Uterine atony

Abstract

Purpose of reviewPostpartum hemorrhage (PPH) is the leading preventable cause of maternal morbidity and mortality worldwide. Uterine atony is identified as the underlying etiology in up to 80% of PPH. This serves as a contemporary review of the epidemiology, risk factors, pathophysiology, and treatment of uterine atony.Recent findingsRates of postpartum hemorrhage continue to rise worldwide with the largest fraction attributed to uterine atony. A simple 0–10 numerical rating score for uterine tone was recently validated for use during cesarean delivery and may allow for more standardized assessment in clinical and research settings. The optimal prophylactic dose of oxytocin differs depending on the patient population, but less than 5 units and as low as a fraction of one unit is needed for PPH prevention, with an increased requirements within that range for cesarean birth, those on magnesium, and advanced maternal age. Carbetocin is an appropriate alternative to oxytocin. Misoprostol shows limited to no efficacy for uterine atony in recent studies. Several uncontrolled case studies demonstrate novel mechanical and surgical interventions for treating uterine atony.SummaryThere is a critical, unmet need for contemporary, controlled studies to address the increasing threat of atonic PPH.

Postpartum hemorrhage in electronic health records: risk factors at admission and in-hospital occurrence

“…PPH is one of the commonest causes of preventable pregnancy-related death, causing 25% of maternal deaths worldwide. (13)(14)(15) But the prevalence varies according to the country analyzed, considering that successive improvements in maternity care during the 20th century have led to an impressive decline in the overall maternal mortality in high-income countries. In low income countries, PPH is still a challenge to be overcome.…”

Comparison of European recommendations about patient blood management in postpartum haemorrhage

“…[20][21][22][23] In obstetrics, with a PPH risk inherent to pregnancy and partum, PBM is particularly relevant. The incidence of maternal deaths is obviously higher in low-income countries due to limited resources, but it is also rising in high-income countries, 24 partially due to poor resuscitation management of patients with PPH, 25,26 atonic bleeding rise, 27 use of oxytocin for induction or augmentation of labour, 28 and caesarean surgeries "by choice." 29 PBM is probably more challenging in obstetrics than in other specialties, in part due to the lack of large well-designed clinical studies in the field, the still valid but wrong consideration of blood transfusions as the first line treatment to correct low haemoglobin values, and the hemodynamic changes that women experience during pregnancy.…”

“…In obstetrics, with a PPH risk inherent to pregnancy and partum, PBM is particularly relevant. The incidence of maternal deaths is obviously higher in low‐income countries due to limited resources, but it is also rising in high‐income countries, 24 partially due to poor resuscitation management of patients with PPH, 25,26 atonic bleeding rise, 27 use of oxytocin for induction or augmentation of labour, 28 and caesarean surgeries “by choice.” 29 …”

Tranexamic acid versus oxytocin for primary postpartum Haemorrhage in the out‐of‐hospital setting: A systematic review with implications for rural practice

“…Oxytocin is a nonapeptide hormone that serves as an agonist to oxytocin receptors throughout the human body. In a PPH, oxytocin stimulates the contractions of the myometrium to mechanically compress spiral arteries that become disrupted from the delivery of the placenta 5,6 . Although oxytocin is accepted as the preferred uterotonic in managing PPH, oxytocin must be stored at 2–8 degrees Celsius to maintain its effectiveness 7 .…”