocin (30 i.u. in 30 mL saline). A trapped placenta may respond to glyceryl trinitrate (500 mcg sublingually) or gentle, persistent, controlled cord traction.     

The effects of sequential use of oxytocin and sublingual nitroglycerin in the cases of retained placenta

Objectives: To evaluate the effects of adding sublingual nitroglycerin to oxytocin, for delivery of retained placenta after vaginal delivery.

Method: The study was performed as a placebo controlled clinical trial on women who did not finish delivering placenta after 30 min of active management of the third stage of labor. In case group, 1 mg nitroglycerin and in the control group, placebo was prescribed sublingually.

Results: In total, 80 women finished the study. The number of manual removal of placenta did not show significant difference between the two groups [25 women (62.5%) in the case and 30 women (75%) in the control group, p?=?0.335]. There was no significant difference between the two groups according to duration of the third stage of labor, hemoglobin index, decline in HB index?>30% and maternal vital signs after treatment. There was no significant difference between the two groups according to adverse effects [eight women (20%) in the case group and four (10%) in the control group (p?=?0.348)].

Conclusion: The sequential use of oxytocin and sublingual nitroglycerin could not lead to delivery of more placentas and did not reduce the necessity of manual removal of placenta in comparison with placebo.     

Different routes and forms of uterotonics for treatment of retained placenta: a randomized clinical trial*

Objectives: To compare between three different uterotonics (oxytocin, carbetocin and misoprostol) given via three different routes (intraumbilical, intravenous and sublingual, respectively) in reducing the need for manual removal of placenta (MROP).

Methods: A randomized trial for cases with retained placenta 30?min following vaginal delivery. They received intraumbilical oxytocin, intravenous carbetocin or sublingual misoprostol. Main outcome measures were delivery of the placenta within 30?min following drug administration, and need for MROP. Secondary outcome measures were injection to placental delivery time, post-delivery hemoglobin, need for blood transfusion or additional uterotonics.

Results: The overall success rate was 66.7% (64/96), 71.3% (67/94) and 63.7% (58/91) for oxytocin, carbetocin and misoprostol groups, respectively (p?>?0.05). When time needed to achieve placental delivery considered, a significant difference was observed with the shortest time for carbetocin (16.61?±?3.76?min), then oxytocin (18.28?±?3.34?min) and lastly misoprostol (23.00?±?3.38?min) (p?<0.001). Again, carbetocin group needed less additional uterotonics to achieve adequate uterine contractions (p?<0.001).

Conclusions: Although we aimed to exploit the advantage of certain drug over another, all seemed to have close efficacy but it would be important that further research should highlight availability, cost, ease of administration and storage requirements to determine which agent would best be used in this clinical scenario.     

Previous history of surgically induced abortion and complications of the third stage of labour in subsequent normal vaginal deliveries

Objective. To estimate the risk of complications of the third stage of labour needing manual revision of uterine cavity or curettage in deliveries following one or multiple induced abortions in nulliparous women who had singleton live births in Estonia in 1994–2002.

Methods. Registry study using the data from the Estonian medical birth registry: 32,652 women had not had any abortions, 7333 women had had one and 2383 women had had two or more surgically induced abortions before their first delivery. Multiple logistic regression analysis was performed to estimate crude odds ratios (OR), adjusted ORs and their 95% confidence intervals, with women having had no abortions as the reference group. Adjustment was made for maternal age, sex and weight of infant, labour induction/augmentation.

Results. In the single abortion group, the crude OR was 1.25 (95% confidence intervals (CI) 1.12–1.40), the adjusted OR was 1.23 (95% CI 1.10–1.38); in the multiple abortion group the crude OR was 1.28 (95% CI 1.06–1.53), the adjusted OR was 1.24 (95% CI 1.03–1.49).

Conclusions. Our findings suggest a positive association between one or more first trimester abortion(s) and the risk of complications in the third stage of labour in subsequent singleton delivery.     

Uterine activity during the two hours after placental delivery among low-risk pregnancies: an observational study

Objective: The purpose of this study was to describe uterine activity within the first two hours after placental delivery among low-risk pregnant women.

Materials and methods: Participants were 17 low-risk pregnant women who had a singleton birth at midwifery birth centers in Japan. Contractile waves of uterine activity were measured by using an external tocodynamometer.

Results: Spontaneous uterine contraction frequency during the first two hours after the placental delivery decreased over time (F_9,?54?=_?19.7, p?<?0.001). The mean contraction intervals were 1.9?±?0.3?min, 2.4?±?0.9?min, 4.2?±?0.7?min and 7.9?±?2.1?min for the second stage, third stage, and the first hour and second hour after placental delivery, respectively. Uterine contraction frequency increased with oxytocin administration and infant suckling; however, an icepack to cool the uterus did not change the contraction waves. No correlations were found between uterine activity and blood loss or pain.

Conclusion: Contraction of the myometrium is the primary mechanism for hemostasis. The uterine contraction intervals became prolonged over time, and blood loss did not increase. The findings provide insight into the role of myometrium contraction as a hemostasis mechanism.     

Policies for manual removal of placenta at vaginal delivery: variations in timing within Europe

The length of the third stage of labour is a potential modifiable risk factor for postpartum haemorrhage at vaginal delivery, but there is no definitive evidence that early intervention to remove the placenta manually will prevent postpartum haemorrhage. We report a wide variation between countries in Europe in policies about the timing of manual removal of placenta. Two groups of countries with clearly divergent policies were identified. A randomised controlled trial is needed to provide definitive evidence on the risks and benefits of manual removal of placenta at different timings after vaginal delivery.     

Benefits of cord blood collection in the prevention of post-partum hemorrhage: a cohort study

Objective: The aim of this study was to assess the benefit of umbilical cord drainage through cord blood collection (CBC) for the prevention of post-partum hemorrhage (PPH).

Methods: This is a retrospective cohort study based on data collected prospectively including all vaginal delivery of singletons pregnancies after 37 weeks of gestation between July 2011 and May 2013 at the Strasbourg Teaching Hospital. We performed a univariate comparison of PPH risk factors with χ² tests and then we built multivariate logistic regressions to predict PPH, severe PPH (>1000?cc), retained placenta over 30?min and manual removal of the placenta.

Results: A total of 7810 vaginal deliveries were analyzed, among which 1957 benefited from CBC (25%). In the CBC group, 71 PPH (3.6%) were observed versus 260 (4.4%) in the control group (p?=?0.12). In multivariate analysis, after adjustment on PPH risk factors, CBC revealed to be a protective factor of PPH: OR?=?0.69 (95% CI 0.50–0.97; p?=?0.03). CBC is neither a significant predictive factor of severe PPH, time to placental delivery nor rate of manual removal of the placenta.

Conclusions: In our study, CBC and thus umbilical cord drainage was a protective factor against PPH but it did reduce neither retained placenta nor the need for artificial placental delivery.     

Length of the third stage of labor at term pregnancies is shorter if placenta is located at fundus: prospective study

AIM: To investigate how the location of the placenta at term pregnancies affects the duration of the third stage of labor and to discuss the possible mechanisms affecting the duration of the third stage. We believe that this is the first prospective study comparing the duration of the third stage of labor according to placental location. METHODS: The placental implantation was determined as anterior (n = 78), posterior (n = 59), or fundal (n = 64) by ultrasound, in 201 women with singleton pregnancies. After delivery of the newborn, oxytocin infusion was routinely given. Duration of the third stage of labor was compared by anova. P < 0.05 was determined as significant. RESULTS: The duration of the third stage of labor was 10.36 +/- 5.94 min, 10.44 +/- 5.35 min, and 8.12 +/- 4.25 min with placentas located anteriorly, posteriorly, and fundal, respectively. The length of the third stage was significantly shorter in the fundal placenta group. CONCLUSION: In this study, the length of the third stage of labor was approximately 2 min shorter with placentas located at the fundus compared to the other two groups. The mechanism responsible for shorter duration may be the bipolar separation of fundal placentas in contrast to usual unipolar down-up separation of anterior or posterior placentas. Another contributing factor may be the use of oxytocin infusion for the management of the third stage, however this should be investigated by further studies by using real time ultrasonography.     

Pre-delivery remifentanil infusion for placenta accreta cesarean delivery under general anesthesia: an observational study

Objective: General anesthesia may be required for placenta accreta cesarean delivery. Intrauterine fetal anesthetic exposure should be minimized to avoid neonatal respiratory depression; opioids are often delayed until post-delivery.

Methods: In this observational study, we compared neonatal outcome using pre-delivery remifentanil versus post-delivery (deferred) opioids for placenta accreta cesarean delivery. Choice of anesthesia was discretionary. The primary outcome was Apgar score at 5?min comparing women who received pre-delivery remifentanil versus deferred opioid administration. We recorded maternal/obstetric characteristics, surgical characteristics, maternal hemodynamic data, neonatal outcomes: Apgar scores, umbilical vein pH and respiratory interventions at birth.

Results: Between February 2007 and April 2014 we identified 40 general anesthesia placenta accreta cesarean deliveries. The remifentanil dose rate ranged from 0.06 to 0.46 mcg?kg^?1?min^?1. Obstetric and maternal characteristics were similar. Neonatal Apgar, umbilical pH and respiratory intervention outcomes were similar in both groups; Apgar scores median (interquartile range IQR [range]) at 5?min were 9 (8–10) for pre-delivery remifentanil versus 9 (9–10) for deferred opioid administration, p?=?0.18.

Conclusions: We did not observe a significant effect on neonatal Apgar scores at 1 and 5?min, or respiratory interventions at birth when remifentanil infusion was administered pre-delivery.     

前置胎盘合并剖宫产史临床分析

目的探讨前置胎盘合并剖宫产史患者的临床特点及处理。方法回顾性分析2003年1月至2011年10月北京协和医院前置胎盘合并剖宫产史（再次剖宫产组,RCS组）患者母婴结局,并与同期前置胎盘行初次剖宫产（初次剖宫产组,FCS组）进行比较。结果 RCS组及FCS组分别有29例及243例患者。两组的平均年龄、孕周差异无统计学意义（P〉0.05）。RCS组患者手术时间长,产后出血量多,早产、产后出血、胎盘植入、输血、弥漫性血管内凝血和产科子宫切除的发生率均高于FCS组,差异有统计学意义（P〈0.05）,RCS组早产儿、新生儿窒息发生率及围产儿死亡率均高于FCS组（P〈0.05）。结论前置胎盘合并剖宫产史更易发生胎盘植入,产后出血、产科子宫切除及围产儿病率高,需要高度重视。     

Association of caesarean delivery for first birth with placenta praevia and placental abruption in second pregnancy

Objective  To quantify the risk of placenta praevia and placental abruption in singleton, second pregnancies after a caesarean delivery of the first pregnancy.
Design  Retrospective cohort study.
Setting  Linked birth and infant mortality database of the USA between 1995 and 2000.
Population  A total of 5 146 742 singleton second pregnancies were available for the final analysis after excluding missing information.
Methods  Multiple logistic regressions were used to describe the relationship between caesarean section at first birth and placenta praevia and placental abruption in second-birth singletons.
Main outcome measures  Placenta praevia and placental abruption.
Results  Placenta praevia was recorded in 4.4 per 1000 second-birth singletons whose first births delivered by caesarean section and 2.7 per 1000 second-birth singletons whose first births delivered vaginally. About 6.8 per 1000 births were complicated with placental abruption in second-birth singletons whose first births delivered by caesarean section and 4.8 per 1000 birth in second-birth singletons whose first births delivered vaginally. The adjusted odds ratio (95% CIs) of previous caesarean section for placenta praevia in following second pregnancies was 1.47 (1.41, 1.52) after controlling for maternal age, race, education, marital status, maternal drinking and smoking during pregnancy, adequacy of prenatal care, and fetal gender. The corresponding figure for placental abruption was 1.40 (1.36, 1.45).
Conclusion  Caesarean section for first live birth is associated with a 47% increased risk of placenta praevia and 40% increased risk of placental abruption in second pregnancy with a singleton.     

Prospective randomized trial of oxytocin administration for active management of the third stage of labor

Objective

To determine the most efficient route and timing of oxytocin administration for active management of the third stage of labor.

Methods

A prospective randomized study was done at one center in Ankara, Turkey, between January and October 2010. Women with a singleton pregnancy (> 37 weeks) who had a live vaginal birth were randomly allocated to four groups: iv-A (intravenous oxytocin after delivery of the fetus), iv-B (when anterior shoulder seen), im-A (intramuscular oxytocin after delivery), and im-B (when anterior shoulder seen). Postpartum blood loss within the first hour, hemoglobin, hematocrit, and duration of the third stage were compared.

Results

A total of 600 eligible women were recruited; 150 were assigned to each group. Postpartum blood loss, prepartum and postpartum hemoglobin and hematocrit, and need for additional uterotonics were similar among groups (P > 0.05). The duration of the third stage of labor and changes in hemoglobin and hematocrit were significantly reduced in group iv-B (P < 0.05). Among women not exposed to oxytocin before delivery, postpartum blood loss was significantly lower in group iv-B (P = 0.019). Labor augmentation was related to significantly increased postpartum blood loss in all groups except iv-A.

Conclusion

Although postpartum blood loss was similar in all groups, early intravenous administration seemed to have beneficial effects.ClinicalTrials.gov: NCT01954186.     

Timing of placental delivery to prevent post-partum haemorrhage: lessons learned from an abandoned randomised clinical trial

It has been recognised that, if the length of the third stage of labour exceeds 30 min, then there is an increased risk of a post-partum haemorrhage. Recent information has suggested that 18 min is the optimal time for removal of the undelivered placenta to prevent a post-partum haemorrhage. A randomised trial comparing 20 vs. 30 min was stopped after an interim analysis because only eight of 1607 patients' placentas had not delivered by 20 min. A third stage of labour that exceeded 10 min was observed to be significantly correlated with an increased risk of post-partum haemorrhage.     

Afterpains: A Comparison Between Active and Expectant Management of the Third Stage of Labor

Abstract: Background: Management of the third stage of labor, the period following the birth of the infant until delivery of the placenta, is crucial. Active management using synthetic oxytocin has been advocated to decrease blood loss. It has been suggested, but not studied, that oxytocin may increase afterpains. The aim of this study was to compare women’s experience of pain intensity when the third stage of labor was managed actively and expectantly and their experience of afterpains. Methods: A single‐blind, randomized, controlled trial was performed at two delivery units in Sweden in a population of healthy women with normal, singleton pregnancies, gestational age of 34 to 43 weeks, cephalic presentation, and expected vaginal delivery. Women (n = 1,802) were randomly allocated to either active management or expectant management of the third stage of labor. Afterpains were assessed by Visual Analog Scale (VAS) and the Pain‐o‐Meter (POM‐WDS) 2 hours after delivery of the placenta and the day after childbirth. Results: At 2 hours after childbirth, women in the actively managed group had lower VAS pain scores than expectantly managed women (p = 0.014). Afterpains were scored as more intense the day after, compared with 2 hours after, childbirth in both groups. Multiparas scored more intense afterpains, compared with primiparas, irrespective of management (p < 0.001). Conclusions: Active management of the third stage of labor does not provoke more intense afterpains than expectant management. (BIRTH 38:4 December 2011)     

International Session Award. Non-invasive cutaneous cardiovascular dynamics (CVD) as a predictor of preterm delivery: a pilot study

AIM: To assess the clinical value of cardiovascular dynamics (CVD) pattern of 'positive cycling' in predicting true preterm labor. METHODS: Patients with a clinical diagnosis of preterm labor had CVD measurement with a non-invasive miniature pressure transducer applied to the fingertip concomitantly with uterine activity monitoring. Based on previous work by our group, the rapid ejection time (RET) reflects arterial compliance; an elevated RET is suggestive of vasoconstriction. Positive cycling is present when the RET shows elevation with uterine contractions and negative cycling is present when there are no changes in the RET with uterine contractions. RESULTS: Twenty-seven women had negative CVD cycling and nine had positive CVD cycling. There was no difference between the two groups in initial gestational age, cervical effacement or cervical dilation at testing. However, the mean interval from testing to delivery was 1.56 (SEM+/-0.29) days for positive cycling and 39 days (+/-5.25) for negative cycling (P < 0.001). CONCLUSION: Non-invasive cardiovascular patterns of positive cycling appear predictive of preterm delivery.