Oxytocin Administration after Vaginal Delivery – Effects and Side Effects, Impact on Breastfeeding

Introduction Postpartum haemorrhage (PPH) is the leading cause of maternal death worldwide and is defined as a blood loss of more than 500ml. Four categories of mechanisms are responsible for PPH: atony, trauma, retention of placental tissue and thrombin abnormalities. To prevent PPH, the use of uterotonic medication postpartum is recommended as a standard of care. In Switzerland, 5 IU Oxytocin (OXT) in a short infusion is used after vaginal birth. There is a concern that exogenous OXT during and after delivery, may interfere with endogenous OXT receptors and might increase risk for atony and have a negative effect on breastfeeding behaviour. As part of a quality control we evaluated the effects and side effects of routine OXT administration after vaginal birth. Primary endpoint was breastfeeding (B) behaviour: exclusive (EB), predominant (DB) or partial breastfeeding (PB) or secondary weaning (SW) 4 months after vaginal delivery. Secondary endpoints were cardiovascular parameters immediately after OXT application, blood loss and breastfeeding behaviour at hospital discharge and 6 weeks after delivery.

Methods and Material Data was prospectively collected between 06/2020–06/2021. We used an electronic questionnaire including the duration of OXT application during labour, key characteristics of mother and newborn, effects and side effects. Women received SMS six weeks and four months after delivery. Women were eligible to participate after vaginal delivery, at≥36 weeks of gestation, age≥18 years and with intention to breastfeed. For the data analysis, χ2-tests, t-test and variance analysis were performed.

Results Until June 2021, 162 out of 300 included patients have been fully analysed. Mean age was 32.8 y (min 18, max 43 y), 45% (n=73) were primiparae. 79% (n=128) women had a spontaneous, 21% (n=34) an assisted vaginal delivery. 65% (n=106) participants had an epidural or a combined spinal and epidural anaesthesia (EA, CSEA).

Abb. 1

Side effects of OXT short infusion and the blood loss after delivery are summarized in table 1.

Tab. 1

8.6% (n=14) had a blood loss greater than 500 ml. PPH was in 50% (n=7) due to tonus, in 28,6% (n=4) due to tissue and in 21.4% (n=3) due to trauma (see .

Four months after vaginal delivery 56% (n=91) were EB, 8% (n=13) were DB, 16% (n=26) PB and 29% (n=32) underwent SW. Analysis of breastfeeding behaviour considering possible confounding variables will be submitted at a later date, as the number of patients included is too low at this point.

Discussion The application of OXT as a short infusion is very well tolerated with very few cases of side effects.

In our collective, 8.6% had a PPH. Compared to other data women in our collective had slightly more often PPH and PPH was caused half by tonus and half by placental tissue and trauma. Analysis of PPH causes considering possible confounding variables like oxytocin administration during labour will be submitted when all patients have been included.

Publication History

Article published online:
26 November 2021