Keywords
obstetrics - home birth - midwife-led unit - neonatal outcomes
Introduction
Although almost all women in Austria give birth in hospital, the percentage of births
which occur outside clinical settings is around 1.5% [1]. The following table ([Table 1]) shows the number of live births in Austria in
the years 2017 to 2021 as well as distribution of births according to place of birth. In
Austria, births planned as a delivery outside a clinical setting may either be organized as a
home birth in the mother’s place of residence or as a delivery in a midwife-led unit (the term
Geburtshaus i.e., birth house, was abolished when the law was
amended) [2].
Table 1
Live births in Austria and place of birth 2017–2021 (own
research).
Live births
|
2017
|
2018
|
2019
|
2020
|
2021
|
In all of Austria
|
86987
|
84804
|
84222
|
82950
|
85329
|
Place of birth (based on total number of live births)
|
Hospital
|
85626
|
83473
|
82915
|
81381
|
83635
|
Midwife-led unit
|
303
|
247
|
273
|
278
|
314
|
Mother’s place of residence
|
1012
|
987
|
940
|
1180
|
1253
|
During transportation
|
33
|
31
|
33
|
33
|
43
|
Other place of delivery
|
13
|
66
|
61
|
78
|
84
|
Hospital births in %
|
98.4
|
98.4
|
98.4
|
98.1
|
98
|
Live births born in a non-clinical setting in % (midwife-led unit, mother’s place
of residence)
|
1.51
|
1.46
|
1.44
|
1.76
|
1.84
|
In Austrian law, the Federal Law on Midwifery (Hebammengesetz –
HebG) [2] regulates the
involvement of midwives in the birth and the care of the neonate and their duty of care to
every pregnant woman, parturient and new mother (HebG idgF § 3, Para 1) and defines the range
of activities midwives may carry out autonomously (HebG idgF § 2, Para 1). It provides the
legal basis in clinical and non-clinical settings for midwives to autonomously provide
counselling, support and care during pregnancy, birth and postpartum to women with an
unremarkable medical history whose pregnancy follows a regular course. The legal limitations
which the Austrian Midwifery Law places on the autonomous activities of midwives oblige all
midwives to call in a physician without delay if there is a suspicion of anomalies or
anomalous conditions arise which could represent a danger to mother or baby and thereafter to
provide support and care only in accordance with doctor’s orders and in cooperation with a
physician (HebG idgF § 4, Para 1). This means that if an anomalous or dangerous health
condition is suspected or occurs, the home birth or birth in a midwife-led unit must not be
allowed to progress outside a clinical setting and the parturient must be transferred
immediately to hospital. This legal framework is the basis which significantly minimizes the
potential risks to mother and child of a home birth or a birth in a midwife-led unit.
The motivations of pregnant women which lead them to chose a non-clinical setting in which
to give birth have been investigated in different studies carried out in Australia by Sassine
et al. [3] and Hauck et
al. [4]. In addition to
wanting a home birth to avoid unnecessary medical interventions and medicalized routines,
pregnant women especially highlighted the continuous care provided by a midwife, the
undisturbed bonding phase, better support for breastfeeding through early placing of the
newborn at the breast, and the free choice of birthing position as important reasons to chose
a home birth [3]
[4]. The quality report on
non-hospital-based obstetric care in Germany cites self-determination, familiar surroundings
and a familiar midwife as the main reasons motivating women to give birth outside a hospital
[5].
As every woman has the right to freely chose where to give birth, opinions on giving birth
outside a clinical setting and opinions about the potential risks associated with giving birth
at home or in a birthing center are divided [6]
[7]. Even if the findings of the studies
presented below cannot be directly transferred to the conditions in Austria without
considering the respective framework conditions behind national healthcare policies, they
still make the differences in positions very clear.
The criticism levelled against home births or births in midwife-led units is mainly based
on the significantly higher risk of neonatal morbidity and mortality which has been
demonstrated in various studies. The studies by Wax et al. [8], Cheng et al. [9] and Grünebaum et al. [10] on this topic showed
that rates of maternal interventions such as epidural analgesia, episiotomies and surgical
deliveries and rates of birth trauma, postpartum bleeding and infections were lower with
planned home births. However, their results also showed that births in non-clinical settings
were associated with higher rates of neonatal complications, lower 5-minute Apgar scores, more
neonatal seizures, and higher neonatal mortality rates compared to births in hospital settings
[8]
[9]
[10].
The studies by Homer et al. [11], Jansen et al. [12], Cox et al. [13] and Kataoka et al. [14] came to very different conclusions and
reported that neonatal outcomes for non-hospital-based births were comparable to those of
births delivered in clinical settings due to lower intervention and complication rates. Their
studies found no differences in perinatal mortality rates, low 5-minute Apgar scores, meconium
aspiration, or the need to transfer the newborn to a pediatric clinic [11]
[12]
[13]
[14].
In their study, Hirazumi and Suzuki [15] reported no negative perinatal events for
births delivered in non-hospital settings under midwife-led care. Moreover, the studies by
Hildingsson et al. [16] and Forster et al. [17] described the continuous quality of care
and the birthing experience of non-hospital-based births as more satisfactory than births
which occurred in hospital.
The findings on intrapartum transfer rates of women to hospital who planned a home birth
vary considerably. The study by Anderson et al. [18] gave an intrapartum transfer rate of 8%,
whereas Amelink-Verburg et al. [19] reported a transfer rate of 31.9%, although it should be noted that the
frequency of intrapartum transfers of primiparae was significantly higher at 22.5%–56.3% than
that recorded for multiparae, which ranged from 4.4%–16.1% [20]. The most commonly stated reasons for
transferring a planned home birth to hospital in the literature are protracted labor, a
request for pain medication, a suspicion or occurrence of fetal stress, and abnormal
presentation or positional anomalies of the fetus [21].
A study carried out in Germany by Andraczek et al. [22] compared fetomaternal outcomes of births in
non-clinical settings requiring intrapartum transfer to hospital with deliveries in
midwife-led labor rooms in hospitals. According to their findings, in the group of planned
non-hospital-based births both maternal and neonatal outcomes after transfer to hospital were
significantly poorer as they were associated with higher rates of emergency caesarean section,
a longer first stage of labor, higher rates of postpartum hemorrhage, higher rates of 5-min
Apgar scores ≤ 7 and higher numbers of transfers of newborns to a pediatric clinic [22].
While the intervention rates and the maternal and neonatal morbidity and mortality rates
associated with hospital and non-hospital births have been analyzed in different studies, the
data on maternal and neonatal outcomes following transfer of a planned home birth or birth in
a midwife-led birthing center to hospital in Austria has barely been studied and is very
limited. An analysis of the outcomes following transfer of a planned home birth or midwife-led
birth outside a hospital setting to hospital will provide important information about the
process quality of non-hospital-based obstetric care.
As the intention was to close this research gap, this study aims to analyze maternal and
neonatal outcomes in Austria when planned home births or planned births in midwife-led centers
had to be transferred intrapartum to hospital.
Material and Method
Sample
The method used in this study was the evaluation of data from the Austrian Birth
Registry (Geburtenregister Österreich, GRÖ) from the Institute
for Clinical Epidemiology (IET) of Tirol Kliniken. The data used for analysis were obtained
from hospitals which used the docmentation box “transferred home births and transferred
births from midwife-led centers” when recording the birth (66 of 79 obstetric departments).
The chosen sample consisted of the data of singleton term births (excluding primary
caesarean sections, preterm and multiple births, vaginal births in breech presentation, and
births of neonates with a birthweight of less than 1500 g) delivered in the period from 1
January 2017 to 31 December 2021 (n = 286056). The births were divided into two groups for
comparison: planned hospital births and births marked in the Registry as home births or
births in midwife-led units which required intrapartum transfer to hospital and were
delivered in hospital (transfers of home births and of births in midwife-led
centers).
Data analysis
The two groups were compared with regards to the previously defined variables “parity”
and “maternal age”, “intrapartum interventions” (oxytocin, epidural analgesia, micro blood
gas analysis [MBU], tocolysis), “premature rupture of membranes”, “mode of delivery”
(spontaneous, vaginal surgical, emergency caesarean section, acute emergency c-section),
“increased postpartum bleeding”, “disorders of placental separation”, “sex and weight of the
newborn”, “neonatal Apgar scores” (5 min, 10 min), “umbilical cord pH”, “transfer to a
neonatal ward, NIMCU and NICU”, and “neonatal mortality rates” (antepartum, intrapartum,
postpartum).
Statistical data analysis was done using frequency description and univariate analysis
and presented using odds ratio (OR). Multivariate and bivariate logistic regression analysis
was done to obtain more specific predictions for neonatal outcome parameters (Apgar score,
pH value, transfer rate) and maternal outcome parameters (postpartum bleeding, disorders of
placental separation). The results are presented using the relative risk ratio (RRR). For
this, the items “maternal age”, “parity”, “mode of delivery”, “neonatal birthweight”,
“oxytocin”, “tocolysis”, “MBU”, “epidural analgesia”, “premature rupture of membranes”, and
“transferred home births and births in midwife-led units” were adjusted as independent
variables and a predictable risk was calculated.
The research proposal was presented to the Ethics Committee of the FH Gesundheitsberufe
Oberösterreich (University of Applied Sciences for Healthcare Professions in Upper Austria)
and was approved as unobjectionable (application for ethical approval: A-2021–055). The
statistical analysis was done at the IET using STATA (StataCorp. 2013. Stata Statistical
Software: Release 13. College Station, TX: StataCorp LLP).
Results
Population
Based on the total number of home births and births in midwife-led units recorded by
Statistik Austria and the home births and births in midwife-led units transferred to
hospital documented in the Austrian Birth Registry, the rate of home births and births in
midwife-led units which had to be delivered in hospitals ranges from 16.14% to
23.08%.
[Table 2] shows the number
and percentages of planned hospital births and planned home births and births in midwife-led
units which required intrapartum transfer to hospital in the sample population.
Table 2
Number and percentages of planned hospital births and planned
home births and births in midwife-led units which required intrapartum transfers to
hospital; maternal age and parity.
|
Total
|
Planned hospital births
|
Hospital transfers of planned home births and births in midwife-led units
|
|
N
|
%
|
N
|
%
|
N
|
%
|
Year
|
2017
|
58214
|
100
|
57961
|
99.57
|
253
|
0.43
|
2018
|
56651
|
100
|
56411
|
99.58
|
240
|
0.42
|
2019
|
56613
|
100
|
56249
|
99.36
|
364
|
0.64
|
2020
|
56360
|
100
|
56016
|
99.39
|
344
|
0.61
|
2021
|
58218
|
100
|
57826
|
99.33
|
392
|
0.67
|
Total
|
286056
|
100
|
284463
|
99.44
|
1593
|
0.56
|
Maternal age
|
< 20 years
|
4338
|
1.52
|
4327
|
1.52
|
11
|
0.69
|
20–34 years
|
218950
|
76.54
|
217805
|
76.57
|
1145
|
71.88
|
35–39 years
|
52330
|
18.29
|
51978
|
18.27
|
352
|
22.1
|
40–44 years
|
9891
|
3.46
|
9806
|
3.45
|
85
|
5.34
|
≥ 45 years
|
502
|
0.18
|
502
|
0.18
|
|
|
Data not available
|
45
|
0.02
|
45
|
0.02
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
Parity
|
Primiparae
|
143743
|
50.25
|
142784
|
50.19
|
959
|
60.2
|
Multiparae
|
142300
|
49.75
|
141666
|
49.8
|
634
|
39.8
|
Data not available
|
13
|
0
|
13
|
0
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
When the age cohorts in the two groups were compared ([Table 2]), the percentage distribution was similar
for the age cohorts 20–34 years, 35–39 years and 40–44 years. Only 11 women under the age of
20 and no woman over the age of 45 was recorded in the group of home births and births in
midwife-led units requiring an intrapartum hospital transfer.
An analysis of the data which focussed on maternal parity ([Table 2]) showed that births planned as a home birth
or in a midwife-led unit were transferred to hospital significantly more often (60.2%) if
the mother was a primipara compared to the transfer rates for multiparae (39.8%).
Intrapartum interventions
The percentage of births with intrapartum oxytocin administration ([Table 3]) was 0.39% lower for the group of home
births and births in midwife-led units requiring intrapartum transfer to hospital, but the
difference did not reach significance for this category (OR 0.97; CI: 0.84–1.12).
Table 3
Intrapartum interventions, mode of delivery, postpartum bleeding
and disorders of placental separation for planned hospital births and planned home births
and births in midwife-led units requiring intrapartum transfer to hospital.
|
Total (n = 286056)
|
Planned hospital births
|
Home births and births in a midwife-led unit transferred to hospital
intrapartum
|
OR
|
95% CI
|
N
|
%
|
N
|
%
|
n
|
%
|
(1) Reference category: no intervention
(2) Reference category: mode of delivery = spontaneous
(3) Reference category: no postpartum bleeding
(4) Reference category no disorders of placental separation
** p < 0.01, *** p < 0.001
|
Interventions (1)
|
Oxytocin intrapartum
|
41887
|
14.64
|
41660
|
14.65
|
227
|
14.25
|
0.97
|
0.84–1.12
|
MBU
|
11180
|
3.91
|
11090
|
3.9
|
90
|
5.65
|
1.48***
|
1.19–1.83
|
Tocolysis intrapartum
|
14787
|
5.17
|
14657
|
5.15
|
130
|
8.16
|
1.64***
|
1.37–1.96
|
Epidural analgesia
|
55356
|
19.35
|
55004
|
19.34
|
352
|
22.1
|
1.18**
|
1.05–1.33
|
Preterm rupture of membranes
|
73995
|
25.87
|
73573
|
25.86
|
422
|
26.49
|
1.03
|
0.92–1.15
|
Mode of delivery
|
Spontaneous
|
215394
|
75.3
|
214349
|
75.35
|
1045
|
65.6
|
|
|
Vacuum-assisted (2)
|
26352
|
9.21
|
26161
|
9.2
|
191
|
11.99
|
1.5***
|
1.28–1.75
|
Forceps-assisted (2)
|
158
|
0.06
|
156
|
0.05
|
2
|
0.13
|
2.63
|
0.65–10.62
|
Emergency c-section (2)
|
41211
|
14.410
|
40878
|
14.37
|
333
|
20.9
|
1.67***
|
1.48–1.89
|
Acute emergency c-section (2)
|
2733
|
0.96
|
2718
|
0.96
|
15
|
0.94
|
1.13
|
0.68–1.89
|
Not specified
|
208
|
0.07
|
201
|
0.07
|
7
|
0.44
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Postpartum bleeding (3)
|
1293
|
0.45
|
1283
|
0.45
|
10
|
0.63
|
1.39
|
0.75–2.60
|
Disorders of placental separation (4)
|
8684
|
3.04
|
8642
|
3.04
|
42
|
2.64
|
0.86
|
0.64–1.18
|
MBU to assess the condition of the fetus ([Table 3]) was carried out significantly more often (5.65%) in the group of
home births and births in midwife-led units requiring intrapartum transfer to hospital
compared to the group of non-transferred births (3.9%; OR 1.48, CI: 1.19–1.83).
During the birth, tocolysis was administered significantly more often (8.16%) in the
group of home births and births in midwife-led units requiring intrapartum transfer to
hospital ([Table 3]) compared to
5.5% for the group of non-transferred births (OR 1.64, CI: 1.37–1.96).
Epidural analgesia was administered to 22.1% of women in the group of home births and
births in midwife-led units requiring intrapartum transfer to hospital ([Table 3]); the rate of epidurals administered to
women in the group of planned hospitals births was 19.34% (OR 1.18, CI: 1.05–1.33).
The rate of preterm rupture of membranes was 26.49% in the group of home births and
births in midwife-led units requiring intrapartum transfer to hospital ([Table 3]) and therefore almost the same as for the
group of planned hospitals births where it was 25.86% (OR 1.03, CI: 0.92–1.15).
Mode of delivery, disorders of placental separation and postpartum bleeding
The rate of spontaneous births in the group of home births and births in midwife-led
units requiring intrapartum transfer to hospital was 65.6%, which was significantly lower
than in the comparative group where it was 75.35%. At the same time, the rates of vaginal
surgical delivery (vacuum-assisted delivery 11.99% vs 9.2%; OR 1.5, CI: 1.28–1.75;
forceps-assisted delivery 0.13% vs 0.05%; OR 2.63, CI: 0.65–10.62) and emergency caesarean
sections (20.9% vs 14.37%; OR 1.67, CI: 1.48–1.89) were higher. The acute emergency
caesarean section rate for the group of planned hospital births was 0.96% and was almost the
same as that of the group of planned home births and births in midwife-led units requiring
intrapartum transfer to hospital with 0.94% (OR 1.13, CI: 0.68–1.89) ([Table 3]).
Postpartum hemorrhage was recorded for ten of the women in the group of planned home
births and births in midwife-led units requiring intrapartum transfer to hospital ([Table 3]). This amounts to about 0.63%
of births and is therefore not significantly higher compared to the percentage of 0.45%
recorded for the group of planned hospital births (OR 1.39, CI: 0.75–2.60).
The rate of disorders of placental separation ([Table 3]) was recorded as 3.04% for planned hospital
births and therefore not significantly higher than the rate of 2.64% for planned home births
and births in midwife-led units requiring intrapartum transfer to hospital (OR 0.86, CI:
0.64–1.18).
Multifactorial regression analysis showed no significantly increased risk with regards
to the maternal outcome parameters “postpartum bleeding” (RRR 1.33; CI: 0.71–2.49) and
“disorders of placental separation” (RRR 0.84; CI: 0.62–1.14) for the group of home births
and births in midwife-led units requiring intrapartum transfer to hospital.
Neonatal outcome parameters
[Table 4] shows no
significant differences between newborns in both groups with regards to sex and
birthweight.
The 5-minute Apgar scores ([Table 4]) of the newborns of the group of home births and births in
midwife-led units requiring intrapartum transfer to hospital were significantly poorer
compared to those for the group of planned hospital births. An Apgar score between 0 and 4
was recorded for 2.32% of births (OR 10.51, CI: 7.52–14.67), a score between 5 and 8 for
5.59% (OR 1.62, CI: 1.31–2.01) and a score of 9 or 10 for 89.45% of births. By comparison,
the scores for the newborns of the group of planned hospital births were 0.24% for Apgar
scores between 0 and 4, 3.69% for scores between 5 and 8, and 95.87% with scores of 9 or
10.
Table 4
Sex and birthweight of newborns, Apgar scores after 5 and 10
minutes, umbilical cord pH, neonatal transfers, and perinatal mortality.
|
Total
|
Planned hospital births
|
Home births and births in a midwife-led unit transferred to hospital
intrapartum
|
OR
|
95% CI
|
N
|
%
|
N
|
%
|
N
|
%
|
(1) Reference category: Apgar score at 5 minutes = 9.10
(2) Reference category: Apgar score at 10 minutes = 9.10
(3) Reference category: umbilical cord pH < 7.25
(4) Reference category: infant transferred = no
** p < 0.01, *** p < 0.001
|
Sex
|
Male
|
146306
|
51.15
|
145495
|
51.15
|
811
|
50.91
|
|
|
Female
|
139746
|
48.85
|
138964
|
48.85
|
782
|
49.09
|
|
|
Not specified
|
4
|
0
|
4
|
0
|
|
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Birthweight (g)
|
1500–2499
|
4159
|
1.45
|
4138
|
1.45
|
21
|
1.32
|
|
|
2500–3999
|
253336
|
88.56
|
251950
|
88.57
|
1386
|
87.01
|
|
|
4000–6500
|
28561
|
9.98
|
28375
|
9.97
|
186
|
11.68
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Apgar scores at 5 minutes/groups (1)
|
0–4
|
711
|
0.25
|
674
|
0.24
|
37
|
2.32
|
10.51***
|
7.52–14.67
|
5–8
|
10592
|
3.7
|
10503
|
3.69
|
89
|
5.59
|
1.62***
|
1.31–2.01
|
9–10
|
274137
|
95.83
|
272712
|
95.87
|
1425
|
89.45
|
|
|
Not specified
|
616
|
0.22
|
574
|
0.2
|
42
|
2.64
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Apgar scores at 10 minutes/groups (2)
|
0–4
|
626
|
0.22
|
607
|
0.21
|
19
|
1.19
|
5.84***
|
3.69–9.25
|
5–8
|
3209
|
1.12
|
3177
|
1.12
|
32
|
2.01
|
1.88***
|
1.32–2.67
|
9–10
|
281597
|
98.44
|
280097
|
98.47
|
1500
|
94.16
|
|
|
Not specified
|
624
|
0.22
|
582
|
0.2
|
42
|
2.64
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Umbilical cord pH/groups (3)
|
< 7.0
|
896
|
0.31
|
884
|
0.31
|
12
|
0.75
|
2.74**
|
1.54–4.87
|
7–7.1
|
60132
|
21.02
|
59804
|
21.02
|
328
|
20.59
|
1.11
|
0.97–1.26
|
7.2–7.25
|
69218
|
24.2
|
68897
|
24.22
|
321
|
20.15
|
0.94
|
0.83–1.07
|
> 7.25
|
146642
|
51.26
|
145920
|
51.3
|
722
|
45.32
|
|
|
Not specified
|
9168
|
3.2
|
8958
|
3.15
|
210
|
13.18
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Infant transferred (4)
|
No
|
275660
|
96.37
|
274156
|
96.38
|
1504
|
94.41
|
|
|
Yes
|
10396
|
3.63
|
10307
|
3.62
|
89
|
5.59
|
1.57***
|
1.27–1.95
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Time of death
|
Died antepartum/IUFD
|
257
|
0.09
|
256
|
0.09
|
1
|
0.06
|
|
|
Intrapartum
|
7
|
0
|
6
|
0
|
1
|
0.06
|
|
|
Postpartum
|
82
|
0.03
|
78
|
0.03
|
4
|
0.25
|
|
|
Alive
|
285710
|
99.88
|
284123
|
99.88
|
1587
|
99.62
|
|
|
Total
|
286056
|
100
|
284463
|
100
|
1593
|
100
|
|
|
Moreover, the 10-minute Apgar scores for the newborns of the group of home births and
births in midwife-led units requiring intrapartum transfer to hospital were also
significantly lower ([Table 4]).
1.19% were in the category 0–4 points compared with 0.21% (OR 5.84, CI: 3.69–9.25); 2.01%
were in the category 5–8 points compared with 1.12% (OR 1.88, CI: 1.32–2.67), and 94.16%
were in the category 9 or 10 points compared with 98.47%.
An umbilical cord pH < 7.0 was recorded for 12 neonates (0.75%, OR 2.74, CI:
1.54–4.87) in the group of home births and births in midwife-led units requiring intrapartum
transfer, which was significantly higher than the 0.31% recorded for the newborns of the
group of planned hospitals births. When we reviewed all newborns with umbilical cord pH
values of 7.01–7.10, the rates were approximately the same for both groups ([Table 4]).
With a rate of 5.59% (OR 1.57, CI: 1.27–1.95), newborns from the group of home births
and births in midwife-led units requiring intrapartum transfer were transferred to a
pediatric clinic for monitoring significantly more often than the newborns from the group of
planned hospital births (3.62%) ([Table 4]).
Overall, one neonatal death antepartum, one intrapartum death and four postpartum
neonatal deaths were recorded for the group of home births and births in midwife-led units
requiring intrapartum transfer ([Table 4]).
When the Apgar scores at 5 and 10 minutes for the newborns of the group of home births
and births in midwife-led units requiring intrapartum transfer were evaluated,
multifactorial regression analysis showed significantly poorer scores both for the group
with a score of 0–4 and for the group with a score of 5–8 points ([Table 5]). Similarly, the risk of a poor umbilical
cord pH value was also significantly higher (RRR 2.13; CI: 1.16–3.91) for the group of
newborns with a pH of < 7.0 from the home births and births in midwife-led units group.
With a RRR of 1.41 (CI: 1.14–1.76), the transfer rates for newborns from the home births and
births in midwife-led units group requiring transfer to hospital were also significantly
higher.
Table 5
Multivariate regression analysis of neonatal outcome
parameters.
Home births and births in a midwife-led unit transferred to hospital
intrapartum
|
|
RRR
|
95% CI
|
|
RRR
|
95% CI
|
(1) Reference category: Apgar score at 1 minute = 9.10
(2) Reference category: pH > 7.25
(3) Reference category: transfer = no
* p < 0.05, ** p < 0.01, *** p < 0.001
|
Apgar score at 5 min groups (1)
|
Apgar score at 10 min groups (1)
|
0–4
|
10.24***
|
7.26–14.44
|
0 bis 4
|
5.95***
|
3.70–9.55
|
5–8
|
1.37**
|
1.10–1.70
|
5 bis 8
|
1.56*
|
1.10–2.23
|
Umbilical cord arterial pH (2)
|
< 7.0
|
2.13*
|
1.16–3.91
|
|
|
|
7–7.1
|
1.10
|
0.94–1.24
|
|
|
|
7.2–7.25
|
0.97
|
0.85–1.11
|
|
|
|
Infant transferred (3)
|
Yes
|
1.41*
|
1.14–1.76
|
|
|
|
Discussion
The Austrian Midwifery Law § 4(1) states that the autonomous exercise of the profession of
midwifery ends “when there is a suspicion of or occurrence of a condition which is anomalous
and dangerous for mother or child.” Such an event necessitates discontinuation of the birth at
home or in the midwife-led unit and a transfer of the mother and child to the nearest
maternity hospital. According to the data presented above, the birth was abandoned in 16.4% to
23.08% of cases where delivery was planned at home or in a midwife-led unit and the parturient
was transferred to hospital. With an average transfer rate of 18.92%, our findings lie between
the results of Anderson et al. [18], who reported an 8% transfer rate, and those of Amelink-Verburg et al.
[19], who recorded a
transfer rate of just under 32%.
Similar to the data by Blix et al. [20], our results show that just under ⅔ (60.2%) of parturients transferred
to hospital were primiparae.
If a homebirth or birth in a midwife-led unit is abandoned, the midwife is reacting to a
suspicion or the occurrence of anomalies and arranges the transfer of the mother to hospital.
In a clinical setting, such (suspected) diagnoses lead to higher concentrations of diagnostic
procedures or interventions. While the percentage of women given oxytocin was lower in the
group of home births or births in midwife-led units transferred to hospital, the rates for
micro blood gas analysis, tocolysis and epidural analgesia were higher ([Table 6]). Even though the precise indications and
diagnoses are missing in the registry data, these interventions indicate that, as was also
reported by Blix et al. [21], the most common reasons for abandoning a planned home birth or birth in
a midwife-led unit are protracted labor, the request for or necessity of pain relief, and a
suspicion of or the occurrence of imminent intrauterine asphyxia.
Table 6
Summary of interventions carried out intrapartum.
|
Total
|
Planned hospital births
|
Home births and births in a midwife-led unit transferred to hospital
intrapartum
|
OR
|
95% CI
|
N
|
%
|
N
|
%
|
N
|
%
|
**p < 0.01, ***p < 0.001
Reference category: (1) oxytocin = no; (2) MBU = no; (3) tocolysis = no; (4)
epidural analgesia = no
|
Oxytocin intrapartum
|
41887
|
14.64
|
41660
|
14.65
|
227
|
14.25
|
0.97 (1)
|
0.84–1.12
|
MBU
|
11180
|
3.91
|
11090
|
3.9
|
90
|
5.65
|
1.48*** (2)
|
1.19–1.83
|
Tocolysis
|
14787
|
5.17
|
14657
|
5.15
|
130
|
8.16
|
1.64*** (3)
|
1.37–1.96
|
Epidural analgesia
|
55356
|
19.35
|
55004
|
19.34
|
352
|
22.1
|
1.18** (4)
|
1.05–1.33
|
Similarly, the rates for vaginal surgical deliveries and emergency caesarean sections were
higher in the group of home births or births in midwife-led units transferred to hospital.
This is the logical consequence of abandoning delivery in a non-clinical setting and carrying
out interventions such as tocolysis, MBU or epidural analgesia. The rate of 0.94% for acute
emergency caesarean sections in the group of home births and births in midwife-led units
transferred to hospital is comparable with the rate of 0.96% for the group of planned hospital
births. The registry data do not show how long parturient women were already receiving care in
hospital before the decision for an acute emergency caesarean section was taken.
The postpartum hemorrhage rate was higher by 0.18 percentage points in the group of home
births and births in midwife-led units transferred to hospital while the rate of disorders of
placental separation was lower by 0.40 percentage points. Multifactorial regression analysis
did not find any significantly increased risk for these categories (RRR 1.33;
p = 0.712).
The Apgar scores at 5 and 10 minutes of newborns from the group of planned home births and
births in midwife-led units transferred to hospital were significantly poorer for the
categories 0–4 points, 5–8 points, and 9 and 10 points. Similarly, the group of home births
and births in midwife-led units transferred to hospital also had poorer cord pH values in the
category < 7.0, although the results for the group with cord pH values of 7.01–7.10 were
approximately the same. The rates of neonatal transfers to a pediatric clinic was another
outcome parameter. Here again, the transfer rate for newborns from the group of home births
and births in midwife-led units transferred to hospital was higher by 1.97%. Multifactorial
regression analysis of neonatal outcome parameters showed significantly higher risks for the
groups with Apgar scores of 0–4 points and 5–8 points, pH values of < 7 and higher rates of
transfer to a pediatric clinic.
The registry data do not provide information about the diagnoses or background of the
recorded fetal and neonatal deaths (1× antepartum, 1× intrapartum, 4× postpartum). It is
unfortunately not possible to answer the question whether these deaths could have been avoided
if the birth had been a planned hospital birth.
Limitations
When analyzing the data obtained from registries, one of the limitations is always the
quality of the data, as characteristics may have been recorded incorrectly. Moreover, it was
not possible to find out the reasons why the home birth or birth in a midwife-led unit needed
to be transferred to hospital nor the time of the transfer nor the causalities. Data from 13
(out of 79) obstetric departments in Austria could not be used for the analysis, as no valid
data could be obtained with regards to the characteristic “home birth or birth in a
midwife-led unit requiring transfer to hospital”.
Another limitation of the analysis is a potential performance bias based on the chosen
cohorts. During the birth, a life-threatening condition for mother and child is suspected or
occurs in the cohort of abandoned home births and births in midwife-led units, which is why
the mother and child have to be transferred to hospital. It was not possible to determine from
the registry data what the percentage of women with the same characteristics was in the group
of planned hospital births.
Conclusions
In Austria, an average of 18.92% of births planned as home births or births in midwife-led
units are transferred to hospital intrapartum; 60.2% of the affected women are primigravidae.
If a birth at home or in a midwife-led unit has to be abandoned, the midwife is responding to
a suspicion or the occurrence of anomalies and arranges for the mother to be transferred to
hospital. In a hospital setting, such (suspected) diagnoses result in a greater concentration
of diagnostic procedures or interventions. This means that home births or births in
midwife-led units which had to be abandoned have higher rates of intrapartum interventions
(MBU, tocolysis, epidural analgesia) and higher rates of vacuum-assisted deliveries and
emergency c-sections compared to planned hospital births. In addition, the neonatal outcome
parameters (Apgar score, cord pH, transfer rates) of neonates born to the group of planned
home births or births in midwife-led units which had to be transferred to hospital were
poorer.
From the perspective of hospital-based obstetrics, it is therefore understandable that a
birth in a non-clinical setting cannot be recommended even to pregnant low-risk women when
they are being advised about birth modes. This is based on the consideration that an acute
high-risk situation, which could require immediate life-saving interventions for the infant
and/or mother, can develop at any time during delivery and/or during the placental expulsion
phase.