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.     

Intra-umbilical vein injection and retained placenta: evidence from a collaborative large randomised controlled trial

Objective To determine whether intra-umbilical vein injection with saline solution, with or without oxytocin, reduces the need for manual removal of placenta compared with expectant management.
Design Multicentre, randomised controlled trial.
Setting Eleven hospitals in four cities of Argentina: Buenos Aires, Corrientes, Rosario, and Salta.
Participants Two hundred and ninety-one women showing no evidence of placental separation thirty minutes after vaginal delivery.
Interventions Three different management strategies: 1. intra-umbilical vein injection of saline solution plus oxytocin; 2. intra-umbilical vein injection of saline solution alone; and 3. expectant management.
Main outcome measures Primary: manual removal of the placenta. Secondary: blood loss after trial entry, haemoglobin level at 24 to 48 hours and at 40 to 45 days after delivery, blood transfusion, curettage, infection, and days of hospital stay.
Results Rates of subsequent manual removal were similar: intra-umbilical vein injection of saline solution plus oxytocin (58%; RR 0.92; 95% CI 0.73–1.15), or saline alone (63%; RR 1.00; 95% CI 0.80–1.24), compared with expectant management (63%). There were also no detectable effects of the active managements on any of the secondary measures of outcome.
Conclusions Based on evidence available from randomised controlled trials, including this trial, it is unlikely that intra-umbilical injection with or without oxytocin, is clinically useful. We recommend that this intervention should not be used in third stage management of labour.     

Intravenous nitroglycerin for controlled cord traction in the management of retained placenta

Objective

To determine the effect of 200 μg of intravenous nitroglycerin in the release of retained placenta by controlled cord traction.

Methods

In this randomized controlled study, 40 women with a placenta retained for 30 minutes received intravenously 200 μg of nitroglycerin or a normal saline solution before umbilical cord traction was initiated. The rates of successful removal of the retained placenta in the study (n = 20) and control (n = 20) groups were compared, as were blood pressure, pulse rate, blood loss, and adverse effects.

Results

The placenta was released in only 15% and 20% of the participants in the study and control group, respectively. The remainder of the participants required general anesthesia and manual removal of the retained placenta regardless of group assignation. Blood pressure fell in significantly more women in the study group, but there were no differences in estimated blood loss or minor adverse effects.

Conclusion

Intravenously administered nitroglycerin did not facilitate the release of retained placenta by umbilical cord traction. However, cord traction may be performed longer than 30 minutes to attempt releasing the placenta before operative manual removal is initiated.     

Reoccurrence of retained placenta at a subsequent delivery: an observational study

Objective: To test the generalizability of previously reported increased risk of reoccurrence of retained placenta in yet another setting.

Methods: In this observational retrospective study we longitudinally followed women who had a vaginal delivery complicated by a partial or complete retained placenta at Edith Wolfson Medical Center between 1 January 2009 and 31 December 2012. The study group included parturient women who had a partial or complete retained placenta after a vaginal delivery (n?=?90). The control group included parturient women who did not have a partial or complete retained placenta after a vaginal delivery from the same time period using the same inclusion criteria (n?=?90).

Results: Retained partial or complete placenta at a previous delivery was found to be an independent risk factor for retained partial or complete placenta in a subsequent delivery (adjusted OR 9.8, 95%CI 1.2 to 80.6, p?=?0.032) and for retained partial or complete placenta and/or postpartum hemorrhage in a subsequent delivery (adjusted OR 14.1, 95% CI 1.7 to 111.9, p?=?0.012), after controlling for gestational age and induction of labor at previous delivery.

Conclusion: Retained partial or complete placenta at an index delivery increases the risk of reoccurrence of retained partial or complete placenta in a subsequent delivery.     

Aetiological factors in placenta praevia a case controlled study

Summary. The obstetric and gynaecological histories of 80 women with proven placenta praevia have been reviewed together with case controls matched for age and parity. There was a significant relation between placenta praevia and previous caesarean section (P<0·05), dilatation and curettage (P相似文献   

Treatment of a retained placenta with intraumbilical oxytocin injection

The aim of the study was to assess the effect of intraumbilical administration of oxytocin in the management of retained placenta. This prospective double-blinded clinical study included 31 mothers with retained placenta. The women were divided into three groups: group 1 (n = 19) was given 20 IU syntocinon in 20 ml 0.9% NaCl saline intraumbilically into the vein (IUV); group 2 (n = 8) received 20 ml 0.9% NaCl saline; and group 3 (n = 4) received 0.2 mg ergometrine IUV in 20 ml 0.9% NaCl saline. Intraumbilical injection was used 30-45 min after delivery, and the distal cord segment was clamped to the umbilical vein.--In group 1, placental expulsion within 60 min of IUV oxytocin injection occurred in 13 (68.4%) women; in group 2, placental expulsion was recorded in one (12.5%) woman, whereas no placental expulsion occurred in group 3 women (p < 0.001). Complications in terms of major hemorrhage were not observed in group 1, whereas a hemorrhage of > 500 ml was recorded in one group 2 and 3 woman each. Febrility developed in one woman, and abdominal pain in two women from each group. Manual lysis of the placenta was performed in seven group 1, seven group 2, and all four group 3 women. IUV oxytocin injection provides a useful and inexpensive non-surgical, non-aggressive, cheap and pharmacological method which should be included in the treatment protocol for retained placenta before turning to the procedure of manual lysis of the placenta.     

A randomized controlled trial on the value of misoprostol for the treatment of retained placenta in a low-resource setting

Objective

To evaluate the efficacy and safety of misoprostol among patients with retained placenta in a low-resource setting.

Methods

A prospective, multicenter, randomized, double-blind, placebo-controlled trial was carried out in Tanzania between April 2008 and November 2011. It included patients who delivered at a gestational age of 28 weeks or more and had blood loss of 750 mL or less at 30 minutes after delivery. Sublingual misoprostol (800 μg) was compared with placebo as the primary treatment. Power analysis showed that 117 patients would be required to observe a reduction of 40% in the incidence of manual removal of the placenta (MRP; P = 0.05, 80% power), the primary outcome. The secondary outcomes were blood loss and number of blood transfusions.

Results

Interim analysis after recruitment of 95 patients showed that incidence of MRP, total blood loss, and incidence of blood transfusions were similar in the misoprostol (MRP, 40%; blood loss, 803 mL; blood transfusion, 15%) and placebo (MRP, 33%, blood loss 787 mL, blood transfusion, 23%) groups. The trial was stopped because continuation would not alter the interim conclusion that misoprostol was ineffective.

Conclusion

Treatment with misoprostol was found to have no clinically significant beneficial effect among women with retained placenta.Clinical Trial Registration: Current Controlled Trials ISRCTN16104753     

Bovine retained placenta: hormonal concentrations in fetal and maternal placenta

The aim of this study was to evaluate the relationship between the occurrence of retention of the fetal membranes (RFM) and the hormonal concentrations of progesterone, estradiol-17beta, prostaglandin E(2) (PGE(2)), prostaglandin F(2alpha) (PGF(2alpha)), oxytocin (OT), oxytocin receptor (OT-R), endothelin-1 and angiotensin II (Ang II) in the placental tissues of cattle. Parturition was induced in nine Holstein cows by a single injection of PGF(2alpha) on Day 274 of gestation. Six out of nine cows in the induced group did not release the fetal membranes within 12 h after parturition and served as the RFM group, and the remaining three cows in that group, which released their fetal membranes within 12 h, served as the non-RFM group. Five other cows calved spontaneously and served as controls. The placental tissues were collected immediately (0 h) and at 6 h after parturition. The hormonal concentrations were measured by enzyme immunoassay in maternal and fetal placental tissues from RFM, non-RFM and control cows. There were no differences in P4 and E2 concentrations among the RFM, non-RFM and control groups. The mean PGF(2alpha) concentration of the RFM group was lower than those of the non-RFM and control groups in the maternal part of the placenta. In maternal tissues, the OT and OT-R concentrations in the RFM group were lower than those at 0 and 6 h after parturition in the non-RFM group. Additionally, the Ang II concentration of the RFM group in both the maternal and fetal parts of placental tissues tended to be higher than those of the other groups. In conclusion, the present results suggest that ET-1 and Ang II may play differential tissue-specific roles in the placental unit that may amplify the local endocrinological cascade involving OT, OT-R and PGF(2alpha) interactions which are necessary for normal placental separation in the cow.     

Aetiological factors in placenta praevia--a case controlled study

The obstetric and gynaecological histories of 80 women with proven placenta praevia have been reviewed together with case controls matched for age and parity. There was a significant relation between placenta praevia and previous caesarean section (P less than 0.05), dilatation and curettage (P less than 0.01), spontaneous abortion (P less than 0.05) and evacuation of retained products of conception (P less than 0.05). Repeated uterine instrumentation was associated with increased risk of placenta praevia (P less than 0.001). We were unable to show any influence of previous termination of pregnancy. These findings are consistent with the hypothesis that endometrial/myometrium damage is a significant aetiological factor in low placental implantation.     

The Release Trial: a randomised controlled trial of umbilical vein oxytocin versus placebo for the treatment of retained placenta

Hypothesis   Intraumbilical injection of oxytocin reduces the incidence of manual removal compared with placebo in the treatment of retained placenta.
Entry criteria   The women recruited will be stable haemodynamically, not bleeding vaginally, over 34 weeks of gestation and with a retained placenta for at least 30 minutes.
Treatment arms   Oxytocin (50 IU) or sterile water (in identical vials) in 25 mL saline injected through an intraumbilical venous catheter.
Sample size   Five hundred seventy-two women.
Primary endpoint   Need for manual removal of placenta.
Centres   Initially, there will be two study sites in the UK (Liverpool and Sheffield) and five in Uganda (Mulago, Nsambia, Mengo, Rubaga and Arua).
Funding   World Health Organization and WellBeing of Women.     

Macroscopic and histological characteristics of retained placenta: A prospectively collected case-control study

IntroductionRetained placenta is a potentially fatal obstetric disorder due to postpartum hemorrhage, its pathophysiology is however unknown. We aimed to assess if retained placenta was associated with increased macroscopic and histological signs of placental maternal underperfusion, a pattern otherwise seen in preeclampsia and other disorders of defective placentation.MethodsThis was a case-control study of retained (n = 49) and non-retained (n = 47) placentas, collected from full-term singleton and otherwise healthy pregnancies, carried out at a tertiary level obstetric department. Macroscopic and histological analysis was performed. Signs of maternal placental underperfusion and signs of placental inflammation, fetal vascular thrombo-occlusive disease and increased placental attachment were recorded in a primary and secondary analysis respectively. Variables were compared groupwise using unconditional logistic regression or comparison of median or mean values.ResultsCompared to non-retained placentas retained placentas had a significantly smaller surface area (p = 0.05), were more oblong in shape (OR 5.24 95% CI:1.34–20.21) and showed overall more signs of maternal underperfusion (OR 2.52 95% CI: 1.07–5.87). There was no significant difference in signs of placental inflammation, fetal vascular thrombo-occlusive disease or placenta accreta but basal plate myometrial fibers were more common among retained placentas.ConclusionIn regard to shape, surface area and histological signs of maternal placental underperfusion, retained placentas showed a histological pattern similar to that seen in preeclamptic placentas.     

Sublingual nitroglycerin for management of retained placenta.

OBJECTIVE: The aim of the study was to investigate the effect of sublingual nitroglycerin for management of retained placenta and to assess possible adverse effects of the treatment. METHOD: Twenty-four women were randomly selected to receive either 1 mg nitroglycerin or placebo tablets sublingually if intravenous oxytocin and controlled umbilical cord traction had failed to expel the placenta. Success rate for delivery of placenta, blood pressure, pulse rate, blood loss, and various side effects were examined. RESULT: All 12 women in the nitroglycerin group had successful delivery of placenta, while removal of placenta was successful in only one of the 12 women in the placebo group. No adverse effects of clinical importance were registered. CONCLUSION: Sublingual nitroglycerin for treatment of retained placenta seems to be effective without causing serious adverse effects. However, the definite clinical value needs to be evaluated in larger series of patients.