Our study summarizes 14 years of experience of midwife-led births in an obstetric department of a university hospital. Main findings of our study are the low overall medical intervention rate, the good maternal and neonatal outcome and the significant proportion of secondary obstetrician involvement before, during or after delivery.
After all, 43% of women with an intended midwife-led birth had ante-, intra- or postpartum obstetrician involvement at some point. This number seems rather high, in view of the fact that women planning a midwife-led birth were already pre-selected according to their medical history and course of pregnancy. As can be expected, obstetrician involvement was highest in primiparous women. Women at ≥41 completed gestational weeks required labor induction, this explains the higher percentage of women with advanced gestational age in the group of women with secondary obstetrician involvement.
Nevertheless, the proportion of vaginal births (spontaneous or instrumental) was high and the overall caesarean section rate was low. Also the rate of other medical interventions (e.g. induction of labor, episiotomy) was low. Obstetrical anal sphincter injuries and postpartum hemorrhage with or without placental retention were as expected, comparable to the total population in the department. Our current policy is offering a hospital-based midwife-led birth model to low risk women. The results of our study support the appropriateness of the predefined exclusion criteria as well as the predefined criteria for secondary obstetrician involvement for our midwife-led birth model.
Overall, maternal and neonatal outcome in the complete cohort of all intended midwife-led births was very good and the overall transfer rate of newborns to the NICU was low. The higher rate of arterial umbilical cord pH < 7.10 and transfer of newborns to the NICU in the group of midwife-led births with secondary obstetrician involvement reflects ante-, intra- and postpartum complications and indirectly supports the appropriateness of our criteria to involve an obstetrician for the safety of mother and child, when these criteria are met.
Regarding the frequency of obstetrician involvement, Bodner-Adler et al. describe a low transfer rate in their study of midwife-led care at a tertiary care center in Austria : In contrast to our results, the secondary obstetrician involvement among midwife-led births in low risk women in the study by Bodner-Adler et al. was only 7% of a total of 2123 intended midwife-led births over a period of 10 years. One important explanation for the discrepancy to our results may be that the majority of women (74%) in their study were multiparous women. Another explanation might be a different definition of obstetrician involvement. The caesarean section rate among these births was 7%, while 93% women had spontaneous or instrumental vaginal births. Matched with low risk women assigned to primarily obstetrician-led births there was a significant decrease in interventions and no adverse maternal or neonatal outcomes .
Another more recent study of midwife-led care during birth at a tertiary care center in Germany by Merz et.al. showed a similar obstetrician involvement rate as our study (50%), while the caesarean section rate (9.3%) in the intended midwife-led birth group was almost the double of the rate in our study. The authors found higher odds for transfer from midwife-led births to standard obstetric care for nulliparous women, higher age and increased birthweight (+ 100 g) .
It needs to be noted that the rate of 2.6% of intended midwife-led births compared to the total number of births at our institution was low. This may have several reasons: One reason might be that the proportion of high risk pregnancies at our tertiary care perinatal center is high and thus many women not meeting our relatively strict selection criteria are excluded. Additionally, during the evaluated 14 years, the number of births accompagnied by free practicing midwife in our hospital increased, which in fact may be a direct competition to our midwife-led delivery model with resident midwives. Furthermore, our midwife-led birth setting within the hospital might not be widespread known or the hospital-based setting and atmosphere does not meet some womens’ expectations of a natural birth. Results of our study including favorable maternal and neonatal outcome and low medical intervention rate in a hospital-based but midwife-led birth setting can be used to better inform women in order to make a well-informed choice and help making our in-hospital midwife-led birth model more popular.
Maillefer et al. found that women and health professionals are favourable towards the development of midwife-led units in university hospitals, women notably focusing on the continuity of care . Many women with low risk pregnancies wish to give birth in the most natural way as possible, with as little medical interventions as necessary and with continuity of care in a non-medical atmosphere, involving as little attending people as possible. They want to ensure safety for themselves and their child. Systematic reviews comparing midwife-led continuity models to other models of care for childbearing women provide good evidence that low risk pregnant women under midwife care experience less medical intervention and more satisfaction with at least comparable adverse outcomes [15, 16]. Our results and experience with a low overall medical intervention rate and favorable maternal and neonatal outcome are in line with evidence-based benefits of midwife-led maternal care and birth models.
We need to emphasize on the advantages of an in-hospital midwife-led birth model, where the same rooms are being used and secondary obstetrician consultation is available immediately and at any time. As medical interventions in low risk pregnancies and during physiological course of labor are rather associated with negative consequences than significant benefits for mother and child [12,13,14], more interest should focus on avoidance of unnecessary interventions, continuous consideration of interventions’ appropriateness and well defined selection criteria for midwife-led maternity care and birth models.
Our study concentrated on women with low risk pregnancies. Current studies are now focusing on the evaluation of clinical- and cost-effectiveness in midwifery care models for women experiencing complex pregnancy and women with chronic medical conditions [20,21,22]. In a randomized controlled trial comparing midwife-coordinated maternity care intervention with standard care for women with chronic medical conditions, de Wolff et al. found an increased level of satisfaction with maternity care among women who received midwife coordinated maternity care intervention .
A further important aspect is the view of midwives in our team. The option of keeping full responsibility for a woman during childbirth in a midwife-led birth setting is sometimes challenging, but at the same time very satisfying. Interestingly the authors believe that even the team spirit between midwives and obstetricians is promoted by midwife-led births.
In summary, midwife-led birth settings within a clinical obstetric department offer primary and continuous care by a midwife without missing out on the advantages of the hospital’s facilities and infrastructure, ensuring safety for mother and child during the entire course of labor. According to our study results and our daily experience, an in-hospital midwife-led birth model for women with low risk pregnancies is safe and represents an interesting offer to women looking for less “medicalized” birth care. Nevertheless, it must be considered that in almost half of the cases an obstetrician involvement is necessary. Despite the high rate of obstetrician involvement, the caesarean section rate as well as the instrumental vaginal birth rate and episiotomy rate are very low and maternal and neonatal outcome is good. This is probably achieved by using the same hospital’s facilities and resources for midwife-led births as well as for standard midwife-obstetrician-led births in case of complications at any time. A further positive effect is that the midwives and doctors work together in the same unit as a team and are not artificially separated.
The retrospective study design, the small numbers and the lack of matching with primarily obstetrician-led births limits the generalizability of our findings and applicability in practice. Data about medical intervention rate and maternal and neonatal outcome of low risk women with obstetrician-led births were not evaluated. Our results only focus on midwife-led births in low risk pregnancies including those with secondary obstetrician involvement. Extrapolation of outcomes for the entire collective of low risk women therefore is not possible and limits a general statement. Future evaluations should focus on the criteria and appropriateness of specialist’s referral used to determine antepartum care and birth models offered to women.
While systematic reviews of midwifery care, mostly conducted in the United Kingdom, provide good evidence for cost effectiveness in midwife-led birth models for women with low risk pregnancies, information on cost effectiveness of midwifery care for women with complex pregnancy is limited [15, 16, 20, 23, 24]. As cost effectiveness needs to interpreted in relation to the different health systems in Europe and to our knowledge there is no such evaluation for Switzerland, an economic evaluation of our midwife-led birth model compared to the standard care within our setting is required.