The efeec o m ceerma ee eeecie r m ceerma mrn o ecma hemach cr oeie ee ermrc er 223 Pregledni znansTveni članek de mec erc o hyic cheem y, F meuacy o hemach iecere ei, Urcveeiccy o ljuoa jmrm, ljuoajmrm, sa vercm Korespondenca/ Correspondence: ivmrm He vmccr, e: cv mrm. hevmccr@e mca.e Ključne besede: ceaeirm nejmvr ic ; neoea ic; r iečrce e; znemvje; r v e jerček Key words: eeeeecie; oeiccy; e eermrc er; he mach; cromrc Peci ea : 9. 4. 2019 s eejec : 12. 8. 2019 @publisher.id: 2944 @primary-language: sl, er @discipline-en: Mcee oc a e y mrn c ur a e y, sc mc a e y, neue oc a e y, Ore a e y, Human reproduction, Cmenc v mieuame iyic e , Mecmo ace mrn h e rma nci eneei, Puoace he mach ( eeu mcc rma encecre), P iyehcmcey @discipline-sl: Mcke oc a ecjm cr c ur a ecjm, sc mc a ecjm, neve oc a ecjm, Ork a ecjm, Reprodukcija človeka, see e cr žca je, Mecmo are cr h e rike crje, Jmvr z nemvicv (v meicv ec neau), P ichcmcecjm @article-type-en: encc ecma, Oececrma iecerccoce mecceae, Review article, sh ec iecerccoce mecceae, Pe o eiic rma mecceae @article-type-sl: Uv nrck, izvcerc zrmricverc čamrek, Pregledni znanstveni članek, kacrcčrc ec ee , sce k vrc čamrek @running-header: The ef eec o mc eerma ee eeecie r mc eerma mrn o e cma he mach cr oeie e eermrc er @reference-sl: znemv v eicr | me ee – m eca 2020 | l ecrck 89 @reference-en: znemv v eicr | Mmeeh – a eca 2020 | v au e 89 The effect of maternal exercise on maternal and foetal health in obese pregnant women Učinek telesne dejavnosti pri nosečnicah z debelostjo na zdravje nosečnice in novorojenčka Darija Šćepanović, Ivana Hrvatin Abstract Background: Obesity during pregnancy represents a global problem and is a major risk fac- tor for complications during pregnancy and labour. Emerging evidence suggests that physical activity during pregnancy might be beneficial for both maternal and foetal health without side effects. The purpose of this systematic review was to review trials evaluating the effect of physi- cal activity on maternal and foetal health in obese pregnant women. Methods: PRISMA guidelines were followed. We searched for randomized controlled trials pu- blished until June 2018 on the PubMed, PEDro and CENTRAL databases. We included articles that had a well described physical activity intervention and studied obese pregnant women with BMI > 30 kg/m 2 . Results: Ten articles were included in the review. All articles included a physical activity inter- vention, seven articles included also a dietary intervention. Four articles included a pedometer- -based intervention, six articles opted for a supervised physical activity intervention. Physical activity with or without dietary intervention had no effect on lowering the risk for gestational diabetes mellitus or improving neonatal or other maternal outcomes. There were mixed results in gestational weight gain and mode of delivery. Conclusion: We can conclude that physical activity during pregnancy has mixed results on maternal and foetal health in obese pregnant women. There is no evidence from randomized controlled trials that PA during pregnancy in obese women improves maternal or neonatal ou- tcomes, and therefore no clear statements on beneficial effects of PA in this population can cur- rently be made. Izvleček Izhodišče: Debelost med nosečnostjo je svetovni problem in velik dejavnik tveganja za nastanek zapletov med nosečnotjo in porodom. Nova dognanja trdijo, da je telesna dejavnost med noseč- nostjo koristna za mater in novorojenčka. Namen sistematičnega pregleda literature je seznani- tev z randomiziranimi kontroliranimi raziskavami o učinkih telesne dejavnosti na zdravje matere in ploda pri nosečnicah z debelostjo. Metode: Iskali smo randomizirane kontrolirane raziskave, objavljene do junija 2018, na spletnih podatkovnih bazah PubMed, CINAHL, PEDro, CENTRAL ali Medline. Vključili smo raziskave, ki so imele natančno opisan ukrep za telesno dejavnost in so vključile nosečnice z debelostjo, ki so imele indeks telesne mase (ITM) > 30 kg/m 2 . Rezultati: V pregled je bilo vključenih 6 raziskav, ki so telesno dejavnost kombinirale s svetova- njem o zdravi prehrani. Telesna dejavnost s prehranskim svetovanjem ali brez njega ni učinkovi- ta pri zmanjšanju tveganja za nastanek sladkorne bolezni med nosečnostjo ali izboljšanje zdrav- ja novorojenčka. Učinek telesne dejavnosti na gestacijsko telesno težo pa ni jasen. Samo ena 224 znemv v eicr | me ee – m eca 2020 | l ecrck 89 rePrOdUkCiJa čl Oveka vključena raziskava je vključila nadzorovano telesno dejavnost, medtem ko so ostale vključevale zgolj svetovanje in spodbujanje k povečanju količine hoje dnevno s pedometrom. Zaključek: Zaključimo lahko, da učinki telesne dejavnosti pri nosečnicah z debelostjo niso jasni. Na podlagi randomiziranih kontroliranih poskusov ne moremo trditi, da telesna dejavnost no- sečnic z debelostjo izboljša zdravje matere ali otroka. Citirajte kot/Cite as: dmecjm Šće mr vcć, iv mrm He vmccr. The ef eec o mc eerma ee eeecie r mc eerma mrn o ecma he mach cr oeie e eermrc er. znemv v eicr. 2020;89(3–4):223–34. DOI: 10.6016/znemvveicr.2944 1 Introduction Obesity in pregnancy is usually defi- ned as a body mass index (BMI) of 30 kg/ m 2 or more at the first antenatal consul- tation (1). It represents a global problem and is a major risk factor for complicati- ons during pregnancy and labour (2,3). Approximately half of women in their reproductive stage are either overwe- ight (BMI 25 to 30), or are obese (BMI 30 or above) (4,5). Obesity during preg - nancy is associated with higher risk of pre-term delivery (6), birth-asphyxia-re- lated complications (7), pre-eclampsia, gestational diabetes mellitus (GDM), prolonged second stage of labour, de- livery by caesarean section, wound in- fection, postpartum haemorrhage, early neonatal death or neonatal admission to intensive care (8-11) and infant mor - tality (12). Because of these associations maternal obesity has become one of the most challenging health care problems in the 21 st century obstetrics (2,13). Emerging evidence suggests that physical activity (PA) during pregnancy might be beneficial for both maternal and foetal health without side effects (14,15). Findings in the literature also suggest that increasing PA levels during preg- nancy is effective in the prevention of GDM, hypertension, dyspnoea, excessi- ve gestational weight gain (GWG), and high birth weight, among others (16-23). In a population based cohort study that included 98,820 women who delivered in Slovenia, the authors concluded that excessive GWG is a significant risk factor for pre-eclampsia, while low GWG is an important protective factor against PE in obese women (24). Maternal exercise may have benefits for the new born, such as higher neurodevelopment (25,26), better heart function, improved he- art rate variability (27) and lower body fat (25). Exercise may improve the preg- nant women’s quality of life and reduce stress (15,28-30), which might protect the foetus (31). A recent meta-analysis that included obese and overweight pregnant women concluded that exerci- se interventions reduced GWG and the risk for GDM. No evidence was found with respect to benefits of exercise du- ring pregnancy for infants (32). Another recent systematic review found that 30 to 60 minutes of aerobic exercise per- formed three to seven times per week during pregnancy is associated with a reduction in the incidence of preterm birth in overweight and obese pregnant women (33). However, no literature re - view was performed in obese pregnant women only. Obese pregnant women should be encouraged to engage in healthy lifestyle modification in pregnancy, which inclu- des physical activities and judicious di- ets. Obese women should start with low- The efeec o m ceerma ee eeecie r m ceerma mrn o ecma hemach cr oeie ee ermrc er 225 Pregledni znansTveni članek -intensity, short periods of exercise and gradually increase as able (34). Literature suggests that obese pregnant women should engage in PA for 3 to 5 times per week or on most days of the week. Each PA session should last between 20 to 30 minutes (35,36). The Slovenian recommendations on PA during preg- nancy state that pregnant women should exercise every day of the week for at least 30 minutes at moderate intensity (37). All-though most guidelines for exercise intensity can be used in women who are pregnant and obese, the results from se- veral randomized controlled trials sug- gested that light to moderate intensity activity may be best for women who are pregnant and obese. The perceived exer- tion should be evaluated during P A using the Borg scale. A personalized exercise programme including personal goals should be formed (36) . In women who are pregnant and overweight or obese, a variety of exercise programmes have been implemented and proven to be safe and effective. These programmes inclu- de resistance training (23,38), stationary cycling (39,40), aerobics classes (41) and walking (42,43). There are many new published trials evaluating the effects of PA on maternal health in obese pregnant women, but so far no systematic review has focused only on obese pregnant women. Previous re- views focused on overweight and obese women together (32,33,36,39,44,45,46). Overweight women with a BMI below 30 may also benefit from the particular recommendation, however, the chosen BMI cut-offs reflect careful conside- ration given to the balance of medical intervention versus risk, differences in local prevalence of maternal obesity, and resource implications for local he- althcare organisations (1). The purpose of this systematic review was to review trials evaluating the effect of PA in obese pregnant women and, based on the re- sults, evaluate the optimal exercise pro- gramme to diminish the risks associated with obesity and pregnancy. 2 Methods The PRISMA guidelines were fol- lowed. Literature search was conducted on the following databases: PubMed, CENTRAL and PEDro. The search was conducted until the end of June 2018. A combination of the following search terms was used: ‘obese’ OR ‘obesity’ AND ‘pregnant’ OR ‘pregnancy’ AND ‘physical activity’ OR ‘exercise’ AND ‘health’ . Filters were applied to include only English language and human studies. The trials included needed to be randomized con- trolled trials that evaluated the effect of PA on maternal health or maternal and foetal health in obese pregnant women. They could be either combined with a dietary intervention or not. The inclu- ded articles needed to have a specific and described exercise programme and should include only pregnant women with BMI score 30.0 kg/m 2 or above. All included women needed to be without exercise contraindications. Only arti- cles written in English were included. We excluded articles that examined the effect of PA on postpartum depression or mental health only and articles that measured the effect of PA on urinary in- continence. All articles were reviewed by one re- searcher. After removing duplications, articles were reviewed by titles and ab- stracts by the same researcher and dis- cussed with the senior author. Articles that met the inclusion criteria in abstract and title review were assessed for eligibi- lity in full text. Primary outcomes were maternal and neonatal outcomes. For maternal outcomes we included relative risk for 226 znemv v eicr | me ee – m eca 2020 | l ecrck 89 rePrOdUkCiJa čl Oveka GDM and GWG. For neonatal outcomes we decided to include birth weight, ge- stational age at delivery and large for gestational age, as they most frequently appear in the literature. Secondary ou- tcomes included fasting insulin levels, pre-eclampsia, systolic and diastolic ma- ternal blood pressure, delivery by caesa- rean section and fasting HDL and LDL levels. Outcomes and characteristics were extracted from each of the included studies. 3 Results Our search yielded 151 publications eligible for screening. After title and abstract screening, 34 articles were in- cluded for full text review. Ten of these met our inclusion criteria. The search and screening process are presented in Figure 1. Table 1 presents the methodological approaches used in the included studies. Six articles (42,43,49,50,52,54) included a dietary intervention or some informati- on on healthy eating that aimed at a he- alth gestational weight gain of less than 5 kg that is linked with fewer complica- tions during pregnancy and delivery. All obese pregnant women allocated to the control groups received standard prena- tal care. The diagnosis of GDM was based on a 75 g, 2-hour oral glucose toleran- ce test that was conducted between 24 and 28 weeks of gestation, with the dia- gnosis being based on the International Association of Diabetes in Pregnancy Studies Group criteria. Gestational we- ight gain was calculated as the weight measured at a visit during gestational weeks 36 to 37 minus the self-reported or measured pre-pregnancy weight. Exercise has no effect on GDM in all of the included articles as shown in Table 2 . There were mixed results re- garding the effect of exercise on GWG. Five articles reported a significant re- sult (42,43,49,51,54) and three articles re - ported an insignificant result (47,52,53). Renault and colleagues (54) found that gestational weight gain was significantly lower in the PA and dietary intervention as well as in the PA only group compa- red to the control group (p = 0.008), but Records after duplicates removed (n = 743) Records identified through database searching (n = 995) Additional records identified through other sources (n = 8) Records screened (n = 151) Records excluded (n = 592) Full-text articles assessed or eligibility (n = 34) Full-text articles excluded, with reasons (n = 24) Not randomized trials (n = 3) Full text not found ( n = 2) Ineligible populations (n = 13) Ineligible interventions (n = 6) Studies included in qualitative synthesis (n = 10) Figure 1: PRISMA diagram. The efeec o m ceerma ee eeecie r m ceerma mrn o ecma hemach cr oeie ee ermrc er 227 Pregledni znansTveni članek Table 1: Methodological approaches used in the studies. Authors N Intervention period Intervention PA Outcomes measured Ong et al., 2009 (47) 12 18–28 wk of gestation PA, C Home based supervised exercise performed on an upright stationary cycle ergometer, 3x per week, 25 to 45 min GDM, GWG, maternal aerobic fitness, self reported physical activity Callaway et al., 2010 (48) 50 12 wk of gestation to delivery PA, C Individualized exercise plan, regular exercise advice, paper based diaries GDM, fasting insulin, fasting glucose, MET h/week, >900 kcal/week Vinter et al., 2011 (49) 304 10 to 14wk of gestation to 36 wk of gestation PA and DI, C encouragement to be active for 30 to 60 min daily, pedometer, free full-time membership to a fitness centre for 6 months with closed training with PT for 1 h per week, group sessions for 4 to 6 times during pregnancy GWG, systolic and diastolic blood pressure, VO 2 max, GDM, caesarean section, pre- eclampsia, neonatal outcomes Poston et al., 2013 (50) 183 15 to 17 wk of gestation to delivery PA and DI, C individual session with health trainer followed by 8 group sessions, advice on increasing step count monitored by pedometer, DVD of specifically devised pregnancy exercise regime GDM, neonatal outcomes, GWG, mode of delivery, pre-eclampsia, blood loss at delivery, inpatient nights, blood pressure, neonatal outcomes Renault el al., 2014 (43) 283 11 to 16 wk of gestation to delivery PA and DI, PA, C A daily step count of 11000, assessed by pedometers GWG, systolic blood pressure, diastolic blood pressure, hypertension, pre-eclampsia, induction of labour, caesarean section, neonatal outcomes, gestational hypertension Bisson et al., 2015 (51) 50 11 to 36 wk of gestation PA, C 1 hour long sessions, stationary cycling (5 to 10 min), treadmill walk (15 to 30 min), muscle exercise (20 min), cool down period, three times per week GWG, caesarean delivery, GDM, gestational hypertension, neonatal outcomes Dekker Nitert et al., 2015 (52) 50 12 to 36 wk of gestation PA and DI, C individualized exercise plan meeting specific energy expenditure based on personal preferences and ability, monthly advice by physiotherapist, paper based diaries and self-monitoring GWG, weight, BMI, systolic and diastolic blood pressure, fasting glucose, fasting insulin, fasting cholesterol, fasting HDL, fasting LDL, neonatal outcomes Poston et al., 2015 (42) 1555 15 wk of gestation to delivery PA and DI, C individual interview, 8 individual or group sessions of 1 h for 8 weeks, DVD of exercise regimen, incremental increase of walking from a pedometer assessed baseline GDM, GWG, maternal anthropometric measurements, fasting plasma insulin, insulin resistance, fasting trygcerides, LDL and HDL cholesterol, pre- eclampsia, systolic and diastolic blood pressure, mode of delivery, induction of labour, blood loss at delivery, inpatient nights, neonatal outcomes 228 znemv v eicr | me ee – m eca 2020 | l ecrck 89 rePrOdUkCiJa čl Oveka there were no significant differences fou- nd between the two intervention groups (p = 0.57). Four articles, including 2044 women, measured the effect of PA on fasting insulin levels (42,45,52,54). No diffe - rences were seen among all four stu- dies with p-values raging from 0.05 to 0.57. The highest difference was 5.7 mmol/L (47) between the control and intervention group, while other authors reported differences of between -0.1 mmol/L (52), 1.6 mmol/L (54) and 0.7 mmol/L (42). Three articles inclu - ding 1994 women (42,52,54) assessed the effect of maternal PA on HDL and LDL levels. Again, no difference was reported among the groups. P-values ranged from 0.50 to 0.93 for HDL cholesterol and from 0.27 to 0.32 for LDL cholesterol le- vels. Two articles reported no difference in levels of HDL and LDL measured in mmol/L between the intervention and control group (42,54), while one article reported a difference of 0.2 mmol/L in HDL and 0.9 mmol/L in LDL measure- ments between the control and interven- tion group (52).Three articles including 687 women (43,49,52) reported the effect of PA on systolic with a difference of 1–2 mmol/L between the control and in- tervention group (43,49,52) and diastolic with a difference of 1 mmol/L (43,49,52) maternal blood pressure. There was no significant result reported. PA had no effect on the occurrence of pre- -eclampsia as reported by two articles including 2142 women (42,43). Poston and colleagues (42) reported the occur - rence of pre-eclampsia in 4 % of par- ticipants in both the intervention and control group. Renault and colleagu- es (43) reported that 1.5 % of women in the control and 2.2 % of women in the intervention group were diagnosed with pre-eclampsia. Five articles including 2463 women (44,49,51,53) reported that PA had no effect on elective or emer- gency caesarean section, with p-values raging from 0.16 to 0.79. The rate of ca- esarean section was between 20 % (53) and 37 % (43) in the control group and between 18 % (53) and 35 % (42) in the intervention group. Renault and collea- gues (43) found an insignificant rate of deliveries by caesarean section (p = 0.16), but a significantly lower rate of emer- gency/unplanned caesarean section in the dietary and lifestyle counselling gro- up (p = 0.015). There were also no significant diffe - rences in neonatal outcomes in all of the included articles. Results are shown in Table 3. Authors N Intervention period Intervention PA Outcomes measured Daly et al., 2017 (53) 88 13 wk of gestation to 6 wk postpartum PA, C 3 PT supervised exercise classes per week during pregnancy and 6 weeks postpartum, 50–60 minutes GDM, GWG, induction of labour, mode of delivery, length of labour, neonatal outcomes, postpartum weight retention Renault et al., 2017 (54) 389 11 to 14 PA and DI, PA, C encouragement to increase to 11000 steps per day, monitored by pedometer GWG, fasting HDL, fasting LDL, cholesterol, fasting triglycerides, fasting insulin, C-peptide, leptin, GDM leeern: n – ru oee o meccec mrci; P a – hyicema meccvccy; di – ncecmey crceevercc r; C – e rce a; sC – icmrnmen eermcma emee; gWg – eeicmcc rma ecehc emcr; gdM – eeicmcc rma ncmoecei eaaccui; PT – hyic cheem cic ; Hdl – hceh nericcy ac e c ecr; ldl – a nericcy ac e c ecr. The efeec o m ceerma ee eeecie r m ceerma mrn o ecma hemach cr oeie ee ermrc er 229 Pregledni znansTveni članek Three articles (42,43,53) including 1926 women, examined the occurrence of pre-term birth. All articles reported an insignificant result with p-values gre- ater than 0.05. In the control group pre- -term birth occurred in 2 % (42,43,53), while in the intervention group it occur- red in between 2 % (40) to 4 % (43,53). Four articles (43,43,51,53) including 1976 women, measured the outcome of small for gestational age.The p-values in all studies were greater than 0.05. In the control group there were between 5 % (43) to 16 % (53) and in the interven - tion group between 0 % (51) to 13 % (42) of infants small for gestational age. 4 Discussion To our knowledge this is the first systematic review of articles that stu- died the effect of physical activity on maternal and neonatal health in obese pregnant women. The results from our systematic review show that no exercise or increasing habitual PA intervention is effective in improving neonatal ou- tcomes and preventing GDM in obese pregnant women. Our results are consis- tent with recent systematic reviews that focused on obese and overweight women (32,33,36,39,44,45,46). Major di - fferences can be seen in the methodolo- gical approaches used in the studies. Table 2: Results of the included studies on GDM, GWG. Authors GDM GWG Intervention Control Intervention Control Ong et al., 2009 (47) / / 3.7 (3.4) p:0.155 5.2 (1.3) Callaway et al., 2010 (48) 3 (16 %) p:0.57 5 (23 %) / / Vinter et al., 2011 (49) 9 (6 %) p:0.76 8 (5.2 %) 7.0 p:0.014* 8.6 Poston et al., 2013 (50) 22 p:0.574 24 / / Renault et al., 2014 (43) 6 (5.8 %) 7 (5.2 %) 8.6 p:0.024* 10.9 Bisson et al., 2015 (51) 3 p:0.60 5 12.3 (5.9) p:0.03* 12.2 (5.9) Dekker Nitert et al., 2015 (52) / / 7.87 (4.00) p:0,81 8.28 (6.10) Poston et al., 2015 (42) 160 (25 %) p:0.68 172 (26 %) 7.19 (4.6) p:0.041* 7.76 (4.6) Daly et al., 2017 (53) 25 (58.1 %) p:0.51 21 (48.8 %) 6.2 (6.0) p:0.15 7.89 (4.8) Renault et al., 2017 (54) / / 8.7 p:0.02* 10.7 dmcm mee emr (sd) e ru oee o er (%); leeern: gdM – eeicmcc rma ncmoecei eaaccui (ru oee o eeermrc er ncmer ien); gWg – eeicmcc rma ecehc emcr(ke); *- icmcciccemaay icercocemrc eeiuac. 230 znemv v eicr | me ee – m eca 2020 | l ecrck 89 rePrOdUkCiJa čl Oveka There were differences in dosage of exercise duration and timing. All inclu- ded articles started the PA intervention in the second trimester or towards the end of the first trimester. Women are en- couraged to start PA as soon as possible in pregnancy or continue with PA from before pregnancy (55,55). Seven articles included a supervised PA intervention that differed in frequency and durati- on (42,47,48,49,51-53). In three articles the P A intervention was delivered 3 times per week (44,51,53), one article included supervised PA 4 to 6 times per week (49) and one article only once a week (42). Two articles included an individualised plan (48,52). In four articles the durati- on of each session was 1 hour (42,51,53), whereas in one article the duration was between 25 to 45 minutes (47). Literature suggests that obese pregnant women should engage in PA for 3 to 5 times per week or on most days of the week. Each PA session should last between 20 to 30 minutes (35,36,37). Five articles opted for a pedometer approach (42,43,49,50,54). The pedome - ter intervention has many limitations. Pedometers measure only ambulatory activity, cannot provide an accurate esti- mate of PA energy expenditure and have limited accuracy when measuring physi- cal activity at slower or faster speeds (57). Another limitation of a pedometer ba- sed intervention is the lack of measuring activity in water. As swimming is a po- pular PA among pregnant women, this can be considered as a major limitation of the studies. Another major concern is that there is no medical supervision. As a new form of PA can be hard to in- corporate in the daily routine without medical advice and a specific, perso- nalised programme, we consider this a major limitation of the study. On the other hand, there are also some positive characteristics of a pedometer approach. Table 3: Results of the included studies on neonatal outcomes. Authors Birth weight (g) GA LGA Intervention Control Intervention Control Intervention Control Vinter et al., 2011 (49) 3742 p:0.039 3593 40 p:0.952 40 23 (15.4 %) p:0.340 18 (11.7 %) Poston et al., 2013 (50) / / / / 7 (8 %) p:0.982 7 (8 %) Renault et al., 2014 (43) 3605 p:0.08* 3641 278 (11) p:>0.05 278 (12) 9 (6.9 %) p:>0.05 9 (6.7 %) Bisson et al., 2015 (51) 3575 (425) p:0.30 3455 (368) 39 (1) p:>0.05 39 (1) 4 (17 %) p:>0.05 3 (13 %) Dekker Nitert et al., 2015 (52) 3548 (459) p:0.12 3597 (304) 39 p:>0.05 39 / / Poston et al., 2015 (42) 3420 (580) p:0.37 3450 (580) 39.5 (2.0) p:0.89 39.5 (2.4) 71 (9 %) p:0.40 61 (8 %) Daly et al., 2017 (53) 3532 (477.1) p:0.99 3534 (552.3) 39.6 (1,8) p:0.32 39,2 (1.6) 3 (6.8 %) p:0.51 2 (4.6 %) dmcm mee emr (sd) e ru oee o cromrci (%); leeern: ga – eeicmcc rma mee ( eeki); lga – ameee o e eeicmcc rma mee (ru oee o cromrci); *- icercocemrc eeiuac. The efeec o m ceerma ee eeecie r m ceerma mrn o ecma hemach cr oeie ee ermrc er 231 Pregledni znansTveni članek This intervention is inexpensive and can easily be implemented into daily clinical practice. Pedometers are user-friendly and commonly known. They are usually small and worn on the waist or wrist. Our results show that no interventi- on was successful in preventing GDM. Reasons for this limitation can be expla- ined by the fact that all of the included studies started with the intervention in the second trimester. Starting exercise in the second trimester can be practical for the researches and easier as the first tri- mester pregnancy symptoms, including nausea, vomiting and extreme fatigue, stop (55,56). Since many women alre - ady start gaining weight in the first tri- mester (58), exercise interventions likely need to begin very early in the pregnancy or perhaps already in the pre-pregnancy period to achieve maximal effects. With an early intervention we could achieve more, since with the progression of the pregnancy exercise becomes harder to accomplish. Another possible explanation for non-significant differences between in- tervention and control groups is that the PA was not of appropriate intensi- ty. The incremental rise in PA intensity achieved with the type of interventions, used in the included studies, is inadequ- ate for improving glucose tolerance. A minimum of 16 MET/h per week of PA is suggested to be needed to reduce the risk of GDM (59). This is equivalent to 40 min/day of walking. No article in- cluded in our review met the minimum amount of exercise needed to reduce the risk of GDM. It is possible that women allocated to the control group also incre- ased their level of PA, which further re- duces the power of the studies to detect differences. The results show that exercise inter- ventions have a mixed effect on GWG. Five articles concluded that a PA in- tervention is effective. Other recent studies, conducted in normal weight pregnant women, also report mixed effects (58,59,61). More studies are nee - ded to establish the conclusive effect of PA on GWG. In a systematic review of the effects of PA and PA plus diet inter- ventions on body weight in overweight or obese pregnant women the autho- rs concluded that supervised PA pro- grammes or personalised prescription are needed to prevent excessive weight gain for overweight and obese pregnant women (35). To increase knowledge about the effects of PA in pregnancy on delivery, neonatal outcomes and maternal he- alth in obese pregnant women longitu- dinal prospective studies with detailed descriptions of different types of die- tary interventions and PA are needed. Different types of PA should be inve- stigated to establish the least and most effective type of PA. For future studies, we recommend an early intervention with a personalized intervention pro- gramme. A major limitation of the studi- es included was the lack of guidance and control over PA. Since obesity requires a medical intervention, we recommend that physiotherapists or appropriately trained health trainers guide and provi- de advice to pregnant women. 5 Conclusion This systematic review has shown that PA is not an effective intervention for lowering the risk of GDM or im- proving neonatal outcomes. There were also mixed results regarding the effect of PA on gestation weight gain and delive- ry mode. There are many limitations of the included studies that could explain the inconclusive results. Further high quality and large studies are needed to determine the effectiveness of a PA in- 232 znemv v eicr | me ee – m eca 2020 | l ecrck 89 rePrOdUkCiJa čl Oveka tervention with and without a dietary intervention. Future studies should in- vestigate the difference between various PA interventions that should be perso- nalized and started as soon as possible, ideally before the pregnancy. There is no evidence from randomized controlled trials that PA during pregnancy in obese women improves maternal or neonatal outcomes, no clear statements on bene- ficial effects of PA in this population can currently be made. 6 Declaration Conflicts of interest: The authors declare that no conflicts of interest exist. Funding: The study was not founded. Ethical approval: There was no ethi- cal approval needed since this is a syste- matic review. References 1. M nnee J, Fcczic ri kJ. CMaCe/rCOg J crc gucneacre. Mmrme e erc o W er cch Ooeiccy cr Pe eermr- ey. l rn r: r y ma C aae ee o Ooic ecececmri mrn gyrmee a ecici; 2013. 2. neai r sM, Mmcche i P, P ic r l. Mmc eerma ecmo aci mrn oeiccy: ncocmoae necee crmrci o eeermr- ey uce e. Hu r e e n U nmc e. 2010;16(3):255-75. 3. Oveier P, rmi uiier s, kei nea U. efeec o ee eeermrey mceerma vee ecehc mrn oeiccy r eeermr- ey uce e. Ooic ec gyree a. 2011;118(2 Pc 1):305-12. 4. Faeema kM, Cmee aa Md, Oener Cl, Cueccr lr. Pe evmaeree mrn ceerni cr oeiccy m re U s mnuaci, 1999-2008. JaMa. 2010;303(3):235-41. 5. Mekemccre a, Mmeucee PJ, dmay n, F meeer M, MeMmh r l, Tueree MJ. T eerni cr mceerma oeiccy cr m ameee urcveeiccy h i ccma 2009-2013. aecm Ooic ec gyree a semrn. 2015;94(9):969-75. 6. Crmcccrecui s, vcaam e e, J hmrii r s, enicenc B rm y ak, Peeii r M, Wckice ö ak, ec ma. Mmc eerma oeic- cy mrn ecik o e ecee neacvee y. JaMa. 2013;309(22):2362-70. 7. Peeii r M, J hmrii r s, vcaam e e, Crmcccrecui s. Mmc eerma vee ecehc mrn oeiccy mrn eciki o ieveee ocech-mi hyecm-eeamcen e acemcc ri cr cee cromrci: m uamcc r-omien e h ec icuny cr s ener. Pl s Men. 2014;11(5):e1001648. 8. lee kk, rmjm ea, lee aJ, Bhmccmehmeym s, Bhmccmehme ym s, n e mr Je, e c ma. Mmc eerma Ooeiccy duecre Pe ee- rmrey aii ecmcei Wcch Pe e mcuee M ecmaccy mrn Mmj e Cmenc v mieuame everci cr lmcee lcoe. Hy eec eric r. 2015;66(5):938-44. 9. Pmeee s, smuee C, Mmzz m C s, gmeecm s, T zce rg, l ez aP, ec ma. i mec o mceerma ruceccc rma icmcui oe - o ee mrn nuecre eeermrey r re rmcma o ny e iccc r: a ee ii-ieecc rma icuny. dcmoecei Mecmo syrne. 2016;10(1):s7-12. 10. Cmecy d, akehueic C, smvmee r, suremcuaacrm l, r ocri r s, MeBecne M, e c ma. dcfeeerccma eere ee e eiic r cr oeie e eermrey. Pe eermrey Hy eec eri. 2014;4(3):232-3. 11. a mr s, Bcoc s, Mmkhn a, Fme q s, s T, Qmzc ra. anveeie oec mceerma uce e m re eeermrc vee ecehc er. P mk J Men sec. 2015;31(2):383-7. 12. J hmrii r s, vcaam e e, aac mr M, B rm y ak, gemrmch F, Crmcccrecui s. Mmc eerma vee ecehc mrn oe- iccy cr e meay eeermrey mrn ecik o cromrc ecmaccy: m uamcc r omien e h ec icuny cr s ener. BMJ. 2014;349:e6572. 13. T ea rc Mr, Be ceár aP, H ecm Bl, nmkm uem MU, acmaamh an, M e r aF, ec ma. Pe e eeermrey BMi mrn che ecik o eeicmcc rma ncmoecei: m iyice mcce eevce o che acceemcuee cch ecm-mrmayici. Ooei rev. 2009;10(2):194- 203. 14. Pece v Fceeca k, gamrcz a, Fmeevck Oaier M. The efceme y o neemce-c -vce e ui eeicicmree eeeeecie nuecre eeermrey: m emrn czen e rce aaen cecma. aecm Ooic ec gyree a semrn. 2015;94(1):35-42. 15. O’C rr e PJ, P unevcere Ms, Ce eii Me, M ca rW, Cam JF. smoecy mrn efceme y o iu eevcien iceerech cem- crcre mn c en cr e eermrey. J Phyi aec He mach. 2011;8(3):309-20. 16. Berjm cr dr, v mr ne W mcee aT, Pececi Cl. efeeci o ee eeecie r ncmicmici o che eeecui mon crci uieae cr che mrc ermcma mrn icrmcma eec ni: m iyic e mcce e evce . Phyic cheem y. 2014;100(1):1-8. 17. Hmaa dC, kmuo mrr da. efeeci o mee oce mrn iceerech e rnccc rcre r eeermrey uce ei. a J Ooicec gyree a. 1987;157(5):1199-203. 18. vmr P ea Mn, ruehmc sM, M cc am MF. Phyicema meccvccy mrn eeicmcc rma ncmoecei eaaccui. Men s ec sec. 2014;60:104-12. 19. Meazee k, sehucz Y, B uav mcr M, kmyiee B. Phyicema meccvccy mrn eeermrey: emenc vmieuame mnm cmcc ri, eee ernmcc ri mrn e eermrey uce ei. s eci Men. 2010;40(6):493-507. 20. de iey JC, Bucaee Cl, Wcaacm i Ma. n reen o e m eeermrc muie: hyicema meccvccy my eenuee che eeue- eeree o e eicmcc rma ncmoe cei eaaccui mrn e eeeam icm. eeeee s ec sec r ev. 2005;33(3):141-9. The efeec o m ceerma ee eeecie r m ceerma mrn o ecma hemach cr oeie ee ermrc er 233 Pregledni znansTveni članek 21. rucoe k ae, aachuczer e, O icnm n, v mr Meeheaer W, M a BW, ne ge c CJ, e c ma. The eeamcc rihc o ojeecc- veay emiueen hyicema meccvccy mrn ienercmey oehmvc ue cch eeicmcc rma ecehc emcr mrn ocech ecehc. J Peeermrey. 2014;2014:567379. 22. rucz Jr, Peemaei M, Peamez M, l ez C, luecm a, Bmemkmc r. su eevcien ee eeecie-omien crceevercc r c eeverc eeeeiicve eeicmcc rma ecehc emcr: m emrn czen e rce aaen cecma. Mmy Cacr Pe e. 2013;88(12):1388-97. 23. Bemrkic r gn, Mcceheaa BF, rymr ea, Okur nB. reicicmree ee eeecie neeeemiei che reen o e criuacr cr vee e- cehc er cch e eicmcc rma ncmoe cei eaaccui. a J Ooic ec gyree a. 2004;190(1):188-93. 24. Pee eu-seier T, k ece z, v nuiek vF, geešmk k, veenerck i. T cma eeicmcc rma ecehc emcr mrn che ecik o eeeeam icm oy ee- eeermrey o ny mii crnee emcee ecei: m uamcc r-omien e h ec icuny oe 2013 c 2017. J Peecrmc Men. 2019;47(6):585-91. 25. Cam JF. M e h e cece mrn reue nevea ercma uce e mc mee ocve ye mei o che fi ecre o er h e rccruen c ee eeecie e eeuameay che ueh uc e eermrey. J Pencmce . 1996;129(6):856-63. 26. Pmek JW, kc MH, e sJ, lee eH, kmre Js, Chmre Hk, e c ma. Mmc eerma ee eeecie nuecre eeermrey mfeeci cc - eh rnecma erzy mcce meccvccy mrn oc e ereici cr fi ecre oemcr. irc J neue iec. 2013;123(4):253-64. 27. Mmy le, seh acz sa, su crikc r, guicmoi r kM. aee oce eeeeecie nuecre eeermrey croauereei cromrc he mec emce v mecmocaccy mc re rch o me e. emeay Hu dev. 2014;90(1):33-8. 28. k au P, rmccmrer J, lu c r. Phyicema meccvccy mrn he mach-eeamcen qumaccy o acoe nuecre eeermrey: m iee rnm- ey mrmayici o m eauic ee-emrn cien cecma. Mmc eer Chcan He mach J. 2014;18(9):2098-105. 29. gmic r a, Pem mveiici H. Tce en, ny mrn eeermrc? eeeeecie my oe che mri ee. P iyeh a He mach. 2013;28(12):1353-69. 30. shcvmku me g, Bemrn r ar, sreaa Pg, smrccme -Muñ z P, J hri r nl, T ecvenc MH, e c ma. arcermcma ne eeiic- r: m emcc rmae o e icunycre ee eeecie. de e eii arececy. 2011;28(3):234-42. 31. keihmvmezc F, F mercm v, Y mznehc k, nmjmoc F, Bemrn s, Bmj ehac H, e c ma. efeec o mceerma mrececy r mceerma ieeu mrn o ecma e en oa n e ecci a. aicm-P me P iyehcmcey. 2014;6(4):435-9. 32. du MC, Ouy mre YQ, nce XF, Humre Y, renncre sr. efeeci o hyicema ee eeecie nuecre eeermrey r mceerma mrn cromrc uce ei cr vee ecehc mrn oeie e eermrc er: a e cm-mrmayici. Bcech. 2019;46(2):211-21. 33. Mmee -Mma ii er, smee re g, dc Mmiec d, dc T mi M, Beeeheaam v. eeeeecie nuecre eeermrey mrn ecik o eecee ocech cr vee ecehc mrn oeie er: m iyice mcce eevce mrn ecm-mrmayici o emrn czen e rce aaen cecmai. aecm Ooic ec gyree a semrn. 2017;96(3):263-73. 34. a eecemr C aaeee o Ooic ecececmri mrn gyree a ecici. C ccc ee crc r: hyicema meccvccy mrn ee eeecie nuecre e eermrey mrn che ic mecu eec n. Ooic ec gyree a. 2015;126(6):135-42. 35. Tcrcui ra, Cmhcaa ag, Cmne WT. i mec o hyicema meccvccy nuecre eeermrey r oicecece uce ei cr oeie er. J s eci Men Phyi Fccreii. 2017;57(5):652-9. 36. Ch c J, Fuku k m Y, lee JH. The ef eeci o hyicema meccvccy mrn hyicema meccvccy aui ncec crceevercc ri r o ny ecehc cr vee ecehc e oeie er h mee eeermrc e cr ic mecu : m iyice mcce eevce mrn ecm-mrmayici o emrn czen e rce aaen cecmai. Pe ev Men. 2013;56(6):351-64. 37. vcne šek M, B k ma vecmčrck e, Šće mr vcć d, Ž eue l, vcne šek n, Mešk M, e c ma. Pec e čcam z m ceaeir nejmvr ic r iečrce. znemv v eicr. 2015;84:87-98. 38. Bmemkmc r, luecm a, rucz Jr. reicicmree ee eeecie cemcrcre nuecre eeermrey mrn re o er’i ocech icze: m emr- n cien e rce aaen cecma. irc J Ooei. 2009;33(9):1048-57. 39. suc z, gecveaa rM, d nn JM. arcermcma eeeeecie c c e ve uce ei cr vee ecehc e oeie er: a iyice mcce e evce . aecm Ooic ec gyree a semrn. 2012;91(5):538-45. 40. Hmyei l, Beaa r, r oi r s, P ic r l; UPBeaT C ri eccu . aii ecmcc r oe c eer hyicema meccvccy cr oeie eeermrc er mrn e eermrey uce ei: che UPBea T ca c icuny. arr nuce Me cmo. 2014;64(3-4):239-46. 41. smrc i ia, scecr r, Fuehi sC, duremr BB, rcoece JP, ke ef lr, e c ma. aee oce eeeeecie mrn iuo mec ma ourecc rma em meccy cr vee ecehc eeermrc er: m emrn czen cecma. Ooic ec gyree a. 2005;106(2):243-9. 42. P ic r l, Beaa r, Ce kee H, Fayrr aC, g noeey kM, g f l, e c ma.; UPBeaT T ecma C ri eccu . efeec o m oehm- vc uema crceevercc r cr oeie eeermrc er (che UPBea T icuny): m uacceercee, emrn cien e rce aaen cecma. lmre ec dcmoecei ern eecr a. 2015;3(10):767-77. 43. rermuac kM, nøeemmen k, ncami l, Cmeaier eM, C ec ei d, Pe yni O, e c ma. The T eemc erc o Ooeie Pe eermrc W er (TOP) icuny: m emrn czen e rce aaen cecma o che efeec o hyicema meccvccy crceevercc r miiei- ien oy en ecee cch e cch uc ncecmey crceevercc r cr oeie eeermrc er. a J Ooicec gyree a. 2014;210(2):134.e1-9. 44. du MC, Ouy mre YQ, nce XF, Humre Y, renncre sr. efeeci o hyicema ee eeecie nuecre eeermrey r mceerma mrn cromrc uce ei cr vee ecehc mrn oeie e eermrc er: a e cm-mrmayici. Bcech. 2019;46(2):211-21. 45. d nn JM, gecveaa rM, Ce chee Ca, r ocri r Js. arcermcma crceevercc ri o e vee ecehc e oeie eeermrc er: m iyic e mcce e evce o emrn cien cecmai. BJOg. 2010;117(11):1316-26. 46. eaac cc-smae kJ, Bmere cc CT, smae C. eeeeecie crceevercc ri o e ecehc mrmee erc nuecre eeermrey mrn u c 1 ye me ic mecu m re r e ma ecehc, vee ecehc mrn oeie er: m iyice mcce eevce mrn ecm-mrmayici. Be J s eci Men. 2015;49(20):1336-42. 47. Ore MJ, gueaoc kJ, Hurc ee T, W maa mr ke, F uercee P a, ne rhm JP. su eevcien h e-omien ee eeecie my mccerumce che neeacre o eaue ie c aeemre e cr oeie e eermrc er. dcmoe cei Mecmo. 2009;35(5):418-21. 48. Cmaam my lk, C anccz PB, Byere nM, lcre n Be, r amrni iJ, F eee ft k, ec ma.; BaMBinO ge u . Pe e- vercc r o eeicmcc rma ncmoecei: oemicocaccy ciiuei o e mr ee eeecie crceevercc r cr oeie eeermrc er. dcmoecei Cme e. 2010;33(7):1457-9. 234 znemv v eicr | me ee – m eca 2020 | l ecrck 89 rePrOdUkCiJa čl Oveka 49. vcrcee Ca, Jerier dM, Oveier P, Beek-nceaier H, Jøee erier Js. The lcP (lco eicyae cr Pe eermrey) icuny: m emrn czen e rce aaen cecma o acoeicyae crceevercc r cr 360 oeie eeermrc er. dcmoecei Cme e. 2011;34(12):2502-7. 50. P ic r l, Becaey al, Bmee s, Beaa r, Ce kee H, C e r k, ec ma. devea cre m e aee crceevercc r o e ncec mrn meccvccy oehmvc ue ehmree cr oeie eeermrc er (che UPBea T cecma); miieii erc o oehmvc uema ehmree mrn e e eii ev maumcc r cr m ca c emrn cien e rce aaen cecma. BMC Pe eermrey Chcanocech. 2013;13(1):148. 51. Bcii r M, aa éemi n, duoeeire ss, r occmcaae J, rhému e C, Buj an e, ec ma. a 12-Week eeeeecie Pe eem o e Pe eermrc W er cch Ooeiccy c i e ve Phyicema aeccvccy leveai: ar O er rmrn cien Pe eac crmey scuny. Pl s Ore. 2015;10(9):e0137742. 52. dekkee ncceec M, Bmee ecc Hl, derry kJ, Meircye e Hd, Cmaam my lk; BaMBinO ee u . eeeeecie cr eeermr- ey n ei r c macee eeicmcc rma ecehc emcr, MCP-1 e ae ccr cr oeie er. auic n z J Ooic ec gyrmee a. 2015;55(1):27-33. 53. dmay n, F meeer M, Meke mccre a, Oʼkeaay r, scm aec r M, Tueree MJ. a Mencemaay su eevcien Pe eermrey eeeeec- ie irc eevercc r cr Ooeie W er: a rmrn czen C rce aaen T ecma. Ooic ec gyree a. 2017;130(5):1001-10. 54. rermuac kM, Cmeaier eM, Hæneeinma s, ncami l, seehee nJ, eueer-Oaier J, e c ma. i mec o acoeicyae crceever- cc r o e oeie er nuecre eeermrey r mceerma ecmo ace mrn croam mc ey mekeei. irc J Ooei. 2017;41(4):598-605. 55. F eee ft kF, r amrni iJ, Byere nM, Meircye e Hd, Cmaam my lk; BaMBinO ee u . eeeeecie cr oeie eeermrc er: che e ae o i ecma omec ei, aco eicyae mrn e eermrey iy c i. BMC Pe eermrey Chcanocech. 2011;11:4. 56. sy ri d ri d, Hmuieroami Ha. W er ’i ee eeecie oeaceoi mrn oehmvc ei nuecre chece eeermrey mrn ic mecu . J Mcn co eey W eri He mach. 2004;49(2):138-44. 57. Bmiiecc dr. vmacnccy mrn eeacmocaccy ciiuei cr ojeeccve rcc ecre o hyicema meccvccy. rei Q eeeee s ec . 2000;71(2):s30-6. 58. M cc am MF, gce ue i, gemcc r r, Hm rn Ja, Hmraey a, Hmeeci s, e c ma. nuceccc r mrn ee eeecie eeverc eeeeii ecehc emcr cr vee ecehc e eermrc er. Men sec s eci ee eee. 2010;42(2):265-72. 59. zmv eiky gs, l re ld. ee eeecie eucneacrei cr e eermrey: re eei eeccvei. s eci Men. 2011;41(5):345-60. 60. Huc a, Bmek l, lun ce s, gmencree P, severhuyier g, demr H, e c ma. lcoeicyae crceevercc r r ncec mrn ee eeecie eenueen eeeeiicve eeicmcc rma ecehc emcr cr eeermrc er urnee m emrn cien e rce aaen cecma. BJOg. 2012;119(1):70-7. 61. Cameii r iM, synijö g, Be yrhcanier J, Ceneeee er M, Je ii r a, nyiceö F, e c ma. Wecehc emcr eeicececc r o e oeie e eermrc er: m emie-e rce a crc eevercc r icuny. BJOg. 2008;115(1):44-50.