Postpartum intrauterine pressure studies of the uterotonic effect of oral misoprostol and intramuscular syntometrine

Uterine activity during the third stage of labor

INTRODUCTION

The purpose of this study was to evaluate the use of intrauterine pressure catheters (IUPCs) to measure uterine activity during the third stage of labor.

METHODS

The study was conducted in a tertiary-care center. All births were attended by certified nurse-midwives. Low-risk pregnant women at term gestation had intrauterine monitoring attempted during the third stage of labor. Data were analyzed using descriptive statistics and analysis of variance.

RESULTS

Of the 36 women in the study, 19 had clear contractions recorded, 4 had unclear contractions, and 13 had flat tracings. The IUPC was useful for measuring uterine activity in a small number of women during the third stage of labor. When measured, uterine contractions were variable in strength and frequency.

DISCUSSION

Intrauterine pressure catheters can be used as a measurement of uterine activity during the third stage of labor and should be considered for future research about third-stage physiology. Further work is needed to determine the best procedure for placement, and IUPC use before expulsion of the placenta will not be useful in all women. Effective measurement of uterine activity may guide future research on interventions to reduce the risk of postpartum hemorrhage.

[Misoprostol for treating postpartum hemorrhages]

Postpartum hemorrhage is defined by bleeding > 500 mL through the vagina. It is one of the obstetrical complications that obstetricians fear most. It is the leading cause of maternal mortality in the world, especially in developing countries. The reference treatments in France are parenteral oxytocin and sulprostone. Sulprostone involves sometimes fatal side effects, and must be administered only in appropriate health care facilities. It also has the major disadvantage of requiring refrigeration. Misoprostol has uterotonic properties that have led to its occasional off-label use in the treatment of postpartum hemorrhage, by rectal or sublingual administration, as an alternative to sulprostone. A careful review of the literature on this particular use of misoprostol is essential.

Does the route of administration of misoprostol make a difference? The uterotonic effect and side effects of misoprostol given by different routes after vaginal delivery

OBJECTIVE

To compare the postpartum uterotonic effect and side effects of misoprostol administered by different routes.

STUDY DESIGN

Fifty women were given misoprostol 400 microg either by the oral solution, oral tablet, rectal or vaginal route, or intramuscular syntometrine 1 ml after spontaneous vaginal delivery. Pre- and post-treatment uterine activity were measured with intrauterine pressure catheters.

RESULTS

Uterine activity produced by oral solution misoprostol 400 microg was significantly higher than that of oral tablet, rectal and vaginal misoprostol (P = 0.004, 0.002, respectively). Onset of action after oral solution misoprostol was faster than by the oral tablet (P = 0.01), rectal (P < 0.001) and vaginal (P< 0.001) routes. Shivering and pyrexia were most common with oral solution misoprostol. Maximum body temperature recorded was significantly higher with oral solution misoprostol than with oral tablet, rectal and vaginal misoprostol (P = 0.009, 0.001, respectively).

CONCLUSION

Different routes of administering misoprostol greatly influence the effects achieved. Oral solution misoprostol produces the fastest and strongest uterotonic effect, with the most side effects.

Misoprostol for treating postpartum haemorrhage: a randomized controlled trial [ISRCTN72263357]

BACKGROUND: Postpartum haemorrhage remains an important cause of maternal death despite treatment with conventional therapy. Uncontrolled studies and one randomised comparison with conventional oxytocics have reported dramatic effects with high-dose misoprostol, usually given rectally, for treatment of postpartum haemorrhage, but this has not been evaluated in a placebo-controlled trial. METHODS: The study was conducted at East London Hospital Complex, Tembisa and Chris Hani Baragwanath Hospitals, South Africa. Routine active management of the third stage of labour was practised. Women with more than usual postpartum bleeding thought to be related to inadequate uterine contraction were invited to participate, and to sign informed consent. All routine treatment was given from a special 'Postpartum Haemorrhage Trolley'. In addition, participants who consented were enrolled by drawing the next in a series of randomised treatment packs containing either misoprostol 5 x 200 microg or similar placebo, which were given 1 orally, 2 sublingually and 2 rectally. RESULTS: With misoprostol there was a trend to reduced blood loss >/=500 ml in 1 hour after enrolment measured in a flat plastic 'fracture bedpan', the primary outcome (6/117 vs 11/120, relative risk 0.56; 95% confidence interval 0.21 to 1.46). There was no difference in mean blood loss or haemoglobin level on day 1 after birth < 6 g/dl or blood transfusion. Side-effects were increased, namely shivering (63/116 vs 30/118; 2.14, 1.50 to 3.04) and pyrexia > 38.5 degrees C (11/114 vs 2/118; 5.69, 1.29 to 25). In the misoprostol group 3 women underwent hysterectomy of whom 1 died, and there were 2 further maternal deaths. CONCLUSIONS: Because of a lower than expected incidence of the primary outcome in the placebo group, the study was underpowered. We could not confirm the dramatic effect of misoprostol reported in several unblinded studies, but the results do not exclude a clinically important effect. Larger studies are needed to assess substantive outcomes and risks before misoprostol enters routine use.

Prostaglandins in the prevention and management of postpartum haemorrhage

Myometrial contractility is integral to the delivery of the placenta and the arrest of potential subsequent haemorrhage. The details of this physiological process are patchy but it is clear that there is an important hormonal contribution. Oxytocin, with or without ergometrine, has thus been widely used with a recognized beneficial treatment effect. This practice, however, was never universal. The injectable nature of these agents restricted their wider use, even in societies with average medical services. The availability of the prostaglandin analogue misoprostol has renewed interest in the third stage of labour, has taken its pharmacological management to new frontiers, and has expanded the therapeutic options for the management of postpartum haemorrhage.

Post-partum haemorrhage: definitions, medical and surgical management. A time for change

Any woman who gives birth can have post-partum haemorrhage which may threaten her life. PPH is one of the leading causes of maternal mortality and an important cause for serious morbidity in the developing and developed world. We are at the threshold of major developments in its prevention and treatment due to changing ideas about its definition and medical and surgical management. The implementation of these changes is an essential part of a wider commitment towards saving mothers from complications of childbirth.