Prostaglandins in the prevention and management of postpartum haemorrhage

Maternal plasma cytokines and the subsequent risk of uterine atony and postpartum hemorrhage

OBJECTIVES

To determine whether the maternal plasma concentrations of cytokines are higher in pregnant women with postpartum hemorrhage (PPH) compared to pregnant women without PPH.

METHODS

A retrospective case-control study included 36 women with PPH and 72 matched controls. Cases and controls were matched for gestational age at delivery, labor status, delivery route, parity, and year of sample collection. Maternal plasma samples were collected up to 3 days prior to delivery. Comparison of the plasma concentrations of 29 cytokines was performed by using linear mixed-effects models and included adjustment for covariates and multiple testing. A false discovery rate adjusted p-value <0.1 was used to infer significance. Random forest models with evaluation by leave-one-out and 9-fold cross-validation were used to assess the combined value of the proteins in predicting PPH.

RESULTS

Concentrations of interleukin (IL)-16, IL-6, IL-12/IL-23p40, monocyte chemotactic protein 1 (MCP-1), and IL-1β were significantly higher in PPH than in the control group. This difference remained significant after adjustment for maternal age, clinical chorioamnionitis, and preeclampsia. Multi-protein random forest proteomics models had moderate cross-validated accuracy for prediction of PPH [area under the ROC curve, 0.69 (0.58-0.81) by leave-one-out cross validation and 0.73 (0.65-0.81) by 9-fold cross-validation], and the inclusion of clinical and demographic information did not increase the prediction performance.

CONCLUSIONS

Pregnant women with severe PPH had higher median maternal plasma concentrations of IL-16, IL-6, IL-12/IL-23p40, MCP-1, and IL-1β than patients without PPH. These cytokines could serve as biomarkers or their pathways may be therapeutic targets.

Prostaglandins for Postpartum Hemorrhage: Pharmacology, Application, and Current Opinion

BACKGROUND

Postpartum hemorrhage (PPH) remains a common cause of maternal mortality worldwide. Medical intervention plays an important role in the prevention and treatment of PPH. Prostaglandins (PGs) are currently recommended as second-line uterotonics, which are applied in cases of persistent bleeding despite oxytocin treatment.

SUMMARY

PG agents that are constantly used in clinical practice include carboprost, sulprostone, and misoprostol, representing the analogs of PGF2α, PGE2, and PGE1, respectively. Injectable PGs, when used to treat PPH, are effective in reducing blood loss but probably induce cardiovascular or respiratory side effects. Misoprostol is characterized by oral administration, low cost, stability in storage, broad availability, and minimal side effects. It remains a treatment option for uterine atony in low-resource settings, but its effectiveness as a uterotonic for independent application may be limited. Key Messages: The present review article discusses the physiological roles of various natural PGs, evaluates the existing evidence of PG analogs in the prevention and treatment of PPH, and finally provides a reference to assist obstetricians in selecting appropriate uterotonics.

Prostaglandin D2 evokes potent uterine contraction via the F prostanoid receptor in postpartum rats

Prostaglandin (PG) D₂, a prostanoid known to have hypotensive effect, can evoke increased in vitro prepartum myometrial contraction resulting from up-regulation of the F prostanoid (FP) receptor. The present study further determined postpartum rat uterine responses to PGD₂ to evaluate the possibility of the prostanoid becoming a therapeutic for postpartum uterine atony, a major cause of postpartum hemorrhage that can lead to maternal morbidity. In vitro and in vivo postpartum uterine responses to PGD₂ were determined and compared to those of prepartum rats. Here we show that in postpartum myometrial strips PGD₂ did evoke a contraction sensitive to FP receptor antagonism. Interestingly, this response was not only to a greater extent than that of prepartum rats, but also comparable with the contraction obtained with PGF_2α, a therapeutic for postpartum uterine atony but contradicted in conditions including hypertension. Indeed, PGD₂ was also found to cause increases of basal uterine contraction under in vivo conditions. Western blots revealed that the expression of FP receptors in postpartum myometrium was higher than that of prepartum rats. Moreover, we noted that the amount of PGD₂ produced in postpartum uteri, although lower than that of prepartum rats, was increased compared to non-pregnant conditions. These results thus demonstrate that due to a further up-regulation or high expression of myometrial FP receptors, PGD₂ can evoke potent uterine contraction postpartum, and hence the prostanoid, which is naturally synthesized in uterine tissues, could be a potential therapeutic for postpartum uterine atony, especially in settings, such as hypertension.

Pathophysiology of heavy menstrual bleeding

Heavy menstrual bleeding (HMB) is a common gynecological complaint with multiple etiologies and diverse pathophysiological origins. This review discusses HMB with reference to the recently proposed PALM-COEIN classification system for abnormal uterine bleeding, initially describing the endometrial events in normal menstruation followed by discussion of the perturbations of normal endometrial shedding that can result in HMB. Our present understanding of the mechanisms of menstrual bleeding as well as many of the pathological aberrations of HMB is incomplete. Further research into the pathophysiology of HMB is urgently needed, as clear knowledge of the mechanisms of this disorder will provide new therapeutic targets to formulate more effective treatments.

CEU: Prevention and Treatment of Postpartum Hemorrhage: New Advances for Low-Resource Settings

Postpartum hemorrhage due to uterine atony is the primary direct cause of maternal mortality globally. Management strategies in developed countries involve crystalloid fluid replacement, blood transfusions, and surgery. These definitive therapies are often not accessible in developing countries. Long transports from home or primary health care facilities, a dearth of skilled providers, and lack of intravenous fluids and/or a safe blood supply often create long delays in instituting appropriate treatment. We review the evidence for active management of third-stage labor and for the use of specific uterotonics. New strategies to prevent and manage postpartum hemorrhage in developing countries, such as community-based use of misoprostol, oxytocin in the Uniject delivery system, the non-inflatable antishock garment to stabilize and resuscitate hypovolemic shock, and the balloon condom catheter to treat intractable uterine bleeding are reviewed. New directions for clinical and operations research are suggested.

Rectal Misoprostol Versus Oxytocin in the Management of the Third Stage of Labour

OBJECTIVE

To compare the effect of rectal misoprostol with intramuscular oxytocin in the routine management of the third stage in a rural developing country.

METHODS

A randomized controlled trial was performed at two district hospitals in Ghana, West Africa. Four hundred fifty women in advanced labour were enrolled. The only exclusion criterion was a known medical contraindication to prostaglandin administration. Women were randomized to receive rectal misoprostol 800 microg or intramuscular oxytocin 10 IU with delivery of the anterior shoulder. The main outcome measure was change in hemoglobin concentration from before to after delivery. Secondary outcomes included the need for additional uterotonics, estimated blood loss, transfusion, and medication side effects.

RESULTS

Demographic characteristics were similar in each treatment group. There was no significant difference between treatment groups in change in hemoglobin (misoprostol 1.19 g/dL and oxytocin 1.16 g/dL; relative difference 2.6%; 95% confidence intervals [CI]-16.8% to 19.4%; P = 0.80). The only significant secondary outcome was shivering, which was more common in the misoprostol group (misoprostol 7.5% vs. oxytocin 0.9%; relative risk 8.0; 95% CI 1.86-34.36; P = 0.001).

CONCLUSION

Rectal misoprostol 800 microg is as effective as 10 IU intramuscular oxytocin in minimizing blood loss in the third stage of labour. Rectal misoprostol has a lower incidence of side effects than the equivalent oral dose. This confirms the utility of misoprostol as a safe and effective uterotonic for use in the rural and remote areas of developing nations where other pharmacologic agents may be less feasible.

Misoprostol versus oxytocin for the reduction of postpartum blood loss

OBJECTIVE

To compare the effect of 400 mug of oral misoprostol with 5 U of intravenous oxytocin in the reduction of postpartum blood loss and prevention of postpartum hemorrhage.

METHODS

In a prospective, double-blind, randomized controlled trial conducted in a tertiary maternity hospital 622 women received either 400 mug of oral misoprostol or 5 U of intravenous oxytocin after delivery of the anterior shoulder or within 1 min of delivery. The primary outcome was a hematocrit drop of 10% or greater 24 h postpartum. The secondary outcomes were a hemoglobin drop of 30 mg/L or greater, the use of additional oxytocin, an estimated blood loss greater than 1000 mL, manual removal of the placenta, a blood transfusion, and shivering and fever (>or=38 degrees C) as adverse effects of misoprostol.

RESULTS

There was no difference between the 2 groups regarding the primary outcome (a >or=10% hematocrit drop occurred in 3.4% and 3.7% of the participants in the oxytocin and misoprostol groups, P=0.98). The rate of use of additional oxytocin was higher in the misoprostol group (51% versus 40.5%, P=0.01). Shivering was confined to the misoprostol group (6.8%), and fever occurred in 12.5% of the women in the misoprostol group and 0.3% of the women in the oxytocin group.

CONCLUSION

The routine use of 400 microg of oral misoprostol was no less effective than 5 U of intravenous oxytocin in reducing blood loss after delivery, as assessed by change in postpartum hematocrit. The adverse effects of misoprostol were mild and self-limiting.

Examining the evidence for The International Confederation of Midwives’ essential competencies for midwifery practice

OBJECTIVE

to present the evidence for inclusion of selected midwifery tasks (skills) as essential practice competencies for midwives throughout the world. The tasks addressed are those presented to the International Confederation of Midwives (ICM) Council of Delegates in 2002 for discussion and adoption, based on the fact that during field-testing, notable variance was encountered.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

evidence-based practice should be characterised by the use of best practices derived from rigorous research, combined with and balanced by client perspectives and the expert judgement based on the critical thinking of the clinician. Much of midwifery practice is considered an art based on common sense, tradition, and woman-centred approaches to caring, as most of the women who seek midwifery care are healthy and require a health-promotion model of care that may not easily lend itself to examination by scientists or clinicians. However, when intervention is indicated to save the lives of mother, baby, or both, those interventions must be based on the best available evidence from a variety of sources leading to the most effective choices for action. The ICM Essential Competencies for Midwifery Practice (2002) are based on evidence derived from a variety of quantitative and qualitative methodologies. Expert clinical consensus may serve as to the best form of evidence at certain points in the evolution of knowledge. Every midwife needs to understand where the gaps exist in supporting traditional practices that have yet to be fully examined in a scientific manner. In summary, a multi-matrix or triangulated approach may be most appropriate to the delineation of evidence underpinning best midwifery practice.