Transfers of Care between Healthcare Professionals in Obstetric Units of Different Sizes across Spain and in a Hospital in Ireland: The MidconBirth Study

International Journal of Environmental Research and Public Health Article Transfers of Care between Healthcare Professionals in Obstetric Units of Different Sizes across Spain and in a Hospital in Ireland: The MidconBirth Study Anna Martín-Arribas 1,2 , Rafael Vila-Candel 3,4,5,* , Rhona O’Connell 6, Martina Dillon 7, Inmaculada Vila-Bellido 8, M. Ángeles Beneyto 8, Inmaculada De Molina-Fernández 9, Nerea Rodríguez-Conesa 10, Cristina González-Blázquez 2and Ramón Escuriet 1,11 1 GHenderS Research Group, School of Health Sciences Blanquerna, Universitat Ramon Llull, Carrer Padilla 326, 08025 Barcelona, Spain; [email protected] (A.M.-A.); r[email protected] (R.E.) 2Faculty of Medicine, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo 4, 28029 Madrid, Spain; [email protected] 3La Ribera Hospital Health Department, Carretera Corbera km 1, 46600 Valencia, Spain 4Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO), 46020 Valencia, Spain 5Faculty of Nursing and Podiatry, Universitat de València, Jaume Roig, s/n, 46010 Valencia, Spain 6School of Nursing and Midwifery, University College Cork, T12 YN60 Cork, Ireland; r[email protected] 7Cork University Maternity Hospital, Wilton, T12 YE02 Cork, Ireland; [email protected] 8Verge dels Lliris Hospital, Poligon de Caramanxel s/n, 03804 Alcoi, Spain; [email protected] (I.V.-B.); [email protected] (M.Á.B.) 9Nursing Department, Universitat Rovira i Virgili, 43003 Tarragona, Spain; [email protected] 10 Rio Hortega Hospital, Calle Dulzaina, 2, 47012 Valladolid, Spain; [email protected] 11 Catalan Health Service, Government of Barcelona, 08028 Catalonia, Spain *Correspondence: [email protected] Received: 17 October 2020; Accepted: 11 November 2020; Published: 13 November 2020   Abstract: Background: In Europe, the majority of healthy women give birth at conventional obstetric units with the assistance of registered midwives. This study examines the relationships between the intrapartum transfer of care (TOC) from midwife to obstetrician-led maternity care, obstetric unit size (OUS) with different degrees of midwifery autonomy, intrapartum interventions and birth outcomes. Methods: A prospective, multicentre, cross-sectional study promoted by the COST Action IS1405 was carried out at eight public hospitals in Spain and Ireland between 2016–2019. The primary outcome was TOC. The secondary outcomes included type of onset of labour, oxytocin stimulation, epidural analgesia, type of birth, episiotomy/perineal injury, postpartum haemorrhage, early initiation of breastfeeding and early skin-to-skin contact. A logistic regression was performed to ascertain the effects of studied co-variables on the likelihood that participants had a TOC; Results: Out of a total of 2,126 low-risk women, those whose intrapartum care was initiated by a midwife (1772) were selected. There were statistically significant differences between TOC and OUS (S1 =29.0%, S2 =44.0%, S3 =52.9%, S4 =30.2%, p<0.001). Statistically differences between OUS and onset of labour, oxytocin stimulation, type of birth and episiotomy or perineal injury were observed (p=0.009, p<0.001, p<0.001, p<0.001 respectively); Conclusions: Findings suggest that the model of care and OUS have a significant effect on the prevalence of intrapartum TOC and the birth outcomes. Future research should examine how models of care differ as a function of the OUS in a hospital, as well as the cost-effectiveness for the health care system. Keywords: midwife-led care; obstetrician-led care; continuity of care; transfer of care; maternal outcomes; neonatal outcomes Int. J. Environ. Res. Public Health 2020,17, 8394; doi:10.3390/ijerph17228394 www.mdpi.com/journal/ijerph Int. J. Environ. Res. Public Health 2020,17, 8394 2 of 15 1. Background The past few years have witnessed the emergence of a worldwide debate about the care that healthy women receive when giving birth. This debate includes differing opinions as to the use of various technologies for normal or low-risk procedures [ 1 ], the concept of labour as a physiological process that is not to be understood in solely medical terms, and the growing role women themselves are taking in the decision-making processes affecting their care [ 2 ]. Additionally, the increase in the frequency of interventions carried out during labour, especially of caesarean sections, is a source of concern for a number of organization and for health care officials. In different European countries, the rates are about 25% to 35% [3,4]. The organizational structure of maternity services might have an influence on the health outcomes of women and new-borns [ 5 ]. The way these medical services are organized determines the level of continuity of care offered and the choice of which professionals provide what kinds of care throughout the process of pregnancy, labour and postpartum care. A number of studies have shown positive results when midwives are the primary providers of care throughout the process [6]. Maternity care in Europe is offered by organizations with a number of different kinds of structures, settings and locations [ 7 ]. The degree to which European health care systems offer coverage varies from country to country [ 8 ]. In some places, women are guaranteed coverage for the whole range options, whether women choose home births, birth centres, maternity units attended by midwives or conventional obstetric units. The size of maternity units also vary as does the degree of midwifery autonomy [ 6 ]. The most common model in European countries is that of providing care in conventional obstetrics units [ 9 ]. This translates into a situation in which most healthy women receive care in highly technological settings. Additionally, the frequency of intrapartum interventions varies greatly from place to place [10]. The quality of care provided to women during labour has been extensively studied by a number of researchers [ 11 ]. Nonetheless, most of the indicators used in these studies have been aimed at assessing the use of interventions and at seeking out results based on pathology (i.e., postpartum haemorrhages, perineal tears, etc.). The aim of the MidconBirth study is to offer a new perspective on this issue and to contribute to research on the assessment of the quality of care that women receive when in labour [ 9 ]. In most health care services, midwives are the primary providers of care throughout the process, but this is not always the case [ 6 ]. The roles of different care providers vary depending on how health services and medical teams are organized [ 12 ]. Most women who give birth are healthy or at least at low-risk during their pregnancies, and they tend to receive care from midwives who exercise complete autonomy from the onset of labour [ 13 ]. The transfer of care (TOC) during labour means that midwives are responsible for detecting any risk, problem or pathology requiring the intervention of another professional [ 11 ]. In some cases, however, midwives’ degree of autonomy is affected by the organizational structure of professional teams. In Spain, most women in labour receive care in obstetric units staffed by both obstetricians and midwives [ 14 ]. These units have all the necessary technology to provide care for women regardless of the level of risk present in the pregnancy. Care is provided by professional teams organized into hierarchical structures [ 7 ]. As a result, procedures are often determined by protocols, and professionals tend to work in accordance with a given centre’s organizational culture. In general, midwives tend to be responsible for women with low-risk pregnancies during labour [ 6 ]. The degree of autonomy exercised by these midwives varies from centre to centre [ 6 ]. Meanwhile, obstetricians act as consultants in these cases. In Ireland, intrapartum care for women with low-risk pregnancies is provided under the Mother and Infant Care Scheme [ 15 ], a program that promotes individualized care for low risk women in labour by midwives and under which obstetricians act only upon the request of these midwives. Studies have shown that midwife-led models are associated with both fewer medical interventions and increased satisfaction with the birthing experience [ 6 ]. However, a recent study on obstetric interventions in Spain suggests the need for further examination of factors associated with the organisation of childbirth services which are influencing these interventions [13]. Int. J. Environ. Res. Public Health 2020,17, 8394 3 of 15 This study examines the relationships between the intrapartum transfer of care from midwife to obstetrician-led maternity care and the obstetric unit size (OUS), intrapartum interventions and birth outcomes within two different countries with a different midwifery organisation of care. 2. Methods This article presents part of the results obtained within the MidconBirth study. This is a prospective, multicentre, cross-sectional study promoted by the COST Action IS1405 carried out in different hospitals in Spain and Ireland. The protocol can be accessed through the registry ISRCTN14062994 [ 9 ]. For the purposes of this study, we selected births attended to in obstetric units in three different regions that are representative for Spain in terms of sociodemographic and economical characteristics (Catalonia, C. Valenciana and Castilla y Le ó n), and another in Ireland. These include hospitals with low volumes of births (<600 births per year) or Unit Size 1 (S1), medium (from 601 to 1200 births) and high annual volumes of births (1201 to 2400 births) or Unit Size (S2) and Unit Size (S3) respectively, as well as births attended to by a continuity of care team in Ireland (Cork), a hospital with high annual volume of births (>2400 births) or Unit Size 4 (S4). Data were collected through an online platform in 2016–2019. The sample was limited to primiparous and multiparous women between 18 and 40 years of age with a singleton, cephalic presentation and uncomplicated pregnancy between 37 and 42 weeks of gestation. For this study, women with pregnancies classified as high or very high risk were excluded. The reference population was 5708 women. The sample size is calculated on the annual number of births of each participating centre or midwife. To calculate the sample size (95% level of confidence) it is assumed an unknown proportion of births attended by midwives for each estimated population (50%) in each setting, with a (+/ − ) 5% precision and a reposition proportion of 10%. A minimum estimated sample size was 365 women to achieve a representative sample for each hospital in Spain and for the caseload midwifery team in Ireland. Data collection was conducted consecutively during the specified period until the minimum number of cases needed was reached. The primary outcome was transfer of care (TOC). This happens when the professional who is looking after the woman at the start of her labour transfers the responsibility of care to another professional. The secondary outcomes included type of onset of labour (spontaneous or induced labour), oxytocin stimulation (use of oxytocin during the first or second stage of labour), epidural analgesia (use of epidural analgesia during the second or third stage of labour), type of birth (normal or dystocic), episiotomy/perineal injury (the use of episiotomy and/or presence or perineal damage), postpartum haemorrhage (more than 1000 mL of blood loss), early initiation of breastfeeding (within one hour from birth) and early skin-to-skin contact (contact between mother and new-born is started immediately after birth and/or uninterrupted during the first 30 min). Descriptive statistics were used to summarize the women’s characteristics. The statistical analysis was carried out using the SPSS program version 23.0 (IBM SPSS Statistics for Windows, Version 25.0, released 2018, IBM Corp., Armonk, NY, USA). Frequencies and percentages of the categories were calculated for all the variables. The standard deviation (SD) of the quantitative variables mean was calculated. The Chi-square test was used to analyse the statistical significance of the differences in the percentages of hospital groups between the variable categories; for risk factors for transfers of care, an odds ratio (OR) with a 95% CI, was calculated. A multivariate logistic regression models were performed to ascertain the effects of studied co-variables on the likelihood that participants had a TOC. These models were adjusted using a stepwise variable selection process based on a likelihood ratio (LR). Nagelkerke’s R 2 was used to estimate the coefficient of determination from 0 to 1. The significance level was set at p<0.05. Ethics Approval and Consent to Participate The MidconBirth study was approved by the ethics committee of the coordinating centre (Clinical Research Ethics Committee of Parc Salut Mar 2016/6785/I) ISRCTN registry 17,833,269 and later by the ethics committee of each participating centre (Clinical Research Ethics Committee of the Catalan Int. J. Environ. Res. Public Health 2020,17, 8394 4 of 15 Hospitals Union Foundation (CPMP/ICH/135/95), Clinical Research Ethics Committee of Rio Ortega Hospital (117/16), Clinical Research Ethics Committee (CREC) Cork Ref ECM4 (09/05/17), Human Ethics Committee at Hospital Universitario de La Ribera Research Ethics Committee and Research Commission and the Spanish Medicines and Medical Devices Agency approved the study (HULR15/12-01), Research Ethics Committee of Complejo Asistencial Universitario de Palencia (CIB-2017005) and Research Ethics Committee of Hospital Verge dels Lliris. Ethics committee approval was required for each participating hospital. Since this is an observational study in which data was anonymized, no consent was required from the women cared for in the participating centres. If a hospital required consent from the women under their care, written consent was obtained. Further information and documentation are available on request. 3. Results 3.1. Characteristics of the Sample The total sample analysed was made up of 2126 cases. In terms of the regional distribution, Cork (Ireland) collected data on 7.1% (150) of the cases, 44.7% (951) were in Catalonia, 48.2% (1025) in the regions of Valencia and Castilla y Le ó n (Spain). Regarding the obstetric unit size distribution, S1 represented 8.8% (187) of the cases, 51% (1086) were in S2, 33% (703) were in S3 and 7.1% (150) were in S4 (Figure 1). Int. J. Environ. Res. Public Health 2020, 16, x 4 of 16 Ethics Approval and Consent to Participate The MidconBirth study was approved by the ethics committee of the coordinating centre (Clinical Research Ethics Committee of Parc Salut Mar 2016/6785/I) ISRCTN registry 17,833,269 and later by the ethics committee of each participating centre (Clinical Research Ethics Committee of the Catalan Hospitals Union Foundation (CPMP/ICH/135/95), Clinical Research Ethics Committee of Rio Ortega Hospital (117/16), Clinical Research Ethics Committee (CREC) Cork Ref ECM4 (09/05/17), Human Ethics Committee at Hospital Universitario de La Ribera Research Ethics Committee and Research Commission and the Spanish Medicines and Medical Devices Agency approved the study (HULR15/12-01), Research Ethics Committee of Complejo Asistencial Universitario de Palencia (CIB2017005) and Research Ethics Committee of Hospital Verge dels Lliris. Ethics committee approval was required for each participating hospital. Since this is an observational study in which data was anonymized, no consent was required from the women cared for in the participating centres. If a hospital required consent from the women under their care, written consent was obtained. Further information and documentation are available on request. 3. Results 3.1. Characteristics of the Sample The total sample analysed was made up of 2126 cases. In terms of the regional distribution, Cork (Ireland) collected data on 7.1% (150) of the cases, 44.7% (951) were in Catalonia, 48.2% (1025) in the regions of Valencia and Castilla y León (Spain). Regarding the obstetric unit size distribution, S1 represented 8.8% (187) of the cases, 51% (1086) were in S2, 33% (703) were in S3 and 7.1% (150) were in S4 (Figure 1). Figure 1. Study flow chart. The average age of the women in the study was 31.7 ± 4.9 years. Broken down by country of origin, 70.2% (1490) of the women were from Spain, 11.8% (250) were from elsewhere in Europe, 7.3% Figure 1. Study flow chart. The average age of the women in the study was 31.7 ± 4.9 years. Broken down by country of origin, 70.2% (1490) of the women were from Spain, 11.8% (250) were from elsewhere in Europe, 7.3% (155) were from South or America, 8.1% (172) were from Africa, 2.0% (42) were from Asia, 0.5% (10) were from the Middle East, 0.2% (four) were from North America and for 0.1% (three) of the women this data was missing. 36.3% (772) of the women had attended university, 34.3% (729) had high school degrees, and 25.2% (535) had only completed primary school, while for 4.2% (90) of the women the level of Int. J. Environ. Res. Public Health 2020,17, 8394 5 of 15 education was unknown or could not be classified. 52.3% (1111/2126) were primiparous, while the average gestation period before labour was 39.0 ±3.0 weeks (range of 37–41). The clinical characteristics of women in every OUS group are shown in Table 1, which also displays the statistically significant differences between OUS, with the exception of the use of epidural anaesthesia (p=0.632). Table 1. Characteristics of the sample, by obstetric unit size (N=2126). Obstetric Unit Size S1 n=187 S2 n=1086 S3 n=703 S4 n=150 n%n%N%n% Total p* Onset of labour Spontaneous 163 87.2 745 68.6 492 70.0 127 84.6 1527 <0.001 Induced 23 12.3 331 30.5 181 25.7 22 14.7 557 C-section 1 0.5 10 0.9 30 4.3 1 0.7 42 Pharmacological stimulation of labour No 129 69.0 419 38.6 208 29.6 99 66.0 855 <0.001 Yes 58 31.0 667 61.4 495 70.4 51 34.0 1271 Epidural analgesia No 30 16.0 169 15.6 102 14.5 28 18.7 329 0.632 Yes 157 84.0 917 84.4 601 85.5 122 81.3 1797 Type of birth Normal 145 77.5 757 69.7 442 62.9 104 69.3 1448 <0.001 Dystocic 42 22.5 329 30.3 261 37.1 46 30.7 678 Weight of newborn (g) <2500 5 2.7 15 1.4 6 0.9 0 0.0 26 <0.001 2501–3000 34 18.2 227 20.9 142 20.2 10 6.7 413 3001–3500 84 44.9 505 46.5 302 43.0 52 34.7 943 3501–4000 49 26.2 284 26.2 212 30.2 53 35.3 598 >4001 15 8.0 55 5.1 41 5.8 35 23.3 146 Perineum No episiotomy or 1st or 2nd degree 111 59.4 555 51.1 398 56.6 100 66.7 1164 0.001 Presence of episiotomy or 3rd or 4th degree 76 40.6 531 48.9 305 43.4 50 33.3 962 Postpartum haemorrhage No 182 97.3 1064 98.0 676 96.2 139 92.7 2061 0.002 Yes 5 2.7 22 2.0 27 3.8 11 7.3 65 Early skin-to-skin contact Yes 180 96.3 959 88.3 646 91.9 141 94.0 1926 0.001 No 7 3.7 127 11.7 57 8.1 9 6.0 200 Early initiation of breastfeeding Yes 165 88.2 823 75.8 552 78.6 124 83.2 1664 0.001 No 22 11.8 263 24.2 150 21.4 25 16.8 460 Professional attending the onset of labour Midwife 181 96.8 901 83.0 546 77.7 149 99.3 1777 <0.001 Obstetrician 6 3.2 185 17.0 157 22.3 1 0.7 349 Professional attending the birth Midwife 132 70.6 677 62.3 324 46.1 104 69.3 1237 <0.001 Obstetrician 55 29.4 409 37.7 379 53.9 46 30.7 889 Birth attended by midwife from start to end Yes 132 70.6 603 55.5 317 45.1 104 69.3 1156 <0.001 No 55 29.4 483 44.5 386 54.9 46 30.7 970 * Chi-square test; S1 =Obstetric Unit Size 1 (<600 births per year); S2 =Obstetric Unit Size 2 (from 601 to 1200 births per year); S3 =Obstetric Unit Size 3 (1201 to 2400 births per year); S4 =Obstetric Unit Size 4 (>2400 births per year). Of women who had dystocic births, in S1 we observed that 12.3% (23) of women required emergency caesarean sections; in S2 the percentage was 12.6% (137); in S3 16.5% (116) and in S4 11.3% (17). The differences here were statistically significant (p<0.001). S1 displayed a lower percentage of Int. J. Environ. Res. Public Health 2020,17, 8394 6 of 15 transfer (29.4%), fewer cases of labour stimulated with oxytocin (31.0%) and fewer cases of induced labour (12.4%). Meanwhile, S1 displayed the highest percentages of normal births (77.5%), skin-to-skin contact between the mother and the new-born (96.3%), and early initiation of breastfeeding (88.2%). S2 showed the highest percentage of induced labour (30.8%), serious perineal injuries including episiotomies and thirdand fourth-degree perineal tears (48.9%), but this OUS showed the lowest percentage of postpartum haemorrhages (2.0%). S3 displayed the greatest percentage of transfer (54.9%), of labour stimulation with oxytocin (70.4%), of the use of epidural analgesics (85.5%) and of dystocic births (37.1%). S4 showed the lowest proportion of births with epidural analgesia (18.7%), was most likely to lack serious perineal injuries, characterized as cases where the perineum was intact or cases with second and third degree perineal tears (66.7%), and had the highest percentage of the start of labour attended by midwives (99.3%). However, this OUS also displayed the highest percentage of postpartum haemorrhages (7.3%). 3.2. Transfer Analysis We were interested in analysing the relationship between the TOC between the midwife and the obstetrician and the rest of the factors that influence a birth. For the purposes of this analysis, cases of elective caesarean sections (42) were excluded. Thus, the total number of cases analysed was 2084. Midwives attended the start of the deliveries in 85.1% (1773/2084), and they attended during the expulsive phases of the deliveries in 59.4% (1237/2084) of cases. Meanwhile, obstetricians attended the start of the deliveries in 14.9% (311/2084) of cases, and they attended the end of deliveries in 40.6% (847/2084) of cases. In 55.5% (1156/2084) of the deliveries, there was no TOC from the midwife to the obstetrician. In other words, in these cases midwives attended the whole labour and birth process. In terms of the distribution by OUS, the midwives in S1 were the least likely to transfer care (with 71.0% [132/186] attending to the labour and birth in its entirety), followed by those in S4 (69.8% [104/149]), S2 (56.0% [1076/673]) and, finally, S3 (47.1% [317/773]). We conducted an analysis of the differences in the labour and birth processes and the associated perinatal results in each OUS, examining them in terms of whether or not there was a TOC during the process. For the variables analysed, (type of start of labour, pharmacological stimulation of labour, use of epidural analgesics, type of birth and status of the perineum), statistically significant differences were found, both within each obstetric unit size and for the sample as a whole. It is true that the midwife might not be directly responsible for the decision to induce labour, as this represents a departure from a normal birth because the onset is not spontaneous. However, this process is often determined by protocol and characterized by a shared responsibility of the midwife and the team of obstetricians [7]. Our analysis of the factors associated with a greater likelihood of TOC and the risks associated with this practice is displayed in the 2 ×2 tables and the odds ratio calculations (Table 2). When there was no TOC, S4 recorded the highest proportion of spontaneous onset of labour [S4 93.3% (97/104), compared with S1 at 90.9% (120/132), S2 at 83.3% (502/603), and S3 at 83.0% (263/317)], and the differences found here were statistically significant (p<0.001). S3 showed the highest rate of induced births attended by midwives in which no TOC occurred [17.0% (54/317), while for S2 the figure was 16.7% (101/603), for S1 it was 9.1% (12/132), and for S4 it was 6.7% (7/104)]. The differences found were statistically significant (p<0.001). S4 displayed the lowest frequency of oxytocin use in deliveries when no TOC occurred [13.5% (14/104)]. Meanwhile, S3 registered the highest rate of pharmacological stimulation (55.5% [176/317]). Additionally, in S4 TOC was more likely when oxytocin was used, or labour was stimulated, increasing with respect to when labour was not stimulated (p<0.001). Int. J. Environ. Res. Public Health 2020,17, 8394 7 of 15 Table 2. Transfer of care distribution between different studied variables, and Odds Ratio and 95% confidence intervals (N=2084). Obstetric Unit Size S1 S2 S3 S4 Total Midwife Start to End p * Midwife Start to End p * Midwife Start to End p * Midwife Start to End p * Midwife Start to End p * Yes (132) No (54) Yes (603) No (473) Yes (317) No (356) Yes (104) No (45) Yes (1156) No (928) n% col n% col n% col n% col n% col n% col n% col n% col n% col n% col Onset of labour Spontaneous 120 90.9 43 79.6 0.048 502 83.3 243 51.4 <0.001 263 83 229 64.3 <0.001 97 93.3 30 66.7 <0.001 982 47.1 545 26.2 <0.001 Induced 12 9.1 11 20.4 101 16.7 230 48.6 54 17 127 35.7 7 6.7 15 33.3 174 8.3 383 18.4 Pharmacological stimulation None 107 81.1 21 38.9 <0.001 288 47.8 121 25.6 <0.001 141 44.5 65 18.3 <0.001 90 86.5 8 17.8 <0.001 626 0.3 215 10.3 <0.001 Yes 25 18.9 33 61.1 315 52.2 352 74.4 176 55.5 291 81.7 14 13.5 37 82.2 530 25.4 713 34.2 Epidural analgesia None 28 21.2 2 3.7 0.003 128 21.2 41 8.7 <0.001 79 24.9 23 6.5 <0.001 25 0.24 3 6.7 0.013 260 12.5 69 3.3 <0.001 Yes 104 78.8 52 96.3 475 78.8 432 91.3 238 75.1 333 93.5 79 0.76 42 93.3 896 0.43 859 41.2 Type of birth Normal 132 100.0 13 24.1 <0.001 603 1 154 32.6 <0.001 317 1 125 35.1 <0.001 104 1 0 0 <0.001 1156 55.5 292 0.14 <0.001 Dystocic 0 0.0 41 75.9 0 0 319 67.4 0 0 231 64.9 0 0 45 1 0 0 636 30.5 Episiotomy None vs. I-II grade 100 75.8 10 18.5 <0.001 436 72.3 118 24.9 <0.001 236 74.4 160 44.9 <0.001 98 94.2 2 4.4 <0.001 870 41.7 290 13.9 <0.001 Yes vs. III-IV grade 32 24.2 44 81.5 167 27.7 355 75.1 81 25.6 196 55.1 6 5.8 43 95.6 286 13.7 638 30.6 Postpartum haemorrhage None 129 97.7 52 96.3 0.584 595 98.7 459 0.97 0.06 308 97.2 341 95.8 0.337 98 94.2 40 88.9 0.252 1130 54.2 892 42.8 0.01 Yes 3 2.3 2 3.7 8 1.3 14 0.03 9 2.8 15 4.2 6 5.8 5 11.1 26 1.2 36 1.7 Early skin-to-skin contact Yes 128 97.0 51 94.4 0.411 528 87.6 424 89.6 0.289 297 93.7 322 90.4 0.122 98 94.2 42 93.3 0.833 1051 50.4 839 40.3 0.239 None 4 3.0 3 5.6 75 12.4 49 10.4 20 6.3 34 9.6 6 5.8 3 6.7 105 0.05 89 4.3 Early initiation of breastfeeding Yes 118 89.4 46 85.2 0.42 449 74.5 367 77.6 0.234 242 76.6 289 81.2 0.144 85 82.5 39 86.7 0.529 894 42.9 741 35.6 0.047 None 14 10.6 8 14.8 154 25.5 106 22.4 74 23.4 67 18.8 18 17.5 6 13.3 260 12.5 187 0.09 p*: Chi-squared test; S1 =Obstetric Unit Size 1 (<600 births per year); S2 =Obstetric Unit Size 2 (from 601 to 1200 births per year); S3 =Obstetric Unit Size 3 (1201 to 2400 births per year); S4 =Obstetric Unit Size 4 (>2400 births per year); CI, Confidence Interval; ns, non-significant value >0.05. Int. J. Environ. Res. Public Health 2020,17, 8394 8 of 15 In cases where there was no TOC, S3 registered the lowest rate of use of epidural analgesics [75.1% (238/317)], while S1 and S2 displayed the greatest tendency to administer them (78.8% ([104/132] and 78.8% [475/603], respectively). In S1, the risk of TOC was seven times higher when epidural analgesics were administered than when they were not (p=0.003), with the rate reaching 96.3% (52/54) in these cases. The lowest prevalence of TOC associated with the use of epidural analgesics was found in S2 (p<0.001), where the figure was 91.3% (432/473). In terms of the type of birth, all the spontaneous vaginal deliveries (SVD) in S4 (104/104) were attended by midwives, and therefore, there was no TOC. In contrast, none of the S4 births in which TOC occurred were SVD (0/45). Meanwhile, in S3, 35.1% (125/356) of the deliveries that featured transfers of responsibilities were SVD and attended by obstetricians. The risk of TOC associated with labour ending in dystocia was the highest in S1 (S1, p<0.001; S2, p<0.001; S3, p<0.001). With respect to the condition of the perineum when no TOC occurred, the S4 registered the highest number of cases with intact perineum or 1st or 2nd degree perineal tears [94.2% (98/104)], compared with the figure of 72.3% (436/603) for S2. In contrast, when TOC occurred, the highest rate of intact perineum or 1st or 2nd degree perineal tears was found in S3 [44.9% (160/356)], while S4 displayed the lowest rate [4.4% (2/45)]. Meanwhile, these episiotomies or thirdor fourth-degree tears were present in 95.6% (43/45) of the cases in S4 when TOC was performed. The lowest rate in this regard was found in S3 [55.1% (196/356]. Thus, when TOC occurs, the risk of episiotomy or thirdor fourth-degree perineal tear (rather than an intact perineum or a firstor second-degree tear) was found in S4 to increase by a factor of 350 (p<0.001). The risk of TOC and of episiotomy or thirdand fourth-degree perineal tears was the lowest in S3 (p<0.001). In addition, significant differences were found with regard to the presence of postpartum haemorrhages and early initiation of breastfeeding initiation only in the sample as a whole. This effect could be explained by the construction of a multivariate logistic regression model (Wald test) between these variables and the rest of the covariables studied, observing that the obstetric unit size, the induced onset of labour and having an episiotomy or grade III-IV injury were associated with an increasing risk of having postpartum haemorrhage. Women who had an episiotomy or a grade III-IV injury were twice as likely to have a postpartum haemorrhage compared with women who had an intact perineum or a I-II degree tear [OR =2.5; CI95%:1.4–4.4]; induction of labour is also a risk for postpartum haemorrhage [OR =1.8; CI95%:1.1–3.1]. Moreover, doing skin-to-skin was associated with an increased probability of early initiation of breastfeeding onset [OR =45.9; 95%CI: 28.89–72.77] (Table 3). Table 3. Multivariate logistic regression between haemorrhage, breastfeeding and related covariables (N=2084). p-Value OR CI 95% for EXP (B) Lower Upper Haemorrhage S4 (Ref) 0.001 S1 0.045 0.3 0.1 0.9 S2 0.000 0.2 0.9 0.4 S3 0.014 0.4 0.9 0.8 Induced 0.028 1.8 1.1 3.1 Episiotomy 0.001 2.6 1.5 4.4 Constant 0.001 0.1 Breastfeeding Skin-to-skin contact 0.001 45.9 28.9 72.8 Constant 0.001 0.2 Furthermore, a multivariate logistic regression model was used in order to predict the variables that influenced the TOC. The related variables were OUS, parity, onset of labour, pharmacological stimulation of labour and episiotomy, with the OUS being the most influential variable (Table 4). Women in S3 have twice the probability [OR =2.3; 95% CI: 1.4–3.6] of having a TOC compared to those Int. J. Environ. Res. Public Health 2020,17, 8394 9 of 15 in S4; being primiparous increases the probability of TOC by almost twice [OR =1.9; 95% CI: 1.5–2.4]; inducing labour rises this risk by almost three times [OR =2.9; 95% CI: 2.3–3.8] in comparison with spontaneous onset of labour; the use of pharmacological stimulation and epidural analgesia are also risk factors for performing TOC [OR =1.3; 95% CI: 1.0–1.7, OR =1.7; 95% CI: 1.2–2.4, respectively] and performing an episiotomy increases the risk of TOC by five times [OR =5.3; 95% CI: 4.3–6.6]. The model obtained a percentage prediction of 73.4%. Table 4. Multivariate logistic regression of variables related to TOC (N=2084). p-Value OR 95% CI OR Lower Upper Unit Size S4 (Ref) 0.001 S1 0.498 0.8 0.5 1.4 S2 0.273 1.3 0.8 2.0 S3 0.001 2.3 1.5 3.6 Parity Multiparous (Ref) Nulliparous 0.001 2 1.6 2.4 Beginning of delivery Spontaneous (Ref) Induction 0.001 3 2.3 3.8 Pharmacologic stimulation None (Ref) Yes 0.011 1.4 1.1 1.8 Epidural analgesia None (Ref) Yes 0.001 1.7 1.2 2.4 Episiotomy None (Ref) Yes 0.001 5.3 4.3 6.6 Constant 0.001 0.1 Nagelkerke R2=0.379; percentage prediction =73.4%. 4. Discussion This cross-sectional study is part of a broader evaluation of maternity services in Spain and a centre in Ireland. This paper focuses specifically on the intrapartum TOC of low-risk women between health care professionals in obstetric units and the associated clinical and organizational factors. The majority of women whose labour care was initiated by a midwife remained in midwifery care throughout their labour and birth. However, there were statistical differences in the proportion of women transferred from midwifery care to obstetrician care according to the OUS (number of births). The hospitals with the lowest percentages of TOC were those in S1 and S4. These OUS groups had a transfer percentage of 29.4% and 31.2% respectively. Meanwhile, S3 had the highest transfer percentage (47.1%). These transfer rates brought sharply into focus the differences between midwifery and medical models of care. Out of all women, those in S4 (the highest number of births per year) were most likely to be provided one to one individualized care by a caseload midwifery team. These cases had the lowest frequency of oxytocin stimulation, epidural analgesia, episiotomy or severe perineal damage, and emergency caesarean section, and also registered among the lowest transfer percentages. Midwifery models recognize childbirth as a physiological process which has inherent sociocultural and psychological dimensions [ 16 ]. Our findings echo the strong existing evidence that suggests that continuity of care models achieve the best outcomes. For example, women who are attended in midwifery-led continuity models of care were found to be less likely to experience regional analgesia and severe perineal trauma [6,17].