Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on https://www.journals.elsevier.com/brazilian-journal-of-physical-therapy
Brazilian
Journal
of
Physical
Therapy
ORIGINAL
RESEARCH
Exercise
during
pregnancy
has
a
preventative
effect
on
excessive
maternal
weight
gain
and
gestational
diabetes.
A
randomized
controlled
trial
夽
,
夽夽
Ruben
Barakat
a,∗,
Ignacio
Refoyo
a,
Javier
Coteron
a,
Evelia
Franco
baAFIPEResearchGroup,TechnicalUniversityofMadrid,Madrid,Spain bUniversidadPontificiadeComillas,Madrid,Spain
Received9May2018;receivedinrevisedform29October2018;accepted6November2018
KEYWORDS
Exercise; Physicaltherapy; Pregnancy; Weightgain; Gestationaldiabetes
Abstract
Background: Excessivegestationalweightgainisassociated withseveraladverseeventsand pathologiesduringpregnancy.
Objective: Thepurposeofthisstudywastoexaminetheeffectsofanexerciseprogram through-outpregnancyonmaternalweightgainandprevalenceofgestationaldiabetes.
Method: A randomizedcontrolled trialwas designed thatincludedanexerciseintervention group(EG)andstandardcarecontrolgroup(CG).Theexerciseinterventionincludedmoderate aerobicexerciseperformedthreedaysperweek(50---55minutespersession)for8---10weeksto 38---39weeksgestation.
Results:594pregnantwomenwereassessedforeligibilityand456wereincluded(EGn=234; CGn=222).Theresultsshowedahigherpercentageofpregnantwomengainedexcessiveweight intheCGthanintheEG(30.2%vs20.5%respectively;oddsratio,0.597;95%confidence inter-val,0.389---0.916;p=0.018).Similarly,theprevalenceofgestationaldiabeteswassignificantly higherintheCG thantheEG (6.8%vs 2.6%respectively;oddsratio,0.363; 95%confidence interval,0.138---0.953;p=0.033).
Conclusion: Theresultsofthistrialindicatethatexercisethroughoutpregnancycanreduce theriskofexcessivematernalweightgainandgestationaldiabetes.
©2018Associac¸˜aoBrasileiradePesquisaeP´os-Graduac¸˜aoemFisioterapia.PublishedbyElsevier EditoraLtda.Allrightsreserved.
夽 ThispaperispartofaSpecialIssueonWomen’sHealthPhysicalTherapy.
夽夽TrialIdentifier:NCT02109588.https://clinicaltrials.gov/ct2/show/NCT02109588
∗Correspondingauthorat:MartínFierro7,28040Madrid,Spain.
E-mail:[email protected](R.Barakat).
https://doi.org/10.1016/j.bjpt.2018.11.005
Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on
Introduction
Pregnancy and delivery are biological processes that can haveasignificantimpactonmaternalhealth andnewborn wellbeing.Researchhasshownthateventsthatoccur dur-ingpregnancymayinfluencebothmaternalandfetalfuture healthoutcomes.1,2
The impact that gestational weight gain can have on healthoutcomeshasbeenespeciallyrecognizedbyhealth care professionals as a potential factor that may influ-ence maternal and fetal wellbeing. Excessive gestational weightgainis associatedwithseveral adverse eventsand pathologies.Many studies reportcomplications related to thewellbeingof the mother,fetusand eventhenewborn andinfantduetoinappropriatematernalweightgainduring pregnancy.3---8
Gestational diabetes mellitus (GDM) is defined as ‘‘carbohydrate intolerancewith onset or first recognition duringpregnancy’’9anditisamongmanyproblemsthatare highlyrelatedtoexcessivematernalweightgain.10 Indeed theprevalence ofGDMis increasingin parallelwith over-weightandobesityintheobstetricpopulation.11,12Current trendsfor weightgain amongwomen ofreproductive age arealarming.13,14
Precise estimates of GDM prevalence are not clear. A recentmeta-analysisreportedthattheprevalenceofGDM in Europe is 5.4%.15 According to the American Diabetes Association (ADA), GDM complicates approximately 7% of allpregnancies.16 Regardlessofthevariabilitypresentedin availablestudies,datafromwesterncountriessuggeststhat theprevalenceofGDMisincreasing.17---19Womendiagnosed withGDMhaveahigherriskforfuturediabetes,with approx-imately50%ofwomendevelopingtype2diabeteswithin5 yearsofdelivery.20
Manystudies supportthe association of GDM with sev-eraladversematernalandfetaloutcomes.21---23Additionally, therearesomedatathatsuggestanincreaseinfetal mal-formationandperinatalmortality.24---26
Although researchsupports that healthy lifestyle mod-ificationsmayhaveapositiveimpactonmetabolicfactors amongoverweightandobesepregnantwomen,evidencefor specificeffectiveapproachestopreventGDMareneeded.27 Research to identify modifiable factors that might help preventexcessivematernalweightgainandabnormal glu-cose tolerance or GDM, in the pregnant population is neededand hasurgent publichealth importance.28,29 One suchmodifiable factor may beexercise performed during pregnancy.
The existing literature suggests that physical activity before and during pregnancy may be an effective pub-lic health and clinical strategy for GDM prevention and treatment.30 This effectmight beexplainedbythewidely acceptedinfluencethatphysicalactivityhasonpreventing weightgain.31
Research has supported exercise during pregnancy as an effectiveintervention topreventexcessive gestational weightgain.32Furthermore,exerciseduringpregnancyhas been identifiedasan effective approachtocontrol blood sugarstohelppreventandmanageGDM.33Previousstudies carriedoutwithpregnantwomenhoweverhaveconducted physicalactivityprogramsusingsmallsamplesizes and/or lackingsupervision.34,35
Themain aimofthisrandomizedcontrolledtrial(RCT) wastoexaminetheinfluenceofasupervisedexercise pro-gram throughout pregnancy on maternal weight gain and incidenceofGDM.As asecondaryobjective,theeffectof theexerciseprogramonothermaternalandneonatal out-comeswasalsoexamined.Wehypothesizedthatmaternal physical exercisewould beassociatedwithareduction of bothexcessivematernalweightgainandprevalenceofGDM withoutadverseeffectsonothermaternalandnewborn out-comes.
Methods
The present RCT (clinical trial registration number NCT02109588)wasconductedbetweenMarch2014and Jan-uary2017followingtheethicalguidelinesoftheDeclaration of Helsinki, last modified in 2000. The research protocol wasreviewedand approvedbythe HospitalSeveroOchoa (Madrid,Spain) ethics review board (240-09).Participants enrollmentbeganinApril2014.
Participantsandrandomization
A totalof 594 Spanish-speaking (Caucasian)healthy preg-nantwomenfromtwoprimarycaremedicalcenters(Centro
de Salud Los Pedroches, Centro deSalud Leganés Norte,
Madrid, Spain) were recruited during their first prenatal visit(Fig.1).Theywereinformedaboutthenatureofthe study and assessed for eligibility. Women with singleton anduncomplicatedpregnancies(notype1,2orgestational diabetes at baseline), with no history or risk of preterm delivery(i.e.≥1previouspretermdelivery)andnot partici-patinginanyothertrialwereinvitedtoparticipate.Women not planning togive birth in the sameobstetric hospital, or withno medicalfollow-up throughout pregnancy were notincludedinthestudy.Womenhavinganyserious medi-calconditions(contraindications)thatpreventedthemfrom exercisingsafelywerealsonotincluded.36
Acomputer-generatedlistofrandomnumberswasused to allocatethe participants into the study groups follow-ing other previous studies. Allocation ratio was 1:1. The randomizationblindingprocess(sequencegeneration, allo-cationconcealmentandimplementation)wasperformedby threedifferentresearchers.The treatmentallocation sys-temwassetupsothattheresearcherwhowasinchargeof randomlyassigningparticipantstoeachgroupdidnotknow inadvancewhichtreatmentthenextpersonwouldreceive (i.e.concealedallocation).
Women who were randomly allocated to the Exercise Group(EG)receivedsimilarstandardcareandperformedan exerciseprogram throughout pregnancy.Women randomly allocatedtotheControlGroup(CG)receivedobstetric stan-dardcarefromhealthprofessionals.Womenwereexcluded iftheydidnotconformtothespecificationsoftheallotted group.Alltheparticipantssignedaninformedconsent.
Exerciseintervention37,38
Pregnant women in the intervention group received stan-dard care and all aspects of a structured and supervised
Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on
Flow Diagram of study participants
CG Analysed (n=222) EG Analysed (n=234) Final Analysis
Low adherence (n=6)
Premature rupture of the membranes (n=2) Hypertension (n=2)
Persistent bleeding (n=4)
Personal reasons (n=22)
Premature rupture of the membranes (n=5)
Other reasons (n=11) Risk of preterm delivery (n=3) Risk of preterm delivery (n=5) Early abortion (n=4)
Lost to follow-up (n=26) Lost to follow-up (n=38)
Follow-Up
Allocated to control (n=260,control) Allocated to intervention (n=260,exercise) Allocation
Randomized (n=520)
Personal reasons (n=23) Declined to participate (n=20) Not meeting inclusion criteria (n=31) Excluded (n=74)
Assessed for eligibility (n=594) Enrollment
Figure1 Flowchartofstudyparticipants.
moderate exercise intervention program three days per week(55---60minpersession)fromthe8---10thweekof preg-nancy(immediately afterthe firstprenatalultrasound)to theendofthethirdtrimester(weeks38---39).Theexercise protocol wassupervisedby aqualified of physicalactivity and sport science professional (ten years of experience). A total of 83---85 group training sessions were originally planned for each participant in the event of no preterm delivery. The exercise program met the standards of the AmericanCollegeofObstetricians andGynecologists36 and includedthefollowingsevensections:
i. Gradualwarm-up ii. Aerobicexercises
iii. Lightmusclestrengthening iv. Coordinationandbalanceexercises
v. Stretchingexercises
vi. Pelvicfloorstrengthening vii. Relaxationandfinaltalk
Womenusedaheartrate(HR)monitor(AccurexPlus, Fin-land)duringthetrainingsessions(HRwasconsistentlyunder 70%ofage-predictedmaximum)andtheratingofperceived exertionscalerangedfrom12to14(SomewhatHard).39
The exercise session started witha light-intensity, 10-min warm-up consisting of walking and static stretching (avoidingmuscle pain) of most musclegroups (upperand lowerlimbs, neckandtrunkmuscles). Similarly,the exer-cisesessionfinishedwithalight-intensity,10-mincool-down includingthe same exercises as the warm-up period plus relaxation and pelvic floor muscle training. As a motiva-tionalstrategy,afinaltalkwasdonetopromoteextensive counselingandprovideinformationtoensurethatthe parti-cipantsreceivedclearinstructionsonhowtohaveanactive
Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on pregnancyandemphasizingtheimportanceofregular(not
occasional)exercisethroughoutpregnancy.
Themainsectionoftheexercisesessionafterthe warm-upwas30---35mininlengthandincludedmoderate-intensity aerobic exercises and resistance exercises. Aerobic exer-cisesconsistedof low-impactaerobicdance,involvingthe upperandlowerlimbs.Aerobicdanceboutswere approxi-mately3---4minlongandincludedstretchingandrelaxation followedbyaoneminutebreak.
Light muscle strengthening was also included in each session. Strengthening exercises engaged major muscle groups (pectoral, back, shoulder, upper and lower limb muscles) to promote good posture, prevent low back pain and strengthen the muscles used in labor and the pelvic floor (third trimester). Exercises were performed using the full range of motion and involved barbells (3kg/exercise) and low-medium-resistance elastic bands (Therabands). The exercises included biceps curls, arm extensions, arm side lifts, shoulder elevations, bench presses, seated lateral row, lateral leg elevations, leg circles, knee extensions, knee (hamstring) curls, ankle flexionsandextensions.Exercisesinvolvingextreme stretch-ing and joint over-extension, ballistic movements or jumps were avoided, and exercises in the supine posi-tion on the floor were not performed for more than 2min.
As pregnancyprogresses, women mayexperience diffi-cultywithbalancetherefore all coordinationandbalance exercisesconsistedofeasyactivitiesusingsportequipment (foamballs,cords,etc.)forsupport.
Tomaximizeprogramsafety,adherenceandefficacy,all sessionswere:(i)supervisedbyaqualifiedfitnessspecialist (tenyearsofexperience)andwithanobstetrician’s assis-tance;(ii)accompaniedbymusic;and(iii)performedinthe HealthCareCenterinaspacious,well-litroomunder favor-ableenvironmentalconditions(altitude600m;temperature 19---21◦C; humidity 50---60%). An adequate intake of calo-riesandnutrientswasconfirmed beforethestart of each exercisesession.
Theinterventioninvolvedgroupsessionsof12---15 parti-cipants.
Adherence to the training program was ≥80% in the intervention group that was measured by a qualified fit-ness specialist using a checklist of attendance for each session.
Standard-care(CG)
ThewomenassignedtothestandardcareCGattended reg-ular scheduled visits to their obstetricians and midwives (accordingto Hospitalprotocol), usually every 4---5weeks untilthe36---38thweekofgestationandthen weeklyuntil delivery.Theyreceivedgeneralnutritionandphysical activ-itycounselingfromtheirhealth-careprovider.
Women were not discouraged from exercising during pregnancy on their own. However, similar to our previ-ous studies women in the CG were asked about exercise habitsonce each trimester using a ‘‘Decision Algorithm’’ (bytelephone).37
Participantdemographics
Information about demographics, including pre-pregnancy Body Mass Index(BMI), parity,educational level,previous physical activityhabits,smokingstatus,previous pre-term birthandpreviousmiscarriagewasobtainedatthefirst pre-natal visit either by reviewing the medicalrecords or by atelephoneinterview.Theinclusion/exclusioncriteriawas determinedatthisinitialvisitbytheattendingobstetrician.
Outcomes
Primaryoutcomes
Total maternal weightgain (kg) and excessivegestational weight gain (yes/no) were recorded. Total gestational weight gain wascalculated on the basis of the pregravid weight(firstprenatalconsult)andweightatthelastclinic visit before delivery (week 36---38). Excessive gestational weightgainwasdefinedaccordingtotherecommendations of the 2009 Institute of Medicine (IOM) guidelines40 cate-gorized by pre-pregnancyBMI for each woman:>18kgfor underweight; >16kgfor normal weight;>11.5kg for over-weight; and >9kg for obese women. Cases of gestational diabetesand1hOralGlucoseToleranceTest(OGTT) infor-mationwascollectedfromhospitalrecords(week24---26).
Secondaryoutcomes
Maternal gestationalage at delivery,typeof delivery and birthweightwerecollectedfromhospitalrecords.Newborns wereclassifiedashavingmacrosomiawhenbirthweightwas >4000×gandlowbirthweightwasdefinedas<2500×g.41 Primaryandsecondaryoutcomeswereassessedby health-careprofessionals.
Statisticalanalyses
Sample size was determined based on a priori widely accepted power calculation.42 Intotal, 340subjects were neededtoachieve80%powertodetectastatistically signif-icantdifferenceinmaternalweightgaintakingintoaccount previous dataonthisvariable.The samplesizewas inten-tionally increased to account for patient withdrawal and possibleproblemsforfollow-up.
AKolmogorov---Smirnovtestwasperformedtoverifythe normalityofthedatainthestudyvariablesandshowedthat itwasnon-parametric(p<0.05).Thus,Mann---Whitneytests were performed to analyze possible differences between thegroupsforcontinuousvariables(maternalweightgain, oral glucose tolerance test (OGTT), maternal age, gesta-tionalage,pre-pregnancyBMIandbirthweight).ThePearson 2 test was completed with the observation of standard-izedadjustedresiduals andwasusedtoassessdifferences betweencategoricalvariables(excessiveweightgain, ges-tationaldiabetes,parity,modeofdelivery).Statisticaltests useda2-sided0.05alphalevelandSPSS24.0wasusedto analyzethedata.Allanalysesweredoneonan intention-to-treatbasis.
Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on Table1 Maternalcharacteristics.
CG(n=222) EG(n=234)
Maternalage* (mean±SD)
31.04±3.78 31.75±4.68
Pre-pregnancyBMI (mean±SD)
23.66±3.81 23.50±3.79
Pre-pregnancyBMIcategories(n/%)
<18 6(2.7%) 5(2.1%)
18---24.9 157(70.7%) 160(68.4%)
25---29.9 45(20.3%) 54(23.1%)
>30 14(6.3%) 15(6.4%)
Parity(n/%)
Nopreviousbirth 162(73%) 142(60.7%) Onepreviousbirth 54(24.3%) 77(32.9%) Morethanone
previousbirth
6(2.7%) 15(6.4%)
Previousmiscarriage(n/%)
None 162(73%) 173(73.9%)
One 53(23.9%) 51(21.8%)
Twoormore 7(3.2%) 10(4.3%)
Studylevels(n/%)
Primaryschool 76(34.2%) 30(12.3%) Secondaryschool 97(43.7%) 87(37.4%) Tertiaryeducation 49(22.1%) 117(50.0%) Smoking(n/%) 49(22.1%) 44(18.8%)
* Years.
Results
(
Fig.
1
)
Baselinecharacteristics
BaselinecharacteristicsforbothgroupsarelistedinTable1 andweresimilarbetweengroupsformostofthevariables.
Mainoutcomes
Differencesinmainoutcomes(maternalweightgain,OGTT andcasesofGDM)arepresentedinTable2.Maternalweight gain was significantly lower in the EG compared to the CG (12.19 vs 13.33kg respectively, U=22044, p=0.005). In line with these results, standardized adjusted resid-uals in Pearson 2 suggested that the ratio of women that gained excessively was higher in the CG than the EG (30.2% vs 20.5% respectively; odds ratio, 0.597; 95% confidence interval, 0.389---0.916; p=0.018). A significant differencewasalsofoundfortheOGTTresults(EG=116.56 vs CG=121.63mg/dL, U=23,158, p=0.045). Finally, stan-dardizedadjustedresidualsinPearson2suggestedthatthe ratioofwomen diagnosedwithGDMwashigherintheCG thantheEG (6.8%vs2.6% respectively;oddsratio,0.363; 95%confidenceinterval,0.138---0.953;p=0.033).
Othermaternalandneonataloutcomes
Otheroutcomesofinterest analyzedinthe studyare pre-sentedinTable3.Amongmaternaloutcomes,nodifferences
werefoundforgestationalage,numberofpreterm deliver-iesor modeof delivery.In regardstonewborn outcomes, nodifferences werefound for birthweight between study groups.Ourresultsshowedthat,although the2test was notsignificant,theratioofneonatemacrosomiawasslightly higherintheCGthanintheEG(7.2%vs3.4%respectively; oddsratio,0.456;95%confidenceinterval,0.191---1.087).
Discussion
Theaimofthepresentstudywastoexaminewhether reg-ularandsupervisedphysicalexerciseduringpregnancycan influencepreventionofexcessivematernalweightgain,and GDM,whicharebothcloselyrelatedfactors.Similartoour previous work, the main strength of the current study is thecombinationoflightresistance,toning,aerobicdance, coordination, stretching and pelvic floor muscle training inthesameprogramthroughoutpregnancyandexamining theresultanteffectsonoutcomes.Themainfindingofthis studyisthattheexerciseprogramreducedthetotal(mean) maternalweightgainaswellasthecasesofexcessiveweight gainandGDM.
Ourresultsarerelevantfromaclinicalandhealthcare pointofviewduetotheincreasingprevalenceofthesetwo parametersinrecentyears,inparallelwiththealarmingrise ofworldwideoverweightandobesity.11,12Furthermorethe interpretationofourresultspromotetheuseofmoderate andsupervisedphysicalexercisethroughoutpregnancyasa methodtoincreasepreventionofpregnancycomplications and improve quality of life for pregnant women without adverseeffectsonmaternalandfetalwell-being.
Regardingtheexternalvalidityandgeneralizabilityofour findingsthehighadherence(≥80%attendance)ofthislarge RCTforallpre-pregnancyBMIcategoriesstronglysupports theextensionofthepresentresultstothehealthypregnant population.
In regards to the newborn health outcomes, although birthweightwassimilarinneonatesbetweentheCGandthe EG,thepercentageofnewbornswithmacrosomiawaslower intheEG.Wehadpreviouslyobserved37,38thiseffect,and thereforethisstudyprovidesadditionalevidencethat phys-icalexercisemayimproveperinataloutcomesbypreventing excessiveaccumulationofweightduringfetaldevelopment. Other authors have previously investigated the impact of prenatal exercise onexcessive gestational weightgain and GDM.43---55 Among the great variety of study designs used, RCTs are the most reliable as they allow manage-mentof independentvariables(exercise programdesign). CurrentliteratureavailableonRCTsincludesagreatvariety ofexerciseprogramsused.Itmightexplainthedifficultyin determiningtheexacttypeandfrequencyofexerciseduring pregnancythatisrequiredtopreventandtreatGDM.
From a methodological point of view the more adap-tive/desirable outcomes are reportedby those studies in whichasupervisedintervention(exerciseprogram) includ-ingalargevarietyofexercises(aerobic,resistance,pelvic floorandmusclestrengthening,stretching,etc.)havebeen providedthroughoutthepregnancy.46---51
Regardless of the variability among exercise interven-tions, most researchers agree that prenatal exercise is an excellent way for controlling maternal weight gain
Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on Table2 Maternalweightgain,oralglucosetolerancetestandgestationaldiabetes.
CG(n=222) EG(n=234) Pvalue Betweengroup differences
95%CI
Maternalweightgain*(mean±SD) 13.33±4.08 12.19±3.70 .005 1.14±0.37 0.42---1.86 Maternalexcessiveweightgain(n/%) 67(30.2%) 48(20.5%) .018
OGTT**(mean±SD) 121.63±29.56 116.56±29.69 .045 5.43±2.70 0.12---10.74
Gestationaldiabetes(n/%) 15(6.8%) 6(2.6%) .033
* Kilograms(kg).
OGTT:oralglucosetolerancetest. **Milligramsperdeciliter(mg/dL).
Table3 Othermaternalandnewbornoutcomes.
CG(n=222) EG(n=±234) Pvalue Betweengroup differences
95%CI
Mother
Gestationalage*(mean±SD) 277.18±9.75 277.21±12.81 .45 −0.04±1.07 −2.14to2.07 Pretermdelivery(>37weeks)(n/%) 7(3.2%) 10(4.3%) .53
Modeofdelivery(n/%)
Normal 138(62.2%) 156(66.7%) .41
Instrumental 38(17.1%) 30(12.8%)
Cesarean 46(20.7%) 48(20.5%)
Newborn
Birthweight**(mean±SD) 3256.34±465.94 3266.58±451.52 .60 −10.23±43.00 −94.74to74.28
Macrosomia(n/%) 16(7.2%) 8(3.4%) .07
* Days. **Grams(g).
duringpregnancy. Ourresults arein consensuswithmany authors,43---46 and with our previous studies on this health outcome.47,48
However, as we mentioned previously the relationship betweenexercise and GDMhas been unclear.While some evidencesuggestsahigh efficacyintheuseofexerciseas apreventive method,49---51 literaturehasbeen inconsistent ontheeffectofprenatalexercisewhenusedasatreatment methodforreducingriskfactorsforGDM.42---55Differencesin exerciseprogramsmayexplainthis.Inouropinionthe vari-anceinthedurationoftheprograms,lengthofthesessions, adherenceandespeciallythetypeofexercisesused, con-tributetothedifferencesobservedintheresultsofstudies.
Strengthsandlimitations
Themajorstrengthsofourstudyincludethelargenumber of participants in this RCT, the high adherence to inter-vention(>80% attendance) andthe identification of those women in the CG who did not remain sedentary. In our opinion,thepresentresultsprovidehealthcarepractitioners withevidence-basedinformationthatcanbeusedto recom-mendsupervisedphysicalexercisethroughoutpregnancyto maintainorimprovethequalityoflifeofpregnantwomen includinglaborandbirth.
One limitation of the current study wasthat nutrition or energyintake wasnot assessed, however, allpregnant womenhad(bytheirobstetriciansandmidwives)standard
care which included regular information about a healthy lifestyleduring pregnancyincludingnutritioninformation. Therefore the supervised exercise program was the only difference between study groups. In addition, we found differencesbetweenthestudygroupsforparityand educa-tionallevelofparticipantswhichcouldpotentiallyinfluence theresults.
Theimpracticalityofinstitutingthistypeofasupervised activityprogramforpregnantwomenonamassscalemaybe anotherpotentiallimitationofthepresentstudy. Further-more,our studyfocused ona Spanishpopulation andwas conducted intwo tertiarycare hospitals inMadrid, which maylowertheexternalvalidityofourfindings.
Conclusion
We conclude that a supervisedphysical exercise program initiated early and maintained throughout pregnancy can reducetheriskofexcessivematernalweightgainandGDM.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
Acknowledgements
Theauthorswouldliketoacknowledgethetechnical assis-tance of the Gynecology and Obstetrics Department of
Please cite this article in press as: Barakat R, et al. Exercise during pregnancy has a preventative effect on ‘‘Hospital Severo Ochoa’’ and the health practitioners of
Centro de Salud Los Pedroches, Centro de Salud Leganés Norte,Madrid,Spain.
Theauthorsalsowouldliketoacknowledgethetechnical assistance for the English revision to Taniya Singh Nagpal fromUniversityofWesternOntario(Canada).
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