Is the increase in postpartum hemorrhage after vaginal birth because of altered clinical practice?: A register‐based cohort study

Abstract

Background To identify risk factors for severe postpartum hemorrhage (PPH) ≥1000 ml in women giving birth vaginally. Method A register‐based cohort study including women with singleton pregnancies giving birth vaginally at term to a live‐born child at Aarhus University Hospital, Denmark, from January 1, 2004, to December 31, 2012. Logistic multivariable regression was used to analyze data. Results In 31 837 births, 1832 women (5.7%) experienced severe PPH. Maternal age, smoking during pregnancy, and prepregnancy body mass index did not increase the risk of severe PPH. However, nulliparous and multiparous women with a previous cesarean birth had an increased risk of severe PPH. Antepartum and intrapartum risk factors for severe PPH included gestational age >40 weeks, induction of labor, augmentation of labor, irregular fetal position, instrumental birth, and birthweight >4000 g. In particular, the combination of induction and augmentation of labor doubled the risk of severe PPH. Among genital tract tears, vaginal tears >3 cm were associated with the highest risk of severe PPH. Conclusions Maternal characteristics did not increase the risk of severe PPH, except for nulliparous and multiparous women with a previous cesarean birth. Obstetric interventions such as induction of labor, augmentation of labor, and a birthweight higher than 4000 g increased the risk of severe PPH. Larger vaginal tears presented the highest risk of severe PPH. Clinical practice with rigorous indications for obstetric interventions and timely identification and management of genital tract tears may reduce risk of severe PPH.

Postpartum haemorrhage trends in Sweden using the Robson ten group classification system: a population‐based cohort study

“…37 There is clinical evidence supporting the hypothesis that labour augmentation with oxytocin increases the risk of PPH in vaginal delivery, especially when preceded by IOL. 38 Suggested biological mechanisms are that high doses of oxytocin induce a desensitisation of the myometrial receptors, limiting endogenous uterine contractions and thereby increasing the risk of atony. 39 Studies including information on augmentation with oxytocin, ideally with information on the timing of administration and dose, are required to adequately assess associations between IOL, oxytocin use and PPH rates.…”

“…Unexplained, increasing trends in PPH have raised concern about the contemporary rise in obstetric interventions and the use of augmentation of labour with oxytocin, now a standard part of obstetric care in high‐income countries 37 . There is clinical evidence supporting the hypothesis that labour augmentation with oxytocin increases the risk of PPH in vaginal delivery, especially when preceded by IOL 38 . Suggested biological mechanisms are that high doses of oxytocin induce a desensitisation of the myometrial receptors, limiting endogenous uterine contractions and thereby increasing the risk of atony 39 .…”

The Relationship Between Obstetric Factors and Postpartum Haemorrhage Maternal Deaths in Jember District

“…As genital tract tears have a strong association with postpartum haemorrhage, timely identification and management by the birth attendant may reduce the amount of postpartum haemorrhage. Restricted use of episiotomy only with foetal indication is recommended, and slowing down the birth of the infant's head by assisting the parturient in breathing the baby´s head out between contractions or at the end of a contraction to avoid sphincter tears (Graugaard & Maimburg, 2021). The differences of the results in this study suspected due to the lack of research samples and the presence of other concomitant factors that require further research.…”

Incidence and risk factors for postpartum hemorrhage after vaginal delivery: A systematic review and meta‐analysis

“…6,[12][13][14] Being a teenage mother was reported as a protective factor, whereas another study did not agree with this finding. 13,15 Thus, it is necessary to understand the combination of risk factors by analyzing their relationships.…”

“…15,37 In addition, both induction and augmentation implemented during labor were reported at the highest risk of PPH. 13 Thus, in the future it is necessary to distinguish augmentation from induction as an independent risk factor. Cervical ripening and magnesium sulfate were added as risk factors related to vaginal delivery, which was seldom mentioned previously.…”