Shinshu Med J, 67⑵：91～103, 2019

Autonomic Nervous System Changes in Term Infants during Early
Skin-to-skin Contact (SSC) : Examination of SSC Effectiveness andthe Influence of Meconium-stained Amniotic Fluid
Akiko Haga＊, Chitaru Tokutake, Kesami Sakaguchi, Atsuko Samejima
Miki Yoneyama, Masayoshi Ohira, Motoki Ichikawa and Makoto Kanai＊
School of Health Science, Shinshu University School of Medicine

Aim : To determine the effects of early skin-to-skin contact (SSC) and the influence of meconium-stained amniotic fluid (MSAF) on infants who satisfied the SSC indications by examining the changes in autonomic nervous
system and physiological indices in term infants born with normal vaginal delivery.
Methods : Our study population included cases that satisfied indications for implementing SSC. Study A included
12 infants who underwent SSC (SSC group) and 10 who did not (non-SCC group), and Study B included 9
infants with MSAF (SSC with MSAF group) and 12 without it (SSC with clear AF group). We measured heart
rate variability (HRV), heart rate (HR), oxygen saturation (SpO2), state of sleep-wakefulness (measured continuously for 2h after birth), respiratory rate (RR), and body temperature (measured every 15 min).
Results : In Study A, irrespective of the presence/absence of SSC, sympathetic nervous system (SNS) activities
accelerated at 1h after birth, but after 2h, the SNS activity was suppressed in the SSC group. During SSC, SpO2
progressed within the normal range of ＞95 ％, and the infants were significantly more often in a state of sleep.
In Study B, there was no difference in HRV, HR, RR, temperature, SpO2, and state of sleep according to thepresence/absence of MSAF.
Conclusions : SSC is effective in inducing a state of rest because it induces a state of sleep and suppresses SNS
hyperactivity at 2h after birth. When SSC indications are satisfied, we demonstrated, for the first time, that
MSAF has no adverse effect on infants. Shinshu Med J 67 : 91―103, 2019
(Received for publication September 26, 2018 ; accepted in revised form November 5, 2018)
Key words : autonomic nervous system, early skin-to-skin contact, heart rate variability,
meconium, oximetry
on preterm infants in the neonatal intensive care

Ⅰ Introduction

unit. SSC was presented by the WHO4） in 1996, andEarly skin-to-skin contact (SSC) is performed

along with “Evidence for the Ten Steps to Successful

during the sensitive period1） when maternal-infant

Breastfeeding” by the WHO5）, SCC is recommended

attachment develops immediately after birth. SSC isworldwide as a means to establish a mother-infant2）

the infant care performed by placing a naked term
infant in a prone position on the mother’s chest after
birth and differs from kangaroo care3）

performed

relationship.
Respiratory and cardiovascular systems in the
neonate rapidly change during the transition fromintrauterine to extrauterine life. Respiratory and cir-＊Corresponding author : Akiko Haga, Makoto Kanai

culatory functions are immature in neonates, but

School of Health Science, Shinshu University School of

homeostasis is maintained through interactions

Medicine, Shinshu University School of Medicine, 3-1-1
Asahi, Matsumoto, Nagano 390-8621, Japan
E-mail : akihaga@shinshu-u.ac.jp (Haga)
makotok@shinshu-u.ac.jp (Kanai)

No. 2, 2019

between the sympathetic nerve system (SNS) andparasympathetic nerve system (PSNS). SSC provides
benefits, such as maintaining respiratory and heart91

Haga・Tokutake・Sakaguchi et al.
Table 1

Indications for early mother-infant skin-to-skin contact after vaginal deliveries, discontinuation
criteria, and implementation methods2） in Japan

Indications

Mother : The mother herself is willing to engage in “early mother-infant skin-to-skin contact.”
Vital signs are stable. The mother is not exhausted. The physician or midwife does not observe
any contraindications.
Infant : Absence of non-reassuring fetal status. No asphyxia neonatorum (1-min and 5-min Apgar
score ≥8). Term newborn. Not a low-birth-weight infant. The physician, midwife, or nurse does
not observe any contraindications.

Discontinuation
criteria

Mother : Drowsiness. Physician or midwife judges that it is contraindicated.
Infant : Presence of a breathing problem (including apnea and gasping respiration). SpO2 : ＜90 ％.

Limp, little vitality. Enters a sleeping state. The physician, midwife, or nurse judges that it iscontraindicated.

Implementation
methods

・Explain “early mother-infant skin-to-skin contact” when drafting the birth plan.
・Start as soon as possible after birth. It is preferable to continue for 30 min or more or until
breast-feeding.
・Set the upper limit to continue at within 2 hours, and conclude at the point when the infant falls
asleep or the mother becomes drowsy.
Mother：Confirm that the mother wants “early mother-infant skin-to-skin contact”. Elevate theupper body (around 30°is preferable). Wipe away sweat on the chest and abdomen. Hold the nudebaby. With the mother and infant chest-to-chest, firmly support the child with both hands.
Infant : Dry the infant off. Position the infant’s head turned to one side so the infant can breathe
easily without the nasal cavity becoming obstructed. Cover the infant with a warmed bath towel.
Attach the probe of a pulse oximeter to a lower limb, or the staff member in charge remains in
attendance during implementation and does not leave the mother and child alone. The parameters
below are monitored, checked, and recorded. Respiratory status : Watch for labored breathing,retractive breathing, tachypnea, groaning, and apnea. Feeling cold, cyanosis .Vital signs (heart rate,
respiratory rate, body temperature, etc.). Behavior of mother and infant during implementation. At
the conclusion record vital signs and the infant’s condition.

rate stability, maintaining temperature6）7）, and pro8）

absence of meconium-stained amniotic fluid (MSAF).

to neonates. Conversely, theMSAF is not a rare phenomenon ; it is observed inneed for cardiopulmonary resuscitation during SSC

an average of 14 ％ deliveries10）, but in severe cases,

has also been reported9）. Therefore, in 2012, theit is also associated with respiratory condition at birth.

points to bear in mind in regard to the implementa-

However, no studies have examined ANS during SSC

moting breastfeeding

2）tion of “Early Mother-Infant Skin-to-Skin Contact”

according to the presence/absence of MSAF.

in Japan outlined indications and discontinuation

Here in Study A, we examined the effects of SSC

criteria. However, no studies have examined the au-

according to whether the infants underwent SSC ; intonomic nervous system (ANS) in neonates depend-

Study B, we examined the influence of MSAF bying on SSC implemented in accordance with the in-changes in the ANS and physiological indices. In this

dications.

study, heart rate variability (HRV) analysis, widely
2）

Moreover, indications for SSC

list the following

applied as an evaluation of ANS11）12）, was used.

exclusion criteria : preterm infants ; a low-birth-Ⅱweight infant ; presence of non-reassuring fetal
status ; asphyxia neonatorum ; and contraindications

A

Methods

Subjects

by the physician, midwife, or nurse (Table 1). Con-We obtained informed consent from the mothers

versely, the indications do not mention the presence/of the term infants who underwent normal vaginal

92

Shinshu Med J

67

SSC : autonomic nervous system changesi
The measuring timeof Study A（Mean±SD）①just after birth②1hour③2hours

SSC Groupn(N=12)（

Study A23.5±12.7

Non-SSC Group）73.8±9.2

10

10(N=10)
10

SSC with MASF
(N=9)
Group
Study B

10

30

o t

32.0±12.1

SSC with Clear AF
Group (N=12)The measuring timeof Study B

64.2±15.330523.5±12.7①Pre SSCk②SSC3073.8±9.2c

10 10③SSC last10④Post SSC

HRV(heart rate variability)/ Heart rate：Continuous recording
Measurement
contents

SpO2(Pre-ductal and post-ductal)：Continuous recording
Respiratory rate, Temperature： Every 15 minutes
State(Sleep-wakefulness)：Continuous recording
Fig. 1

Study designdeliveries from 2008 to 2011. We included 12 infants

study, SSC was performed for 30 min to 2h, and datawith SSC (SSC group) and 10 without SSC (non-SCC

were collected up to 10 min after SSC completion.

group) for Study A and 9 infants with MSAF (SSC

For SSC, the naked infant was placed skin-to-skinwith MSAF group) and 12 without MSAF (SSC within the prone position upon the mother’s chest in aclear AF group) for Study B. SSC was promoted insupine position (maternal upper body angle, approxi-

accordance with our hospital implementation criteria,

mately 17°). During SSC, the infant’s head position

2）

which satisfy the indications published in 2012 .

turned to one side and was covered with a warmed

This study was approved by the institutional ethics

bath towel, and the mother firmly supported it withcommittee of Shinshu University School of Medicine

both hands. In the non-SSC group, measured data(approval number 1093).

were collected with the infant lying in the supine po-

Bsition in a cot in the delivery room. Observations

Measurement procedures
We designed the protocol for an observational

study (Fig. 1). We took measurements from term in-were performed at room temperature between
24 ℃-28 ℃ and 30 ％-40 ％ humidity.

fants born between 8 am and 6 pm, including contin-

For Study A, we analyzed the mean of data ob-uous measurements of HRV, heart rate (HR), oxygen

tained at three time points, i.e., just after birth (forsaturation (SpO2), and state of sleep-wakefulness for

10 min after birth), after 1h (for 10 min at 55-65 min

2h after birth, and measurements of respiratory rate

after birth), and after 2h (for 10 min at 110-120 min(RR) and body temperature every 15 min. We col-after birth). SSC was commenced at 23.5±12.7 minlected basic infant information, including gestational

after birth and was conducted for 73.8±9.2 min. Forage, Apgar score, umbilical arterial blood pH, andStudy B, we analyzed the mean of data obtained atbirth weight, from medical charts.

four time points, i.e., PreSSC (for 5 min prior to com2）

According to the method of SSC implementation ,mencing SSC), SSC30 (for 10 min at 25-35 min after

it is preferable to commence SSC as early as possiblecommencing SSC), SSClast10 (for 10 min prior toafter delivery and perform it for ≥ 30 min. In thiscompletion of SSC), and PostSSC (for 10 min afterNo. 2, 201993

Haga・Tokutake・Sakaguchi et al.
Table 2

Gestational age (weeks)
1-min Apgar score (points)
5-min Apgar score (points)
Umbilical artery blood pH
Neonatal Birth weight (g)Data are presented as mean±SD.

Infants’ Characteristics in Study A
SSC Group (N＝12)

Non-SSC Group (N＝10)p-value†39.2±1.0
8.4±0.7
9.6±0.57.35±0.04
3,038.2±315.4

39.3±1.4
8.8±0.4
9.9±0.3
7.32±0.07
3,011.4±296.9

N.S.
N.S.
N.S.
N.S.
N.S.

† : Student’s t-test, N.S. : not significant

completion of SSC). In the SSC with MSAF group,

arteriosus (right foot), continuously for 2h after birth

SSC was commenced at 32.0±12.1 min after birthand used the means of each 1 min for analysis.

and was conducted for 64.2±15.3 min, whereas inE

State of sleep-wakefulness

the SSC with clear AF group, SSC was commenced

We analyzed the state of sleep-wakefulness in ne-

at 23.5±12.7 min after birth and was conducted foronates by the classification of the Brazelton Neonatal73.8±9.2 min. No significant differences were found

Behavioral Assessment Scale15）. The scale classifies

in the times of commencement and durations be-

and evaluates the state of sleep-wakefulness into six

tween the groups.

stages : state 1 (sleep) to state 6 (crying). Video re-Ccordings were used for evaluation, and we calculated

Heart rate variability analysis
HRV serves as an indicator of cardiac autonomic

nerve activity by instantaneously measuring varia11）-13）

tions in the R-R interval per beat

. An Activtrac-

the ratio of the state of sleep (states 1-2) for all observation periods.
F

Statistical analysis

er AC-301A (GMS, Japan) was used for continuously

Data obtained was statistically analyzed using

recording the R-R interval, and time series data for

SPSS21 software. Student’s t-test and the χ 2 -test

1 min were obtained for power spectral analysis by

was used for comparing data between the two

Memcalc/Tarawa (Suwa Trust, Japan). The analysis

groups, and the Bonferroni method was used for

was performed with a low frequency (LF) compo-

multiple comparisons after one factor repeated mea-

nent of 0.04-0.15 Hz and a high frequency (HF) com-sures ANOVA. We considered p-values ＜0.05 to beponent of 0.15-0.80 Hz

12）considering the RR of in-statistically significant.

fants. The LF component reflects SNS and PSNS

Ⅲ

activities, whereas the HF component reflects only
PSNS activity. We used the LF/HF as an indicatorAof SNS activity, and the HF component normalized

１

units (HFnu) calculated by HF/(LF＋HF) as an indi-

Results

Study A : SSC effectiveness
Infants’ background information

Table 2 shows infants’ background information. No

cator of PSNS activity13）.

differences were found between the two groups inD

the mean gestational age, Apgar score, umbilicalPhysiological indices
The HR was measured simultaneously with HRV,

and the RR was measured visually for 1 min. Tem-arterial blood pH, and birth weight.
２

Changes in heart rate variability

perature was measured at the infant’s forehead

Upon comparing the LF/HF between the two

using an infrared skin thermometer. SpO2 was mea-groups, no differences were found just after birth or

sured using an N-600 pulse oximeter (Nellcor, Covid-

1h after birth ; however, after 2h, LF/HF was signifi-

14）ien). Concerning postnatal circulation , we measured

cantly lower in the SSC group than in the non-SSC

pre-ductal SpO2 , reflecting systemic circulationgroup (Fig. 2A). Upon examining the shift in LF/HF

before the ductus arteriosus (sensor attached to theover the three points in time, the SSC group showed

right hand), and post-ductal SpO2, after the ductus

a significant increase in LF/HF only during the94

Shinshu Med J

67

SSC : autonomic nervous system changes

A

Changes in LF/HF

SSC Group (N=12)
Non-SSC Group (N=10)

＊＊†

12.0

＊‡
＊†
10.0

8.0
＊†
7.1

6.0
5.9
4.7

4.0

3.4

2.0

2.5
＊p<0.05

1.7＊＊p<0.01

0.0
Just after birth

B

1h

2h

SSC Group (N=12)

Changes in HFnu

Non-SSC Group (N=10)

100

80

60
(%)
40

42.0
37.9

37.1

36.9
28.6

20

26.0

0
Just after birth1h2hFig. 2

Changes in heart rate variability for 2h after birth (Study A)
A : Changes in LF/HF B : Changes in HFnu
Data are presented as mean±SD. †one factor repeated measures ANOVA ; ‡Student’s t-test
Just after birth represents data measured for 10 min after birth, 1h represents data measured for 10 min
at 55-65 min after birth, and 2h represents data measured for 10 min at 110-120 minutes after birth.

period from just after birth to 1h after birth. On thechanges in either group (Fig. 2B).

other hand, the non-SSC group showed significant

３

increases from just after birth to 1h after birth andfrom just after birth to 2h after birth (Fig. 2A).

Changes in physiological indicesUpon comparing HR between the two groups, nosignificant differences were found at the three time

With regards to HFnu upon comparing the twopoints. We found no significant difference in the shiftgroups, no significant difference was found at thein the HR over the three time points in the SSC

three time points. Upon examining the shift in HFnu

group. However, the HR significantly decreased fromover the three time points, we found no significant

just after birth to 2h after birth in the non-SSC

No. 2, 201995

Haga・Tokutake・Sakaguchi et al.

SSC Group (N=12)A

Changes in HR

Non-SSC Group (N=10)

180

＊＊†

HR

per/min）

170
160
159.1
150

155.0

152.9
147.6

140

144.7

141.6

130
120

Just after birthB1h＊＊p<0.01

2h

SSC Group (N=12)
Non-SSC Group (N=10)

Changes in RR
70

per/min）

60

RR

＊＊†

50

58.8
55.8

55.4
53.8
52.0

51.7

40

Just after birthC1h＊＊p<0.01

2h

SSC Group (N=12)
Non-SSC Group (N=10)

Changes in Temperature

38.0

＊＊‡

＊＊†

T（

）

37.5

37.0

37.2
36.9
36.8
36.7

36.5

36.7
36.6

36.0

Just after birth1h2h＊＊p<0.01

Fig. 3 Changes in physiological indices for 2h after birth (Study A)
A : Changes in heart rate B : Changes in respiratory rate C : Changes in temperature
Data are presented as mean±SD. †one factor repeated measures ANOVA ; ‡Student’s t-test
Just after birth represents data measured for 10 min after birth, 1h represents data measured for 10 min
at 55-65 min after birth, and 2h represents data measured for 10 min at 110-120 minutes after birth.

96

Shinshu Med J

67

SSC : autonomic nervous system changes

group (Fig. 3A).

Pre-ductal SpO2 reached 90 ％ after 10 min in theNo significant difference was found in our compar-

SSC group and after 7 min in the non-SSC group,ison of RR between the two groups at any of thewhereas post-ductal SpO 2 reached 90 ％ after 11

three time points. Upon examining the shift in RR

min in the SSC group and after 12 min in the non-over the three time points, we found no significant

SSC group, with no significant differences betweenchanges in the SSC group, but the RR significantly

the groups (Fig. 4A,B). In addition, SpO2 shifted

decreased from just after birth to 1h after birth inalmost to ＞95 ％ during SSC, and no hypoxia was

the non-SSC group (Fig. 3B).

observed.

The temperature at 2h after birth was significant-５

State of sleep-wakefulness

ly higher in the SSC group than in the non-SSC

In the SSC group, sleep state accounted for 9.7 ％group. A significant rise was found in the shift in the(86 min) during total SSC time (885 min, n＝12). In

temperature from 1h to 2h after birth in the SSC

the non-SSC group, we examined the state of sleep

group, whereas there was no significant change induring the mean 73.8 min period of SSC after thethe non-SSC group (Fig. 3C).

SSC start time of 23.5 min after birth ; sleep state４

accounted for 1.3 ％ (9.6 min) during total observa-

Changes in SpO2

pre-ductalA

post-ductal
100
95
90

SpO2(%)

85
80
75
70
65

SSC

60
0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120

Minutes after birthpre-ductal

B

post-ductal
100
95
90

SpO2(%)

85
80
75
70
65
60
0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120

Minutes after birthFig. 4

Neonatal pre- and post-ductal SpO2 levels during 2h after birth (Study A)
A : SSC Group B : non-SSC GroupIt shows every 1 min for 30 min, and every 5 min for 2h. Data are presented as mean±SD.
SSC was commenced at 23.5±12.7 min after birth and was conducted for 73.8±9.2 min.
No. 2, 201997

Haga・Tokutake・Sakaguchi et al.
Table 3

Infants’ Characteristics in Study B

SSC with MSAF Group(N＝9)

SSC with clear AF Group(N＝12)

p-value†40.2±0.7
8.7±0.5
9.2±0.4
7.37±0.04
3010.9±342.9

39.2±1.0
8.4±0.7
9.6±0.57.35±0.04
3,038.2±315.4

N.S.
N.S.
N.S.
N.S.
N.S.

Gestational age (weeks)
1-min Apgar score (points)
5-min Apgar score (points)
Umbilical artery blood pH
Neonatal Birth weight (g)Data are presented as mean±SD.

†：Student’s t-test, N.S. : not significant

tion time (738 min, n＝10), indicating that the SSC

period (885 min), with no significant differences be-group had a significantly higher rate of sleep (p＜tween the groups.

0.05).
B

Study B : Influence of MSAF

１

Infants’ background information

Ⅳ
A

Discussion

Study A : SSC effectiveness

Table 3 shows infants’ background information. No

Comparison of LF/HF between term infants born

differences were found between the two groups invia normal vaginal delivery in the SSC and non-SSC

the mean gestational age, Apgar score, umbilicalgroups revealed no significant differences, both justarterial blood pH, and birth weight.

after birth and at 1h after birth. At 2h after birth,

２

LF/HF in the SSC group was significantly lower

Changes in heart rate variability
Upon comparing LF/HF between the two groups,

than that in the non-SSC group. In both groups, LF/

we found no significant differences at all four time

HF at 1h after birth was significantly higher thanpoints (Fig. 5A). We found no significant differences

the respective LF/HF just after birth ; however, it

at all four time points in HFnu between the two

decreased somewhat in the SSC group from 1-2 hgroups (Fig. 5B).

after birth, whereas the non-SSC group increased

３slightly during this period. Our results suggest that

Changes in physiological indices
We found no significant differences at all four time

the SNS activity is accelerated at 1h after birth re-points for the HR (Fig. 6A) and RR (Fig. 6B) andgardless of whether SSC is performed, whereas per-temperature (Fig. 6C) between the two groups.

forming SSC at 2h after birth suppressed SNS activi-

４ty. This may be attributable to the fact that the SSC

Changes in SpO2
Pre-ductal SpO2 reached 90 ％ after 8 min in thegroup infants were significantly more often in a

SSC with MSAF group and after 10 min in the SSC

sleep state. Results pertaining to the non-SSC groupwith clear AF group, whereas post-ductal SpO2

are similar to those reported from a previous

reached 90 ％ after 10 min in the SSC with MSAF

study16）. It is generally thought that the ANS pre-group and after 11 min in the SSC with clear AF

dominantly acts via the PSNS throughout the fetal/group, with no significant differences between the

neonatal period17）; however, in infants just after

groups (Fig. 7A, B). In addition, in both groups, SpO2

birth, the SNS predominantly acts to maintain ho-

shifted almost to ＞95 ％ during SSC, and no hypoxia

meostasis during adaptation to the changing envi-

was observed.

ronments.

５

State of sleep-wakefulness

Conversely, no significant differences with respect

In the SSC with MSAF group, sleep state account-

to HFnu were observed between the SSC and non-ed for 13.3 ％ (77 min) during the SSC period (578

SSC groups as well as in either of the groups overmin), and in the SSC with clear AF group, sleep

time. Our results do not completely contradict thestate accounted for 9.7 ％ (86 min) during the SSC

LF/HF expected based on the relationship of98

Shinshu Med J

67

SSC : autonomic nervous system changes

A

SSC with MSAF Group (N=9)

Changes in LF/HF

SSC with clear AF Group (N=12)14.0
N.S.:not significant

N.S.

12.0
10.0
N.S.

N.S.

8.0
6.9

6.0

2.0

5.5

N.S.

4.0

5.2

5.0
4.5

4.0

2.7

2.3

0.0
PreSSC

SSC30

SSC last10

SSC with MSAF Group (N=9)
SSC with clear AF Group (N=12)

Changes in HFnu

B

PostSSC

100
N.S.:not significant
80

(%)

60
N.S.

N.S.

N.S.

N.S.

40
39.2

36.1

35.6
31.7

20

26.2

27.8

35.4
29.3

0
PreSSC

SSC30

SSC last10

PostSSC

Fig. 5

Changes in heart rate variability for PreSSC, SSC30, SSClast10, and PostSSC (Study B)
A : Changes in LF/HF B : Changes in HFnu
Data are presented as mean±SD.
PreSSC represents data measured for 5 min prior to commencing SSC, SSC30 represents data measured
for 10 min at 25-30 min after commencing SSC, SSClast10 represents data measured for 10 min prior tocompletion of SSC, PostSSC represents data measured for 10 min after completion of SSC.

opposing control of SNS and PSNS activity. We may

studies.

not have detected a clear opposing relationship be-

Among the physiological indices, no difference

cause the period just after birth requires adaptation

was observed in the HR and RR according to theto extrauterine life and the ANS is unstable until ap-

presence/absence of SSC ; however, at 2h after birth,18）

proximately 3 days after birth . However, we weretemperature was significantly higher in the SSC

unable to clarify whether this result was due togroup than in the non-SSC group. Moreover, in the

ANS instability just after birth or some other mech-

SSC group, the temperature significantly increased

anism. Therefore, this appears to be a limitation of

from 1h to 2h after birth. This result is comparable

this study that needs to be investigated in futurewith previous results6）7）; thus, the temperature-

No. 2, 201999

Haga・Tokutake・Sakaguchi et al.
SSC with MSAF Group (N=9)

Changes in HRA

SSC with clear AF Group (N=12)180
N.S.:not signifiicant

N.S.
N.S.

170
N.S.

N.S.

HR

per/min

160
159.6
150

152.9

153.2

154.7
151.5

150.8
144.7

140
141.2
130

120

PreSSC

SSC30

B

SSC last10

SSC with MSAF Group (N=9)

Changes in RR
70

PostSSC

SSC with clear AF Group (N=12)

N.S.

RR

per/min

N.S.:not significant

N.S.

60

N.S.

N.S.

59.1
55.8

50

54.6
52.0

51.6

52.6

51.7

51.1

40
PreSSCC

SSC30

SSC last10

PostSSC

SSC with MSAF Group (N=9)

Changes in Temperature

SSC with clear AF Group (N=12)38.0
N.S.:not significant
N.S.

N.S.

N.S.

N.S.

）

37.5

37.3
37.0

T

37.1

36.7

36.5

37.0

36.9

36.9

36.9
36.8

36.0

PreSSC

SSC30

SSC last10

PostSSC

Fig. 6 Changes in physiological indices for PreSSC, SSC30, SSClast10, and PostSSC (Study B)
A : Changes in heart rate B : Changes in respiratory rate C : Changes in temperature
Data are presented as mean±SD.
PreSSC represents data measured for 5 min prior to commencing SSC, SSC30 represents data measured
for 10 min at 25-30 min after commencing SSC, SSClast10 represents data measured for 10 min prior tocompletion of SSC, PostSSC represents data measured for 10 min after completion of SSC.
100

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SSC : autonomic nervous system changes
pre-ductalA

post-ductal
100
95

SpO2(%)

90
85
80
75
70
65

SSC

60
0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 3

00 105 110 115 120

Minutes after birthpre-ductal
post-ductal

B

100
95
90

SpO2(%)

85
80
75
70
65

SSC

60
0

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 2

00 105 110 115 120

Minutes after birthFig. 7

Neonatal pre- and post-ductal SpO2 levels during 2h after birth (Study B)
A : SSC with MSAF Group B : SSC with clear AF GroupIt shows every 1 min for 30 min, and every 5 min for 2h. Data are presented as mean±SD.
SSC was commenced at 32.0±12.1(A) ; 23.5±12.7(B) min after birth and was conducted for 64.2±15.3 (A); 73.8±9.2(B) min

raising effect of SSC was confirmed in this study.

no significant difference between the groups. ThisThe accurate temperature of infants is approximate-result is comparable with that of a report21） indicat-

ly 37 ℃19）, and SSC may help in maintaining thising that in infants who do not require resuscitation,

temperature.

10 min is required to reach 90 ％ oxygenation (meet-

In the SSC group, SSC was commenced after SpO2

ing the target time for SpO2 to reach ＞90 ％ in neo-reached at least 90 ％ ; however, except for one mo-

natal cardiopulmonary resuscitation). Moreover, thement during SSC, SpO2 shifted to within the normal

time taken for SpO2 to reach 90 ％ was slower for

range of ＞ 95 ％ . Although early postpartum

post-ductal than for pre-ductal, irrespective of themother-infant separation has been reported topresence/absence of SSC, and postpartum observa-

20）

interfere with arterial blood oxygenation , we foundtion while monitoring pre-ductal SpO2 is important.

no such indication in our study. Moreover, pre-

SSC increases the state of sleep in infants, sup-ductal SpO2 reached 90 ％ after 10 min in the SSC

presses SNS activity 2h after birth, and increases

group and after 7 min in the non-SSC group, withtemperature. The results indicated that SSC is effec-

No. 2, 2019101

Haga・Tokutake・Sakaguchi et al.

tive in inducing a state of rest at birth and in pre-logical indices are stable during SSC, irrespective ofventing hypothermia.

the presence /absence of MSAF.

B

Next, upon examining SpO2, no significant differ-Study B : Influence of MSAF
Complications in the event of severe MSAF in-ence was found in the time taken for the pre-ductal

clude non-reassuring fetal status, meconium aspira-SpO2 to reach 90 ％ according to the presence/ab-tion syndrome, and persistent pulmonary hyperten-

sence of MSAF. Moreover, SpO2 during SSC shifted22）

sion of the newborn (PPHN) . A report indicatedto almost ＞ 95 ％ in most neonates irrespective ofthat when abnormalities are observed on fetal heart

the presence/absence of MSAF, suggesting thatrate monitoring and MSAF occur simultaneously,

postpartum oxygenation does not differ according to

the number of infants with acidosis and who require

the presence/absence of MSAF. Moreover, no signif-

23）

resuscitation increases . In our study, we examined

icant difference was found in Apgar scores or umbil-changes in ANS and physiological indices according

ical arterial blood pH according to the presence/

to the presence/absence of MSAF in term infantsabsence of MSAF.

who received SSC following vaginal delivery. The

Therefore, when performing SSC, it is still import-mean time to SSC commencement was not signifi-

ant to monitor the neonate with an attached pulse

cantly different according to the presence/absence

oximeter and medical staff. In addition, for early de-of MSAF, and therefore, even in the presence oftection of PPHN, monitoring of the SpO2 of the pre-MSAF, if the indications are satisfied, SSC can be

and post-ductal is essential.

commenced at the same time as in the absence ofMSAF.

SSC increases the success rate of breastfeeding
and promotes parent-infant bonding. Monitoring andWith regards to the ANS, for both LF/HF andcareful observation are essential for safely imple-

HFnu, no significant differences were found at any

menting SSC with the recognition of postpartumof the time points according to the presence/absence

instability in an infant, in accordance with the “Pointsof MSAF. Therefore, when the indications for SSC

to Bear in Mind in Regards to the Implementation ofare satisfied, changes in ANS are comparable in the

Early Mother-Infant Skin-to-Skin Contact.”

presence/absence of MSAF.

Acknowledgements

We observed no significant differences according
to the presence/absence of MSAF in the physiologi-

We were grateful to all the mothers-infants who

cal indices (HR, RR, and temperature), and we foundparticipated in this study. The study was supported

no significant differences in the shifts in these indi-by JSPS KAKENHI Grant Numbers JP21792254,

ces from prior to commencing SSC to after having

JP16K12138.

completed SSC. Accordingly, our results indicatedConflict of Interest

that if SSC is commenced after careful observation
until the infant satisfies the indications, the physio-

There are no conflicts of interest to declare.

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