RESEARCH ARTICLE
Associa ion o objec i ely measu ed physical
i ness du ing p egnancy wi h ma e nal and
neona al ou comes. The GESTAFIT P ojec
Lau a Baena-Ga cı
´a
1☯
, I ene Coll-RiscoID
2,3☯
*, Olga Oco
´n-He na
´ndez
4
, Lidia Rome o-
Galla do
3,4,5
, Ped o Acos a-Manzano
3,4,5
, Linda May
6
, Vi ginia A. Apa icio
2,3
1Depa men o Nu sing, Facul y o Heal h Sciences, Uni e si y o G anada, G anada, Spain, 2Depa men
o Physiology, "Jose
´Ma aix Ve du
´" Ins i u e o Nu i ion and Food Technology (INYTA) and Biomedical
Resea ch Cen e (CIBM), Uni e si y o G anada, G anada, Spain, 3Spo and Heal h Uni e si y Resea ch
Ins i u e (iMUDS), Uni e si y o G anada, G anada, Spain, 4UGC o Gynaecology and Obs e ics, “San
Cecilio” Uni e si y Hospi al, G anada, Spain, 5Depa men o Physical Educa ion and Spo s, Facul y o
Spo Sciences, Uni e si y o G anada, G anada, Spain, 6Depa men o Founda ional Science and
Resea ch, School o Den al Medicine, Eas Ca olina Uni e si y, G een ille, NC, Uni ed S a es o Ame ica
☯These au ho s con ibu ed equally o his wo k.
*[email p o ec ed]
Abs ac
Aim
To analyse i) he associa ion o physical i ness du ing ea ly second imes e and la e p eg-
nancy wi h ma e nal and neona al ou comes; and ii) o in es iga e whe he physical i ness
is associa ed wi h he ype o bi h ( aginal o caesa ean sec ion).
Me hods
P egnan women om he GESTAFIT P ojec (n = 159) pa icipa ed in his longi udinal
s udy. Ma e nal physical i ness including uppe - and lowe -body s eng h, ca dio espi a o y
i ness (CRF) and lexibili y we e measu ed h ough objec i e physical i ness es s a he
16
h
and 34
h
ges a ional weeks. Ma e nal and neona al ou comes we e collec ed om
obs e ic medical eco ds. Umbilical a e ial and enous blood gas pH and pa ial p essu e
o ca bon dioxide (PCO
2
) and oxygen (PO
2
), we e assessed.
Resul s
A he 16
h
week, g ea e uppe -body muscle s eng h was associa ed wi h g ea e neona al
bi h weigh ( = 0.191, p<0.05). Ma e nal lexibili y was associa ed wi h a mo e alkaline a e-
ial pH ( = 0.220, p<0.05), highe a e ial PO
2
( = 0.237, p<0.05) and lowe a e ial PCO
2
( = -0.331, p<0.01) in umbilical co d blood. Ma e nal CRF a he 16
h
ges a ional week was
ela ed o highe a e ial umbilical co d PO
2
( = 0.267, p<0.05). The women who had cae-
sa ean sec ions had lowe CRF (p<0.001) a he 16
h
ges a ional week and wo se clus e ed
o e all physical i ness, bo h a he 16
h
(-0.227, p = 0.003, con idence in e al (CI): -0.376,
-0.078) and 34
h
ges a ional week (-0.223; p = 0.018; CI: -0.432, -0.015) compa ed wi h he
women who had aginal bi hs.
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 1 / 18
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OPEN ACCESS
Ci a ion: Baena-Ga cı
´a L, Coll-Risco I, Oco
´n-
He na
´ndez O, Rome o-Galla do L, Acos a-Manzano
P, May L, e al. (2020) Associa ion o objec i ely
measu ed physical i ness du ing p egnancy wi h
ma e nal and neona al ou comes. The GESTAFIT
P ojec . PLoS ONE 15(2): e0229079. h ps://doi.
o g/10.1371/jou nal.pone.0229079
Edi o : Zhong-Cheng Luo, Moun Sinai Heal h
Sys em, Uni e si y o To on o, CANADA
Recei ed: May 14, 2019
Accep ed: Janua y 29, 2020
Published: Feb ua y 18, 2020
Copy igh : ©2020 Baena-Ga cı
´a e al. This is an
open access a icle dis ibu ed unde he e ms o
he C ea i e Commons A ibu ion License, which
pe mi s un es ic ed use, dis ibu ion, and
ep oduc ion in any medium, p o ided he o iginal
au ho and sou ce a e c edi ed.
Da a A ailabili y S a emen : All ele an da a a e
wi hin he manusc ip and i s Suppo ing
In o ma ion iles.
Funding: This s udy was pa o VAA ellowship
om he Andalucı
´a Talen -Hub P og am, launched
by he Andalusian Knowledge Agency, co- unded
by he Eu opean Union’s Se en h F amewo k
P og am, Ma ie Skłodowska-Cu ie ac ions
(COFUND–G an Ag eemen nº291780) and he
Jun a de Andalucı
´a. ICR (g an numbe : FPU13/
Conclusion
Inc easing physical i ness du ing p egnancy may p omo e be e neona al ou comes and is
associa ed wi h a dec ease in he isk o caesa ean sec ion.
This ial was egis e ed a ClinicalT ials.go (NCT02582567) on Oc obe 20, 2015.
In oduc ion
Resea ch con inues o con i m ha exe cise du ing p egnancy con ibu es o heal hie ou -
comes o bo h he mo he and he e us [1,2]. Consequen ly, exe cise is cu en ly ecom-
mended in all low isk p egnancies [1]. Exe cise du ing p egnancy has been ela ed o an
enhanced e iciency o he placen a [3] and he placen al u e ine pe usion [4], a lowe a e o
caesa ean sec ions [1], and op imal bi h weigh [5]. Imp o ed physical i ness is usually
obse ed in women who exe cise du ing p egnancy [6] and is associa ed wi h be e pe ina al
heal h ou comes [7,8]. Howe e , while i is well-es ablished ha physical ac i i y imp o es
bi h ou comes [9–11], s udies looking a he ela ionships be ween objec i e assessmen s o
i ness and deli e y ype, ges a ional age, du a ion o labou s ages, bi h weigh and alues o
umbilical co d blood gas a e limi ed.
The causes o caesa ean sec ions and how o educe caesa ean sec ion a es a e now a spo -
ligh o esea ch as his ype o deli e y has been associa ed wi h an inc eased isk o in ec ion
compa ed wi h aginal deli e ies, highe wound dehiscence, haemo hage and educed e il-
i y [12–14], as well as an inc eased isk o alle gies, ype 1 diabe es o espi a o y p oblems
[15] in in an s, among o he complica ions. Fu he mo e, i is no ewo hy ha in 2016 in
Spain he e we e 22% caesa ean sec ions in public hospi als [16], highe han he 15% a e ec-
ommended by he Wo ld Heal h O ganiza ion [17]. The e o e, i is o g ea impo ance o
clinical p ac ice o analyse he associa ions be ween ma e nal a iables and imp o emen s in
he a es o caesa ean sec ions.
Du ing p egnancy, u e ine blood low is c ucial o app op ia e nu ien and gas exchange
wi h he e us [18]. I is widely known ha he umbilical co d blood pH analysis p o ides i al
in o ma ion abou neona al heal h s a us and e lec s physiological esponse o complica ions
ha may occu du ing labou [19]. We p e iously ound ha highe le els o ligh o mode a e
physical ac i i y du ing p egnancy we e associa ed wi h g ea e umbilical a e ial oxygen sa u-
a ion and highe le els o enous co d blood pH; con e sely, we showed ha highe le els o
seden a y ime du ing p egnancy we e ela ed o wo se p egnancy ou comes [10]. Howe e , i
is unknown whe he ma e nal physical i ness is also a key ac o o imp o e bi h ou comes
such as ges a ional age, du a ion o labou , bi h weigh and alues o umbilical co d blood
gas. This s udy highligh s he impo ance o app opia e le els and quali y o i ness ha should
be emphazised in exe cise p og ams in o de o imp o e bi h ou comes. Fu he mo e, he
associa ion o ma e nal physical i ness wi h e al acid-base balance has no been s udied. The
measu emen o gases in he umbilical co d blood is a gold s anda d in he de e mina ion o
he oe al acid-base balance [20]. In addi ion, he de e mina ion o PCO
2
is impo an , since
highe le els o PCO
2
and a low pH le el indica e a s a e o e al acidosis [19,21]. On he o he
hand, CO
2
p oduc ion is p opo ional o oxygen consump ion [22], so he in e p e a ion o
PO
2
le els and oxygen sa u a ion also p o ides undamen al in o ma ion o de e mine he
e ec i eness o he e al compensa o y mechanisms and he s a e o he placen a. The e o e,
he aims o his s udy we e: i) o analyse he associa ion o ma e nal physical- i ness measu es
du ing he ea ly second imes e and la e p egnancy wi h ma e nal (ges a ional age a bi h
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 2 / 18
01993) was suppo ed by he Spanish Minis y o
Educa ion. This s udy was also pa ially unded by
he Regional Minis y o Heal h o he Jun a de
Andalucı
´a (PI-0395-2016) and he Uni e si y o
G anada, Plan P opio de In es igacio
´n 2016,
Excellence ac ions: Uni s o Excellence; Uni o
Excellence on Exe cise and Heal h (UCEES). The
unde s had no ole in s udy design, da a collec ion
and analysis, decision o publish, o p epa a ion o
he manusc ip .
Compe ing in e es s: The au ho s ha e decla ed
ha no compe ing in e es s exis .
and leng h o he i s and second s ages o labou ) and neona al (bi h weigh and umbilical
co d blood gas alues) ou comes; ii) o in es iga e whe he ma e nal physical- i ness du ing
he ea ly second imes e and la e p egnancy may in luence he ype o bi h (i.e. aginal o
caesa ean sec ion). Acco dingly, we hypo hesized ha ma e nal physical- i ness may be posi-
i ely associa ed wi h imp o ed ma e nal and neona al ou comes. The aim o he s udy was o
be e unde s and he in luence o ma e nal i ness du ing p egnancy on ma e nal and neona-
al ou comes.
Ma e ials and me hods
S udy popula ion
The de ailed p ocedu es, inclusion and exclusion c i e ia (S1 Table) o he GESTA ion and
FITness (GESTAFIT) P ojec we e published elsewhe e [23]. Ini ially, his s udy was based on
a andomized con ol ial design, ha was modi ied in o de o ensu e e en ion o women in
he con ol g oup. Thus, women we e alloca ed ei he o an exe cise o a con ol g oup
depending on hei pe sonal p e e ence and con enience o a end he in e en ion sessions
and he wa e hey had been ec ui ed o . In his way, high d opou a es we e a oided, which
is one o he mos equen me hodological ba ie s in an ena al exe cise esea ch, as p e i-
ously a gued [24]. B ie ly, he in e en ion g oup unde wen a supe ised ae obic and s eng h
aining in e en ion om he 17
h
ges a ional week un il deli e y. A o al o 384 p egnan
women we e in o med abou he P ojec du ing hei 12
h
ges a ional week isi o he obs e i-
cian a he “San Cecilio” Uni e si y Hospi al and “Vi gen de las Nie es” Uni e si y Hospi al
(G anada, sou he n Spain). A inal numbe o 159 women we e in e es ed in pa icipa ing and
signed an in o med consen . The GESTAFIT s udy was app o ed by he E hics Commi ee on
Clinical Resea ch o G anada, Go e nmen o Andalusia, Spain (code: GESTAFIT-0448-N-15,
app o ed on 19/05/2015).
P ocedu es
The i s e alua ion o he s udy was comple ed a he 16
h
week o ges a ion (±2 weeks).
Women comple ed a sel - epo ed ques ionnai e, an an h opome ic assessmen , and physical
i ness es s. On he 34
h
week o ges a ion (±2 weeks), he second assessmen o physical i ness
es s and heigh and weigh was conduc ed. Bi h and obs e ic ou comes o he cu en p eg-
nancy we e collec ed om he digi al medical eco ds ( he p egnancy heal h documen and
he pa og am). Sampling o he umbilical co d occu ed 3 minu es a e bi h.
Measu emen s
Ma e nal sociodemog aphic da a. Sociodemog aphic da a (age, numbe o child en;
ma i al, educa ional and wo king s a us) we e assessed wi h a sel - epo ed ques ionnai e. A
esea ch s a was p esen a all imes o any needed explana ion o ins uc ion.
Ma e nal an h opome ic assessmen . Heigh and weigh we e measu ed using a s adi-
ome e (Seca 22, Hambu g) and a scale (InBody R20; Biospace, Seoul, Ko ea), espec i ely.
Body mass index was calcula ed as: weigh (Kg)/heigh (m
2
).
P egnancy heal h. The “P egnancy Heal h Documen ” (Ca illa del emba azo in Spanish)
is gi en o all p egnan women by he Andalusian egional go e nmen , and i con ains obs e -
ic and medical da a eco ded du ing all he leng h o he p egnancy and we e collec ed o he
p esen s udy. In his way, in o ma ion abou p e ious p egnancies, bi hs, and gynaecological
an eceden s we e ob ained. The ges a ional age was calcula ed by he da e o he las mens ua-
ion co ec ed o cycles o 28 days and subsequen ly co ec ed by ul asound, i needed [25],
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 3 / 18
and was used o an accu a e iming o he e alua ions a he 16
h
and he 34
h
weeks o
p egnancy.
Bi h ou comes. All da a ela ed o he ype o bi h (spon aneous aginal, ins umen al
o caesa ean), ges a ional week a bi h, use o epidu al analgesia, leng h o each s age o
labou , o sp ing sex, neona al weigh and Apga es we e ob ained om pe ina al obs e ic
eco ds (pa og am) om he Hospi al a e bi h. The cause (unplanned o planned, and
whe he i was elec ed o physiological easons) o caesa ean sec ions was anno a ed. We only
had access o he pa og ams and samples o women who ga e bi h in he Public Hospi als
app o ed by he E hics Commi ee. Howe e , he ype o deli e y was eco ded o all women.
The placen a was collec ed immedia ely a e he deli e y and he placen al su ace clo s
we e emo ed. The amnion was cu om he basal a ea and he umbilical co d was comple ely
cu . Subsequen ly, placen a was weigh ed wi h a 3.200 kg P ecision G am Scale (Ohaus Com-
pass
TM
, USA).
Umbilical co d blood gas. Fo he umbilical co d blood sampling, a ained midwi e pe -
o med a double clamping o he umbilical co d h ee minu es a e bi h, wi h a minimum
dis ance be ween bo h clamps o 10 cen ime es. A p e-hepa inized 1mL sy inge was used o
blood ex ac ion. Blood samples we e aken om bo h, umbilical a e y and ein. Pa ial p es-
su e o ca bon dioxide (PCO2), pa ial p essu e o oxygen (PO2), oxygen sa u a ion and pH
we e analysed using a blood analyse (GEM P emie 4000; Ins umen a ion Labo a o y, Bed-
o d, MA, USA).
Physical i ness. Physical i ness was assessed in he ollowing o de o a oid po en ially
induced a igue om o he es s:
Uppe -body muscula s eng h. Hand g ip s eng h was measu ed wi h digi al dynamome y
(TKK 5101 G ip-D; Takey, Tokyo, Japan) a e adjus ing o he hand size o an op imal g ip
[26]. The es was pe o med wice wi h bo h hands, wi h a es o 30 seconds and al e na ing
hands. The inal alue was calcula ed as a mean o he wo alues om each hand.
Lowe -body muscula s eng h. Muscula s eng h o he lowe -body was measu ed h ough
he 30-second Chai S and es . This es coun s he maximum numbe o epe i ions com-
ple ed in 30 seconds, wi h a ull s and o a si ing posi ion and back s aigh up as one epi i-
ion. The pa icipan s pe o med one ial a e a amilia iza ion ial [27].
Flexibili y.The Back Sc a ch es was used o assess uppe -body lexibili y. The es consis s in
measu ing he o e all shoulde ange o mo ion by measu ing he dis ance be ween he middle
inge s coming oge he behind he back. The Back Sc a ch es ou come is posi i e o highe lex-
ibili y (i.e. hands o e lapping behind he back) and nega i e o lowe lexibili y (i.e. g ea e dis-
ance be ween middle inge s behind he back). This es was done wice wi h bo h hands and he
inal sco e was calcula ed as he mean be ween he wo a emp s o each a m [27].
Ca dio espi a o y i ness. Maximal oxygen in ake (VO
2max
) was es ima ed (ml/Kg/min)
h ough he Modi ied B uce eadmill p o ocol [28], a submaximal, inc emen al, mul is age,
con inuous eadmill es . The es consis s o p og essi e inc emen s in he wo kload and
eloci y e e y 3 minu es o de e mine limi s o maximal exe ion. Women we e asked o walk
on he eadmill du ing he es un il he ma e nal hea a e eached 75% o he age-p edic ed
maximal hea a e; i he pa icipan eques ed o end he eadmill es , hen he es was also
s opped be o e eaching he hea a e alue. Al hough submaximal eadmill es ing is com-
mon and sa e du ing p egnancy, women we e secu ed wi h a ha ness du ing he es o p e en
any consequences om a all. This es has been p e iously used and shown o be sa e in p eg-
nan women [28,29].
S a is ical analyses. We employed desc ip i e s a is ics [mean (s anda d de ia ion, SD)]
o quan i a i e a iables and numbe o cases and pe cen age (%) o ca ego ical a iables. All
he a iables we e checked o no mali y o dis ibu ion h ough ku osis and skewness
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 4 / 18
analyses be o e he analyses. All he ou come a iables easonably me his assump ion. The
associa ions o physical i ness le els wi h ma e nal (ges a ional age a bi h and leng h o he
i s and second s ages o labou ) and neona al (bi h weigh and umbilical co d blood gas al-
ues) ou comes we e assessed wi h pa ial co ela ions a e adjus ing o ma e nal age, pa i y
and BMI (Table 2). The associa ions o physical i ness le els wi h du a ion o he i s and sec-
ond labou s ages, as well as neona al ou comes we e also adjus ed o epidu al analgesia,
excep o he a iable “bi h weigh ” which was only u he adjus ed o ges a ional age. Since
some a iables (ges a ional age a bi h, bi h weigh , du a ion o he i s and second s ages o
labo and ins umen al deli e y) p e iously showed weak associa ions wi h ou come a iables
(p>0.02), we pe o med seconda y analyses o assess hei ole as po en ial con ounde s.
Changes be ween p e (16
h
week) and pos (34
h
week) e alua ions esul s o i ness es s
we e analysed ia epea ed measu es T-Tes s (S2 Table). Subsequen ly, he changes (pos –p e)
we e included in he linea eg ession analyses (Table 3) as p edic o a iables, whe eas he
bi h ou comes we e included as ou come a iables in sepa a e models. Rele an con ounde s
sugges ed by p e ious li e a u e wi h signi ican ela ionship wi h he ou comes, ha in lu-
enced he ela ionship be ween he independen and dependen a iable (i.e. B o he indepen-
den had a meaning ul change (p>0.05) when adding he a iable), we e included in he
models. Depending on he aim o he analysis, he models we e adjus ed o none con ounde ,
o baseline alues o ca dio espi a o y i ness (CRF), o o baseline alues, age, pa i y, weigh
change (pos –p e), and exe cise in e en ion (only a he 34
h
-week analysis). The a iables
showing he du a ion o he i s and second labou s ages, as well as neona al bi h ou comes
we e addi ionally adjus ed o epidu al analgesia (as independen a iable), excep o he a i-
able “bi h weigh ” which was only u he adjus ed o ges a ional age.
Logis ic eg ession analysis was also employed o explo e he associa ions be ween physical
i ness le els (p edic o a iable) and he chances o ha ing a aginal deli e y (spon aneous
and ins umen al) o caesa ean sec ion (ou come a iable) (Table 4). We adjus ed he analysis
o he abo e-men ioned co a ia es. We also conside ed “place o bi h” as a po en ial con-
ounde due o he di e ences o caesa ean sec ion a ios be ween p i a e and public hospi als
in Spain [30]. Hence, we decided o check wi h he Chi-squa ed es i he ype o hospi al
migh ha e any in luence on ou come a iables. Gi en ha we ound s a is ically signi ican
di e ences in bi h ou comes be ween p i a e and public hospi als wi hin ou da a, we decided
o include his a iable as a po en ial con ounde .
Finally, in he GESTAFIT p ojec [23], a concu en physical exe cise p og am was pe o med.
We ha e also adjus ed all he models o he exe cise in e en ion (con ol o in e en ion).
We c ea ed a clus e ed o e all physical i ness (Z-sco e) as he mean o he s anda dized sco es
[( alue–mean)/ s anda d de ia ion] o body s eng h (mean o uppe and lowe - body s eng h
s anda dized alues), lexibili y and CRF a he 16
h
week o p egnancy (Fig 2A) and he 34
h
week
o p egnancy (Fig 2B). Bo h clus e ed g oups we e compa ed by caesa ean o aginal deli e y
wi h an ANCOVA analysis. We adjus ed he analysis o ma e nal age, pa i y, ma e nal BMI a
he 16
h
ges a ional week, exe cise in e en ion and bi h place (public o p i a e hospi al).
The s a is ical analyses we e conduc ed wi h he S a is ical Package o Social Sciences (IBM
SPSS S a is ics o Windows, Ve sion 20.0. A monk, NY: IBM Co p). The s a is ical signi i-
cance was se a p<0.05.
Resul s
O all he 159 pa icipan s, 158 had comple e sociodemog aphic da a (Fig 1). The inal sample
size was composed o 158 Caucasian p egnan women (age 32.9±4.6 yea s, BMI 24.9±4.1 kg/
m
2
) wi h alid da a o he p esen analyses. A he 16
h
and 34
h
weeks o p egnancy, 156 and
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 5 / 18

Fig 1. Flowcha in he selec ion o s udy pa icipan s o speci ic s udy aims.
h ps://doi.o g/10.1371/jou nal.pone.0229079.g001
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 6 / 18
124 women pa icipa ed in he physical i ness es s (Fig 1). A o al o 18 pa og ams we e no
ound in he in o ma ic sys em (n = 9) o could no be collec ed as some pa icipan s deli e ed
in a p i a e hospi al no associa ed wi h he s udy (n = 9) and pa og ams could no be
accessed, nei he could he samples o placen a be collec ed. Howe e , he ype o deli e y was
eco ded o he deli e ies in p i a e hospi als. Hence, a o al o 141 women had comple e
alid da a o bi h ou comes.
The sociodemog aphic and clinical cha ac e is ics o he s udy pa icipan s a e shown in
Table 1. Mos o he pa icipan s li ed wi h hei pa ne and mo e han hal had Uni e si y
educa ion and wo ked ull ime. App oxima ely 61% o he sample we e nullipa ous and
75.6% had aginal bi hs. Bi hs ook place a ound 39.5±1.3 weeks o ges a ion, wi h a mean
neona e body weigh o 3305±480.6 g ams. A he 16
h
and 34
h
ges a ional weeks, mean alues
we e simila in uppe -body s eng h (Hand g ip); lowe -body s eng h (Chai s and); and 4.1
±6.2 cm and 3.9±6 cm in lexibili y es (Back Sc a ch) (all, p>0.05), bu dec eased in CRF 22.1
±5.5 ml/Kg/min and 17.9±4.9 ml/Kg/min (p<0.001) (Modi ied B uce eadmill es ). All
umbilical co d blood gas mean alues we e wi hin no mal anges.
Pea son’s pa ial co ela ions o physical i ness le els a he 16
h
and he 34
h
ges a ional weeks
wi h ma e nal and neona al ou comes a e shown in Table 2.Rega ding he ma e nal ou comes,
physical i ness le els we e no associa ed wi h hese measu es. In ela ion o neona al ou comes,
uppe -body muscle s eng h a he 16
h
week o ges a ion was associa ed wi h highe bi h weigh
( = 0.191, p<0.05). Lowe -body muscle s eng h was no associa ed wi h any ma e nal and neo-
na al ou come (p>0.05). G ea e ma e nal lexibili y a he 16
h
week was associa ed wi h a mo e
alkaline pH ( = 0.220, p<0.05), highe PO
2
( = 0.237, p<0.05), highe a e ial oxygen sa u a ion
( = 0.242, p<0.05), and lowe PCO
2
( = -0.331, p<0.01) in a e ial umbilical co d blood. Ma e -
nal CRF a he 16
h
week was ela ed o highe PO
2
( = 0.267, p<0.05) and highe oxygen sa u a-
ion ( = 0.375, p<0.01) in a e ial umbilical co d blood. Physical i ness le els a he 34
h
week o
p egnancy we e no associa ed wi h any ma e nal and neona al bi h ou comes (all, p>0.05).
S2 Table, compa ing he i ness le els a he 16
h
and he 34
h
weeks o ges a ion, he e we e
no di e ences in lexibili y, uppe - o lowe -body s eng h be ween he di e en ime poin s.
CRF dec eased by 4.14 (5.07) ml/kg/min om he 16
h
o he 34
h
weeks o ges a ion (95% CI:
3.01, 5.27; p<0.001).
The associa ions o he changes in CRF wi h bi h ou comes a e shown in Table 3. A e ial
co d blood PO
2
and O
2
sa u a ion we e in e sely associa ed wi h he CRF change (B = -0.603;
95% CI: -1.101, -0.105; p = 0.019, and B = -1.544; 95% CI: -2.720, -0.368; p = 0.011, espec i ely),
wi h simila esul s in he model adjus ed o baseline CRF, age, pa i y, weigh change and exe cise
in e en ion. The model adjus ed only o baseline alues o CRF showed an in e se associa ion
be ween CRF change and a e ial co d blood PO
2
(B = -0.622; 95% CI: -1.221, -0.023; p = 0.042).
Di e ences in physical i ness le els a he 16
h
and 34
h
ges a ional weeks by bi h ype
( aginal o caesa ean sec ion) a e shown in Table 4. A he 16
h
week o p egnancy, no signi i-
can di e ences we e ound in uppe - and lowe -body muscle s eng h be ween women who
had aginal bi hs compa ed wi h women who had caesa ean sec ions (bo h, p>0.05). The
mean o lexibili y le els was +2.4 (4.7) cm in he Back Sc a ch es in women who had caesa -
ean sec ions compa ed wi h +5.0 (6.2) cm in women who had aginal bi hs (95% CI -0.027,
-0.020; p= 0.027). Finally, women who had caesa ean sec ions had a mean o CRF o 18.4 (4.2)
ml/kg/min in he Modi ied B uce es compa ed wi h women wi h a aginal bi h who had
23.3 (5.7) ml/kg/min in CRF (95% CI: -0.035, -0.009; p = 0.001). Fo physical i ness a he 34
h
week o ges a ion, lexibili y was highe in women who had aginal bi hs wi h 4.9 (6.0) cm,
han in women wi h caesa ean sec ion, 1.0 (5.8) cm (95% CI: 0.027, 0.001; p = 0.033).
Fig 2A and Fig 2B show he clus e ed o e all physical i ness a he 16
h
and 34
h
weeks o
ges a ion, espec i ely. Rela i e o women who had aginal bi hs, women who had caesa ean
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 7 / 18
Fig 2.
h ps://doi.o g/10.1371/jou nal.pone.0229079.g002
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
PLOS ONE | h ps://doi.o g/10.1371/jou nal.pone.0229079 Feb ua y 18, 2020 8 / 18
Table 1. Sociodemog aphic and clinical cha ac e is ics o he s udy sample (n = 158).
Ma e nal cha ac e is ics n Mean (SD)
Age, yea s 158 32.9 (4.6)
Body mass index a he 16
h
ges a ional week, Kg/m
2
158 24.9 (4.1)
Body mass index a he 34
h
ges a ional week, Kg/m
2
158 27.8 (4.1)
Weigh a he 16
h
ges a ional week, Kg 157 67.04 (11.8)
Weigh a he 34
h
ges a ional week, Kg 123 74.57 (10.8)
Weigh change ( om he 16
h
o he 34
h
ges a ional weeks) 121 8.7 (3.4)
E hnici y (Caucasian) 158 158 (100)
n (%)
Li ing wi h a pa ne , 154 (97.5)
Educa ional s a us 158
P ima y o high-school 37 (23.4)
Specialized aining 27 (17.1)
Uni e si y deg ee 94 (59.5)
Wo king s a us 158
Homewo k/unemployed 48 (30.4)
Pa ial- ime employed/s uden 41 (25.9)
Full- ime employed 69 (43.7)
Type o bi h 143
Spon aneous 83 (58)
Ins umen al acuum/ o ceps 24 (16.8)
Caesa ean sec ion 36 (25.5)
Planned ( ee o bu ocks coming i s ) 7 (27.5)
Bi h place 147
Public Hospi al 138 (93.9)
P i a e Hospi al 8 (5.4)
Home 1 (0.7)
Pa i y 158
Nullipa ous 96 (60.8)
Mul ipa ous 62 (39.2)
Physical i ness a he 16
h
ges a ional week Mean (SD)
Uppe -body s eng h (Hand g ip),mean (Kg) 156 27.2 (4.2)
Lowe -body s eng h (Chai s and),numbe o epe i ions 93 15.7 (2.4)
Flexibili y (Back Sc a ch),mean (cm) 156 4.1 (6.2)
CRF (Modi ied B uce es ),VO
2max
127 22.2 (5.5)
Physical i ness a he 34
h
ges a ional week
Uppe -body s eng h (Hand g ip),mean (Kg) 124 27.2 (4.4)
Lowe -body s eng h (Chai s and),numbe o epe i ions 65 15.9 (2.5)
Flexibili y (Back Sc a ch),mean (cm) 123 3.9 (6)
CRF (Modi ied B uce es ),VO
2max
97 17.9 (4.9)
Neona al ou comes
Sex ( emale, n (%)) 141 72 (51.4)
Ges a ional age a bi h, wk 141 39.5 (1.3)
Bi h weigh , g ams 141 3305 (480.6)
Placen al weigh , g ams 106 573.7 (102.6)
Apga sco e 1 minu e 138 8.6 (1)
Apga sco e 5 minu es 138 9.6 (0.7)
Umbilical Co d blood Gas
(Con inued)
Associa ion o physical i ness and ma e nal and neona al bi h ou comes
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