The mean cumulative dose of oxytocin administrated to women in our study was 3.9 µg following augmentation and 7.3 µg following induction of labour and the total amount of oxytocin was 17.5 µg for induction of labour and 14.8 µg for augmentation of labour. Roloff et al. obtained similar results in stimulated labour. The mean cumulative oxytocin dose was 2.3 U (3.9 µg). Selin et al. (2019) reported the amount administrated to women from begining of labour until delivery in low and high-dose oxytocin augmentation schemes . In low-dose regimens, women received 5.7 µg and while women in high-dose regimens received 7.9 µg , higher than the total amount found in our study. In studies assessing the relationship between oxytocin and BMI (Body mass index). The amount supplied from beginning of labour until delivery depending on BMI was 3.0-4.7 µg , 4.3-8.4 µg , 1.7-5.0 µg . Similar to our findings, Frey et al. (2015) found that induction was associated with higher maximum oxytocin doses . The fact that higher amounts of oxytocin were administrated to women following induction of labour is understandable, given that the infusion is likely to be continued for a more extended period.
Furthermore, there was a correlation between the mean cumulative dose of oxytocin infused, parity and duration of pregnancy. Multiparous women, on average, received lower the mean cumulative dose of oxytocin compared to nulliparous women. A longer duration of pregnancy was associated with a smaller amount of oxytocin being administered, i.e., women whose labours were induced at 40 weeks’ gestation, on average, received less oxytocin than women whose labours were induced at 39 weeks’ gestation. Similar correlations between parity were reported by Oscarssona et al. (2006). Multiparous women were less likely than nulliparous women to receive intrapartum oxytocin .
We also found a correlation between the mean cumulative dose of oxytocin administrated during labour and the use of epidural anaesthesia. Other studies have reported similar findings, both in terms of more frequent use of oxytocin administration after the epidural anaesthesia commenced [24,25] and in the more frequent use of epidural anaesthesia following oxytocin augmentation of labour. [26,27]. This may be explained, in part, by the more painful nature of oxytocin-stimulated contractions and restrictions in movement that many women face when continuous electronic fetal monitoring is required during labour induction or augmentation .
Although some studies have reported negative associations between intrapartum oxytocin administration and neonatal outcomes [23,29], we did not find any correlation between the the mean cumulative dose of oxytocin administrated Apgar scores and neonatal weight. However, using a more sensitive indicator of neonatal wellbeing, such as pH values in neonates, may lead to different results.
In our study, 84% of women birthed vaginally following labour augmentation, similar to the proportion of 87% found in a Danish study  but considerable higher than the 51% reported in Bugg et al.’s (2005) study with nulliparous women .
We did not find any correlation between the mean cumulative dose of oxytocin administrated to women before birth and the mode of delivery. In other words, women who received large amounts of oxytocin during labour were as likely as women who received small quantities to have an emergency CS. Similar findings were reported in studies comparing the high, and low-dose augmentation, where the higher doses of oxytocin administrated did not lower the risk of CS . A systematic review concluded that early administration of oxytocin did not affect the mode of birth . However, some studies have demonstrated a correlation between oxytocin administration and mode of delivery, including a lower risk of CS when compared to expectant management  but overall higher risk of intrapartum interventions [23,26,30]. Systematic reviews show that high-dose inductions and high-dose stimulations did not affect cesarean section rates. ,  We were unable to find any other study reporting on the correlation between the cumulative dose of oxytocin administered and mode of birth.
Ours findings show that the majority of hospitals in Warsaw did not have written protocols on intrapartum oxytocin administration for induction or augmentation of labour. Even in units where protocols were available and compliant with the national guidelines, the actual administration of oxytocin did not follow the recommended regimen in 94 % of labours.
While one study conducted in Germany found that 69% of participating units had protocols on oxytocin administration , they did not explore actual adherence to the protocol. In a study by Jackson establishing of a collaboration to build a consensus-driven, evidence-based approach to the use of oxytocin resulted within seven years in accordance with the guidelines in 73% to 100% . Studies show that the use of oxytocin in accordance with guidelines was associated with several significant clinical outcomes, including a decrease in cesarean births for fetal distress based on electronic fetal monitoring, decreases in length of first stage labour, and decreases in maximum dose of oxytocin. 
With few exceptions, the oxytocin infusion was continued in all the observed labours, despite the national guidelines, and information in Summary of Product Characteristics for oxytocin, stating that the infusion may be discontinued when labour becomes established, i.e., when cervical dilatation reaches 5 cm. In the light of the latest reports that show the benefit of discontinuing the infusion once established labour is achieved [34,35], observed practices require further analysis. Since too few women in our test group had oxytocin disconnected after reaching active labor, we could not compare this group with the rest. In Poland, we also do not have data on the percentage of cesarean sections in the group of women who received oxytocin during delivery, but only data on the overall percentage of cesarean sections.
The guidelines for the supply of oxytocin proposed by PSOGO do not apply to particular situations such as twin pregnancies, pregnancies with previous caesarean section, pregnancies in obese women. They also lack information on the dose of oxytocin that should be set after disruption of infusion for the time epidural anaesthesia provision.
Even assuming that there were situations in our study group that required non-standard behaviour, it seems unlikely that this would apply to over 90% of those surveyed.
Jackson et al. showed that the lack of oxytocin protocols was primarily due to insufficient consensus between those taking care of the mother (midwives and doctors), between providers and the relevant literature regarding specific, restrictive dosing of oxytocin. When midwives and doctors work together to write a guideline, it has a higher likelihood of being successfully followed . This was not our case, because national guidelines for oxytocin administration in Poland were formed by a group of expert obstetricians.
Typically, deviations from the protocol for stimulation have been associated with increasing time interval to dose escalation. This may be due to the burden being placed on staff when caring for several labouring women at a time and the inability to increase the dose at an exact interval. Investigating the cause of this condition, however, requires detailed research.
The Jackson study found that increasing compliance was associated with a statistically significant reduction in the amount of oxytocin used during labour and a reduction in the time between initiating oxytocin administration and the birth of the child .
The two maternity units selected for this study, despite having similar protocols on oxytocin administration, differed considerably in the rates of labour induction and augmentation, as well as the rates of vaginal births after labour induction. Similar discrepancies among units were reported in studies from Sweden and the UK, suggesting that care offered in different units is based on clinicians’ attitudes and preferences rather than on scientific research [23,27]. As stated previously, the oxytocin administration regimens were not followed in 510 (93.6%) of the labours observed during our study. Although there is no scientific consensus on the optimal oxytocin administration dose or regimen, clinicians should follow their unit’s guidelines unless exceptional circumstances are present.
One of the limitations of our study was the inability to access and analyse data from all women undergoing induction or augmentation of labour. Analysis of data from all women may have resulted in different outcomes.
We conducted the study in tertiary-level urban units providing specialist care to women who may have had complicated medical and obstetric history. Recruitment bias may have affected the rates of therapeutic interventions, including induction and augmentation rates, and it would be beneficial to conduct a similar study in units catering mostly for healthy women.