Physical activity before and during pregnancy: A cohort study

Abstract

Objective
To estimate physical activity (PA) in healthy women before and during pregnancy and to evaluate the features associated with moderate PA (MPA).

Methods
A prospective cohort study was conducted on women selected 14 weeks of pregnancy during 2013–2015 in primary public health service centers in southern Spain. Type, duration, and frequency of PA (IPAQ questionnaire in first, second, and third trimesters [T1, T2, T3]) were measured. Variables associated with MPA were evaluated using multiple logistic regressions controlling for age, pre‐pregnancy obesity, level of education, number of living children, pre‐pregnancy PA, and adherence to Mediterranean diet (AMD).

Results
Out of 463 women, MPA was estimated in 64% pre‐pregnancy, and 54%, 61%, and 59% in T1, T2, and T3, respectively. MPA was associated with greater AMD in T2 (adjusted odds ratio [aOR] 1.17, 95% confidence interval [CI] 1.04–1.33) and T3 (aOR 1.16, 95% CI 1.02–1.31), previous PA (aOR 13.5, 95% CI 8.12–22.5 in T1; aOR 2.61, 95% CI 1.72–3.96 in T2; aOR 2.59, 95% CI 1.65–4.05 in T3), and pre‐pregnancy obesity (aOR 2.97, 95% CI 1.28–6.89 in T1; aOR 2.69, 95% CI 1.23–3.60 in T3).

Conclusion
PA decreased at the beginning of pregnancy, but compliance remained over 50%. MPA was associated with diet, pre‐pregnancy PA, and obesity.

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doi: 10.1002/IJGO.13387
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Article type : Clinical Article (IJGO)
CLINICAL ARTICLE
Physical activity before and during pregnancy: A cohort study
M. R. Román-Gálvez1,2, Carmen Amezcua-Prieto1,3,4,*, I. Salcedo-Bellido1,3,4, R..
Olmedo-Requena1,3,4, J. M. Martínez-Galiano3,5, K. S. Khan1,6, A. Bueno-
Cavanillas1,3,4
1Department of Preventive Medicine and Public Health, University of Granada,
Granada, Spain
2Unidad de Gestión Clínica Churriana de la Vega, Andalusian Health Service,
Granada, Spain
3Consortium for Biomedical Research in Epidemiology and Public Health
(CIBERESP), Madrid, Spain
4Instituto de Investigación Biosanitaria ibs.GRANADA, Complejo Hospitales
Universitarios de Granada/Universidad de Granada, Granada, Spain
5Department of Nursing, University of Jaén, Jaén, Spain
6Women’s Health Research Unit, Barts and the London School of Medicine and
Dentistry, Queen Mary University of London, London, UK
*Correspondence
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Carmen Amezcua-Prieto, Department of Preventive Medicine and Public Health,
Tower A, Floor 8, Room 06. Faculty of Medicine, Avenida de la Investigación, 11,
University of Granada 18016, Granada, Spain.
Email: carmezcua@ugr.es
Keywords
Physical activity; Pregnancy; Recommendations; Sociodemographic factors;
Trimester
Synopsis
Moderate physical activity (MPA) was achieved by >50% of women during
pregnancy. MPA was associated with healthy diet, pre-pregnancy obesity, and
greater PA before pregnancy.
ABSTRACT
Objective: To estimate physical activity (PA) in healthy women before and during
pregnancy and to evaluate the features associated with moderate PA (MPA).
Methods: A prospective cohort study was conducted on women selected 14 weeks
of pregnancy during 2013–2015 in primary public health service centers in southern
Spain. Type, duration, and frequency of PA (IPAQ questionnaire in first, second,
and third trimesters [T1, T2, T3]) were measured. Variables associated with MPA
were evaluated using multiple logistic regressions controlling for age, pre-pregnancy
obesity, level of education, number of living children, pre-pregnancy PA, and
adherence to Mediterranean diet (AMD).
Results: Out of 463 women, MPA was estimated in 64% pre-pregnancy, and 54%,
61%, and 59% in T1, T2, and T3, respectively. MPA was associated with greater
AMD in T2 (adjusted odds ratio [aOR] 1.17, 95% confidence interval [CI] 1.04–1.33)
and T3 (aOR 1.16, 95% CI 1.02–1.31), previous PA (aOR 13.5, 95% CI 8.12–22.5
in T1; aOR 2.61, 95% CI 1.72–3.96 in T2; aOR 2.59, 95% CI 1.65–4.05 in T3), and
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pre-pregnancy obesity (aOR 2.97, 95% CI 1.28–6.89 in T1; aOR 2.69, 95% CI
1.23–3.60 in T3).
Conclusion: PA decreased at the beginning of pregnancy, but compliance
remained over 50%. MPA was associated with diet, pre-pregnancy PA, and obesity.
1 INTRODUCTION
Physical activity (PA) during pregnancy is beneficial for both the mother and child. It
is associated with cardiovascular health [1], a decrease in the risk of chronic
disease [2], reduction in maternal and fetal weight gain, reduction in pre-term
delivery, and control of gestational diabetes and hypertension [3]. Most guidelines
include recommendations to encourage pregnant women without complications to
perform moderate intensity PA (MPA) during pregnancy [4–6]. Guidelines
recommended at least 150 minutes spread out during the week or at least 20–30
minutes each day [7]. The Spanish Society of Obstetrics and Genecology (SEGO)
guideline is based on the one from the American College of Obstetrics and
Gynecology (ACOG) [8].
It is estimated that just under one-third of pregnant women undertake PA during
pregnancy [9, 10]. PA has been associated with level of education and age [9, 11]
but these observations have a risk of bias and are imprecise [1, 2, 9–18]. Only two
studies have covered pre-pregnancy and pregnancy PA [12, 16]. In the first one, the
sample size was quite small, 236 women [12], and in the other, the women had
high-risk pregnancies [16]. Therefore, there is a need for a reliable evaluation of PA,
according to the recommendations in healthy pregnant women, during the course of
pregnancy. The aim of the present study was to estimate PA before and during
pregnancy in a cohort of healthy women and to identify the characteristics
associated with MPA of at least 30 minutes 5 days a week.
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2 MATERIALS AND METHODS
A prospective cohort study was planned, conducted, and analyzed with robust
methods so as to permit reporting in compliance with STROBE guidelines [19].
The study sample consisted of pregnant women followed up for antenatal care from
February 2013 to August 2015 in primary public health service centers in Andalusia,
Spain (in the provinces of Granada, Jaén, Huelva, and Seville, from both rural and
urban locations). In the health centers, the midwives voluntarily participated in the
collection of data.
The primary care centers were chosen based on the collaboration of the midwife
attached to it in recruiting women. A total of 47 health centers were selected; the
largest of them assists a population of 33 894 inhabitants and the smallest serves
870 inhabitants. In total, they cover a population of 487 796 inhabitants. This
information was retrieved from the Andalusian Health Service in 2017. Then,
67.18% (n=348) of the sample of pregnant women were recruited in urban health
centers, located in populations of over 25 000 inhabitants, while the remaining
32.82% (n=170) were recruited in rural health centers, located in populations of less
than 25 000 inhabitants. No significant differences (P<0.05) were found in the
sociodemographic characteristics of both groups of women (data not shown).
The included women met the following selection criteria: a singleton healthy
pregnancy; no previous diseases that alter diet or physical activity, such as
diabetes, hypertension, heart failure, respiratory, moderate or severe renal or
hepatic disease, or neurological or musculoskeletal diseases that influence mobility;
booked for antenatal care before the 14th week of pregnancy; no linguistic or
cognitive barriers that affect communication; and agreeing to participate in the
study. Both those women who did not meet these criteria at the time of recruitment
and those who had a miscarriage during follow-up were excluded.
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Midwives identified eligible women at their first antenatal visit. The required data
were collected by personal interview (first occasion) and telephone follow-up in the
three trimesters of pregnancy (the first trimester [T1] before 14 weeks of pregnancy,
the second trimester [T2] around 24±2 weeks of pregnancy, and the third trimester
[T3] after 32 weeks of pregnancy). In T1, data were collected relating to the initial
weeks of pregnancy and the pre-pregnancy period (4–6 months before pregnancy).
In the T2 and T3 interviews, information about the same data recorded in the T1
interview was requested, but this time referring to T2 and T3.
The measurements included: (1) sociodemographic variables: age (18–25, 26–30,
31–35, >35), level of education (primary, secondary, university), social class
according to the classification of the Spanish Society of Epidemiology (I high, II
medium-high, III medium, IV medium-low, V low) (20), work outside the home (no,
yes); (2) obstetric variables: number of previous children (0, 1, ≥2) and number of
previous abortions (0, 1, ≥ 2); (3) anthropometric variables: height and pre-
pregnancy weight, body mass index (BMI, calculated as weight in kilograms divided
by the square of height in meters and reclassified as low [<25 kg/m2], overweight
[25–29.9 kg/m2], or obese [≥30 kg/m2] according to the criteria of the Spanish
Society for the Study of Obesity [21]); (4) adherence to a Mediterranean diet (AMD)
was assessed before pregnancy and in each trimester of pregnancy according to
the adapted PREDIMED index (excluding intake of wine), with a score of 0–13,
where a higher score indicates greater adherence [22]; and (5) consumption of
tobacco during pregnancy.
Physical activity
The International Physical Activity Questionnaire (IPAQ) was used to capture the
pre-pregnancy and pregnancy PA for the three trimesters of pregnancy (T1, T2, and
T3) into low, moderate, and high PA profiles [23]. Total, vigorous, moderate, and
walking metabolic equivalent task (MET)-minutes per week were calculated
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according to the IPAQ questionnaire instructions [23]. Women were classified
according to compliance with PA recommendation, i.e. performing at least 15
minutes of vigorous PA (VPA) or 30 minutes of moderate aerobic PA (MPA) for a
minimum of 5 days per week [4, 24]. The total sedentary time was calculated in
hours/week from the last answer of the IPAQ questionnaire, before pregnancy and
in each trimester of pregnancy. Finally, MET-minutes/week of MPA, VPA, and
walking were estimated, multiplying days of activity type by minutes per day of that
activity and by their intensity: 8 MET for VPA, 4 MET for MPA, and 3.3 MET for
walking time. Total MET-minutes/week is the sum of the three categories above
[25].
Statistical analysis
The sample size was estimated a priori – in the “Lifestyles in pregnancy cohort”
project—based on the expected prevalence of the main lifestyle choices (diet,
physical activity, smoking) with a 5% type I error and 90% for power. For example,
in a previously published paper, considering the less favorable option of a pre-
pregnancy smoking prevalence of 21% and 15% during pregnancy, a minimum of
363 women were needed to detect significant changes. Estimating a loss
percentage of 15%, 428 women in total were needed. To estimate the potential
sample size for the measurement of PA in pregnancy, accepting an alpha risk of
0.05, a beta risk of 0.2 in a two-sided test, and a drop-out rate of 20%, 239 women
are necessary to recognize a difference in compliance with PA greater than or equal
to 10% between different time periods during pregnancy. A proportion of compliance
with PA recommendations in the reference group has been estimated to be 0.4.
Descriptive statistics mean and standard deviation (SD) were calculated for
continuous variables and number (percentage) for categorical variables. McNemar
tests were used to compare women who met the PA guideline to those who did not
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for categorical variables and adjusted repeated measures ANOVA for continuous
variables. ANOVA was adjusted for age, AMD, level of education, and number of
previous living children.
Crude (cOR) and adjusted odds ratios (aOR) and their 95% confidence intervals
(CI) were estimated by multiple logistic regression models to evaluate the
relationship of variables related to compliance with MPA recommendations
(dependent variable). The independent variables were age, socioeconomic level,
level of education, number of previous living children, BMI, precedent miscarriages,
smoking, AMD, and previous compliance with PA according to the stage in
pregnancy, for example, pre-pregnancy PA if the woman was in the first trimester of
pregnancy or compliance to first trimester PA if the woman was in the second
trimester. To control for confounding variables, those variables that changed the PA
coefficient by more than 10% were retained in the logistic models. Finally, the model
was adjusted for age, maternal level of education, pre-pregnancy BMI, number of
previous living children, previous compliance with PA, and AMD. P<0.05 was
considered statistically significant. Data analyses were performed using statistical
software Stata14.0. There was no formal involvement of the patients in the design
and analysis of the research. The funder of the study had no part in the analysis or
writing of this manuscript at any stage.
The study protocol adhered to the Declaration of Helsinki of the World Medical
Association and was approved by the Ethics Committee of Granada (C-24-2013).
The included women provided written informed consent. All data collected were
treated in accordance with Spanish legislation on the protection of personal data
and stored in an electronic database without identifiers.
3 RESULTS
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Of the 518 pregnant women selected and interviewed at T1, 32 (6.17%) had an
early miscarriage, 463 (89.38%) were followed up until T2 and/or T3, 50 (9.65%)
were lost to follow-up in T2. From the second to the third interview (T3), there was
33 (6.37%) losses. However, 26 (5.01%) women lost at T2 were included in T3 (Fig.
1).
Table 1 shows the characteristics of the women in the present cohort. The mean
age was 31.24±5.17 (range 16–47 years). The majority of the women were Spanish
(n=440, 95%; data not shown), with secondary or university education (n=384,
82.93%) and paid work (n=327, 70.62%). At the beginning of pregnancy, the
average BMI was 24.59±4.65: 128 (27.6%) mothers were overweight and 45 (9.7%)
were obese. The AMD score increased from 7.70±1.92 in T1 to 7.96±1.85 in T3
(data not shown).
Pre-pregnancy and pregnancy physical activity
Table 2 shows the distribution of PA according to IPAQ classification (low,
moderate, and high PA profiles), the compliance with PA recommendation, energy
consumption (MET-minutes/week), and sedentary time (hours/week) before and in
each trimester of pregnancy.
Stratifying women by IPAQ categories, the percentage of pregnant women
classified with low PA increased in early pregnancy from 182 (39.3%) in the pre-
pregnancy period to 240 (51.8%) at T1 and stayed at around 217 (50%) at T2 and
T3 (49.7% and 50.7%, respectively; P<0.001).
The percentage of women who complied with the PA recommendations decreased
from the pre-pregnancy stage (n=297, 64.4%) to T1 (n=252, 54.5%; P<0.050) and
was enhanced in T2 (n=268, 61.9%; P=0.050).
With the progression of pregnancy, the total energy expenditure decreased in each
trimester compared to the pre-pregnancy period (P<0.001). This was mainly due to
MPA and VPA MET-minutes/week. The estimated walking MET-minutes/week did
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not show any significant change. Finally, sedentary time increased throughout
pregnancy (P<0.001).
Factors related to MPA above the 450 MET-minute/week threshold
Table 3 shows the factors related to compliance with PA recommendations from the
pre-pregnancy period throughout the pregnancy. The more consistent finding is the
positive influence of previous PA and quality of diet, although AMD was not
associated with compliance with PA in T1. Obesity was related to compliance with
PA in T1 (aOR 2.97, 95% CI 1.28–6.89) and T3 (aOR 2.69, 95% CI 1.23–3.60) but
not in T2. Age and level of education were associated with compliance with PA only
in T1. Low socioeconomic class was also associated to lower compliance with PA
recommendations at the beginning of pregnancy; however, this effect disappeared
in T2 and was reversed in T3, where it was only significant for those in social class
IV (aOR 2.31, 95% CI 1.01–2.59).
4 DISCUSSION
The results of the present study showed that approximately two-thirds of healthy
pregnant women achieve enough PA according to recommendations [4, 24].
However, PA energy expenditure decreases significantly from pre-pregnancy to T3
(more than 40%), mainly because there was a decrease in MPA and VPA. At the
same time, an increase in sedentary time was found. These three facts may be due
to the deep-rooted belief that pregnant women should “take care of themselves by
taking rest” or at least by doing less PA than they did before pregnancy. The main
variables associated with MPA were AMD as well as previously performed PA and
pre-pregnancy obesity.
The validity of the present findings depends on the strength and limitations of
methods, which should be understood first before assessing their implications.
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The present study has several strengths. A prospective study of healthy pregnant
women was designed with the same interviewer collecting the data from the three
trimesters of pregnancy, thereby minimizing the variation that may arise from
multiple interviewers. The planned sample size was almost reached, with the
inception of the cohort of women before 14 weeks of pregnancy. All the healthcare
centers chosen were included in the public healthcare service of Andalusia, where
approximately 99% of the pregnant population receives obstetric care. Therefore, it
is believed that the present sample is representative of healthy pregnant women.
Besides, less than 20% of data was missing, minimizing attrition bias.
The present study also had some limitations. The recall of the participants could be
identified as questionable regarding its reliability. Some misclassification could exist
due to the bias of desirability when the women were interviewed. There was the
possibility of systematic bias (either over or under) reporting of PA both at different
points and between subgroups of women, particularly with respect to BMI or degree
of obesity. The main limitation of the model used for repeated measurements is the
requirement for complete and balanced data. However, it was considered that the
results were valid, because before applying the model the following factors were
verified: (1) the independence of the responses between the different participants in
the sample; (2) the distribution of the multiple dependent variables was normal
multivariate; and (3) the verification of the homogeneity of the covariance matrices
and the sphericity of the common covariance matrix.
A slight decrease was found in compliance with PA recommendations at the
beginning of pregnancy (T1), but there was a recovery in T2. The percentage of
women who complied with the PA recommendations through pregnancy (more than
50%) is slightly higher than in other studies: for example, 45% during pregnancy in
the United States [16] or 48.8% at 18 and 32 weeks of pregnancy in the UK [15]. In
another study of 46 pregnant women from the state of Iowa, where PA was
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monitored for 7 days, the compliance with PA recommendations during pregnancy
was pretty similar: 46% at 18 weeks of pregnancy and 28% at 35 weeks of
pregnancy [13]. This means that in resource-limited countries, the data regarding
compliance with PA during pregnancy are similar. The lower figures refer to
Brazilian women, 13.6% in T1, 17.8% in T2, and 13.4% in T3 [10].
Only one report of compliance with PA recommendations in healthy pregnant
women from pre-pregnancy to the end of pregnancy was found: a prospective
cohort study conducted recently in Italy, with a sample of 177 women of normal
weight and 59 overweight/obese women [12], where compliance with the PA
threshold increased in women of normal weight from 25% in T1 to 45% in T2,
declining to 37% in T3. Again, compliance with PA recommendations is higher in
T2. However, compliance in overweight or obese women was still lower, at 20%,
23%, and 15%, respectively.
When only leisure time physical activity (LTPA) is considered in the evaluation of
PA, instead of the combination of different domains (occupational, displacement, or
homework/caregivers), compliance is even lower, which may be indicative that “the
care of the pregnant woman through rest” is a belief that extends beyond Spain.
This is why the PA that is maintained is necessary for work or household
responsibilities, discarding the PA carried out on purpose, that is, in leisure time.
Thus, bearing in mind LTPA during pregnancy exclusively, only 7.1% of pregnant
Puerto Rican women residing in Massachusetts [16] or 34% of pregnant Asian
women [17] complied with the recommendations. In the present study, all PA was
considered when measuring the recommendations, not only the LTPA. This is why
the present results were higher.
Is spite of relatively high rates of compliance with PA, mainly due to walking, energy
expenditure decreases at the same time that sedentary time increases with the
progression of the pregnancy. The level of sedentariness in pregnancy observed in
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the present study was similar to that in other studies, such as the one carried out in
Singapore [17] where hours of sedentary time increased from 56 hours/week before
pregnancy to 63 hours/week during pregnancy. Pregnant women from Iowa who
met PA guidelines at 35 weeks of pregnancy had significantly less sitting time
(P<0.005) than women who did not meet the guidelines [13].
Regarding the factors involved in meeting the PA recommendations, the positive
influence of previous PA habits has been previously observed [10, 14, 17, 26].
Some studies conclude, similar to the present study, that the strongest predictor of
PA in late pregnancy is PA before pregnancy [12, 14]. However, the present results
did not show less PA in overweight and obese pregnant women as was found by
Bacchi et al. [12]. On the contrary, obesity is positively associated with compliance
with PA in T1 and T3 probably because health professionals promote PA,
particularly in those women who need to control their weight. The effect of the
woman’s age is also controversial. A tendency was found towards decreased PA in
older women, whereas an inverse relationship was observed in Denmark [9]. Other
studies did not find any association between age and PA [16, 27]. The present study
did not find that a higher level of education of the woman was related to better
compliance with PA, contrary to other 10, 11]. Lastly, a positive association was
found between AMD and compliance with PA in T2 and T3.
Finally, professional counseling regarding PA in pregnancy in the participating
health centers and PA behavior depending on residence in urban or rural areas
were not measured.
Implication for practice
It is a fact that in pregnancy sedentarism increased, the total consumption of energy
decreased, and half of the pregnant women achieved the PA recommendations
according to the guidelines [4–7]. The need to educate the population about PA
during pregnancy is evident. Given that women at this stage of their life receive
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much advice from their environment—mainly from their mothers and relatives—
health education carried out in consultation/counseling may be insufficient, and it
could be adequate, timely, and convenient to involve the media in this task. These
campaigns will help to avoid the decrease in PA in T1—the period in which low
activity is performed—when the pregnant woman is just beginning to receive health
education.
5 CONCLUSION
PA decreases with pregnancy, it increases slightly in the second trimester, and
drops in the third trimester. Nevertheless, compliance with MPA guidelines remains
over 50%. MPA in pregnancy is related to dietary habits as well as pre-pregnancy
PA and obesity. Close to one in two women do not achieve the PA
recommendations. Thus, advice about PA is essential, especially at the beginning of
pregnancy.
Author contributions
All authors meet the criteria for authorship and have approved the final article. ABC,
RMRG, and CAP drafted the manuscript and conducted the statistical analysis.
RMRG designed the study and was involved in acquisition of data. ISB, ROR,
JMMG, and KSK critically revised the manuscript.
Acknowledgments
The authors thank the pregnant women and midwifes involved in the study. The
study was partially supported by a grant (PROY-PP 2015-01) from the University of
Granada.
Conflicts of interest
The authors have no conflicts of interest.
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References
1. Barakat R, Perales M, Garatachea N, Ruiz JR, Lucia A. Exercise during
pregnancy. A narrative review asking: what do we know? British journal of sports
medicine. 2015;49(21):1377-81.
2. Blaize AN, Pearson KJ, Newcomer SC. Impact of Maternal Exercise during
Pregnancy on Offspring Chronic Disease Susceptibility. Exercise and sport sciences
reviews. 2015;43(4):198-203.
3. Straughen JK, Sealy-Jefferson S, Bazydlo M, Helmkamp L, Misra DP.
Physical Activity and Risk of Preterm Birth in a Cohort of African American Women.
Women's health issues : official publication of the Jacobs Institute of Women's
Health. 2018;28(6):488-94.
4. ACOG Committee Opinion No. 650: Physical Activity and Exercise During
Pregnancy and the Postpartum Period. Obstetrics and gynecology.
2015;126(6):e135-42.
5. Evenson KR, Barakat R, Brown WJ, Dargent-Molina P, Haruna M, Mikkelsen
EM, et al. Guidelines for Physical Activity during Pregnancy: Comparisons From
Around the World. American journal of lifestyle medicine. 2014;8(2):102-21.
6. Mottola MF, Davenport MH, Ruchat SM, Davies GA, Poitras VJ, Gray CE, et
al. 2019 Canadian guideline for physical activity throughout pregnancy. British
journal of sports medicine. 2018;52(21):1339-46.
7. Evenson KR, Mottola MF, Artal R. Review of Recent Physical Activity
Guidelines During Pregnancy to Facilitate Advice by Health Care Providers.
Obstetrical & gynecological survey. 2019;74(8):481-9.
8. Obsteticia. SEdGy. Prenatal control of normal pregnancy. Prog Obstet
Ginecol. 2018;61(5):510-27.
Accepted Article

This article is protected by copyright. All rights reserved
9. Juhl M, Madsen M, Andersen AM, Andersen PK, Olsen J. Distribution and
predictors of exercise habits among pregnant women in the Danish National Birth
Cohort. Scandinavian journal of medicine & science in sports. 2012;22(1):128-38.
10. Nascimento SL, Surita FG, Godoy AC, Kasawara KT, Morais SS. Physical
Activity Patterns and Factors Related to Exercise during Pregnancy: A Cross
Sectional Study. PloS one. 2015;10(6):e0128953.
11. Amezcua-Prieto C, Olmedo-Requena R, Jimenez-Mejias E, Mozas-Moreno J,
Lardelli-Claret P, Jimenez-Moleon JJ. Factors associated with changes in leisure
time physical activity during early pregnancy. International journal of gynaecology
and obstetrics: the official organ of the International Federation of Gynaecology and
Obstetrics. 2013;121(2):127-31.
12. Bacchi E, Bonin C, Zanolin ME, Zambotti F, Livornese D, Dona S, et al.
Physical Activity Patterns in Normal-Weight and Overweight/Obese Pregnant
Women. PloS one. 2016;11(11):e0166254.
13. Di Fabio DR, Blomme CK, Smith KM, Welk GJ, Campbell CG. Adherence to
physical activity guidelines in mid-pregnancy does not reduce sedentary time: an
observational study. The international journal of behavioral nutrition and physical
activity. 2015;12:27.
14. Haakstad LA, Voldner N, Henriksen T, Bo K. Why do pregnant women stop
exercising in the third trimester? Acta obstetricia et gynecologica Scandinavica.
2009;88(11):1267-75.
15. Liu J, Blair SN, Teng Y, Ness AR, Lawlor DA, Riddoch C. Physical activity
during pregnancy in a prospective cohort of British women: results from the Avon
longitudinal study of parents and children. European journal of epidemiology.
2011;26(3):237-47.
Accepted Article

This article is protected by copyright. All rights reserved
16. Lynch KE, Landsbaugh JR, Whitcomb BW, Pekow P, Markenson G, Chasan-
Taber L. Physical activity of pregnant Hispanic women. American journal of
preventive medicine. 2012;43(4):434-9.
17. Padmapriya N, Shen L, Soh SE, Shen Z, Kwek K, Godfrey KM, et al.
Physical Activity and Sedentary Behavior Patterns Before and During Pregnancy in
a Multi-ethnic Sample of Asian Women in Singapore. Maternal and child health
journal. 2015;19(11):2523-35.
18. Poyatos-León R, Sanabria-Martínez G, García-Prieto JC, Álvarez-Bueno C,
Pozuelo-Carrascosa DP, Cavero-Redondo I, et al. A follow-up study to assess the
determinants and consequences of physical activity in pregnant women of Cuenca,
Spain. BMC public health. 2016;16:437.
19. von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke
JP. The Strengthening the Reporting of Observational Studies in Epidemiology
(STROBE) Statement: guidelines for reporting observational studies. International
journal of surgery (London, England). 2014;12(12):1495-9.
20. Una propuesta de medida de la clase social. Atención Primaria.
2000;25(5):350-63.
21. Salas-Salvadó J, Rubio MA, Barbany M, Moreno B, de la Seedo* GC.
Consenso SEEDO 2007 para la evaluación del sobrepeso y la obesidad y el
establecimiento de criterios de intervención terapéutica. Medicina Clínica.
2007;128(5):184-96.
22. Martinez-Gonzalez MA, Garcia-Arellano A, Toledo E, Salas-Salvado J, Buil-
Cosiales P, Corella D, et al. A 14-item Mediterranean diet assessment tool and
obesity indexes among high-risk subjects: the PREDIMED trial. PloS one.
2012;7(8):e43134.
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23. Craig CL, Marshall AL, Sjostrom M, Bauman AE, Booth ML, Ainsworth BE, et
al. International physical activity questionnaire: 12-country reliability and validity.
Medicine and science in sports and exercise. 2003;35(8):1381-95.
24. Services DoHaH. Physical Activity Guidelines Advisory Committee. Scientific
Report Washington, DC, Services DoHaH; 2018.
25. Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett DR, Jr., Tudor-
Locke C, et al. 2011 Compendium of Physical Activities: a second update of codes
and MET values. Medicine and science in sports and exercise. 2011;43(8):1575-81.
26. Hegaard HK, Damm P, Hedegaard M, Henriksen TB, Ottesen B, Dykes AK,
et al. Sports and leisure time physical activity during pregnancy in nulliparous
women. Maternal and child health journal. 2011;15(6):806-13.
27. Santos PC, Abreu S, Moreira C, Lopes D, Santos R, Alves O, et al. Impact of
compliance with different guidelines on physical activity during pregnancy and
perceived barriers to leisure physical activity. Journal of sports sciences.
2014;32(14):1398-408.
FIGURE LEGEND
Figure 1. Flow chart of the cohort of pregnant women. Abbreviations: GW, weeks of
gestation; T1, first trimester; T2, second trimester; T2, third trimester.
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Table 1. Demographic description and lifestyles of the study cohort (n=463).a
Level of education
Primary
79 (17.06)
Secondary
187 (40.38)
University
197 (42.55)
Work outside home
Yes
327 (70.62)
No
136 (29.37)
Socioeconomic class
High/Middle–High (I–II)
157 (33.91)
Middle (III)
90 (19.44)
Low/Middle–Low (IV–V)
216 (46.64)
Number of living children
0
239 (51.61)
1
199 (42.99)
≥2
25 (5.39)
Miscarriage
0
338 (73.0)
1
97 (21.0)
≥2
28 (6.0)
Pre-pregnancy BMI b
Normal weight
287 (61.98)
Overweight
128 (27.64)
Obese
45 (9.71)
Unknown
3 (0.64)
Smokers during pregnancy
65 (14.0)
Age (years)
31.24±5.17
AMD
7.70±1.92
Abbreviations: AMD, adherence to the Mediterranean diet; BMI, body mass index.
a Values are given as number (percentage) or mean and standard deviation.
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b Low/normal weight <25 kg/m2; overweight 25–29.9 kg/m2; obesity ≥30 kg/m2.

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Table 2. Physical activity and compliance with PA recommendations during
pregnancy.a
Pre-
pregnancy
(n=463)
T1 (n=463)
T2 (n=436)
T3 (n=429)
P value
Physical activity
(IPAQ)
Low PA b
182 (39.3)
240 (51.8)
217 (49.7)
217 (50.7)
< 0.001
c,d,e,f
Moderate PA g
239 (51.6)
201 (43.4)
213 (48.8)
207 (48.3)
0.001 c,f
High PA h
42 (9.0)
22 (4.7)
6 (1.3)
4 (0.9)
<0.001
c,d,e,f
0.001 f,i
PA
recommendations j
297 (64.4)
252 (54.5)
268 (61.9)
253 (59.1)
<0.001 c,f
<0.050 f,i
PA energy
consumption
Total MET-min/week
1368±1705
1018±2536
845±755
789±654
<0.001 k
Walking MET-
min/week
673.8±737.7
735.3±2393.8
685.2±556.1
695.6±578.3
0.292 k
Moderate MET-
min/week l
440.4±983.5
249.7±816.9
152.3±507.5
93.5±297.4
<0.001 k
Vigorous MET-
min/week
253.4±987.9
33.5±359.3
10.5±136.5
0±0
<0.001 k
Sedentarism
Hours/week
29.04±21.47
35.47±23.55
33.64±20.45
35.93±20.84
<0.001 k
Abbreviations: ACOG, American College of Obstetricians and Gynecologists;
MET, metabolic equivalent task; PA, physical activity; T1, first trimester; T2,
second trimester; T3, third trimester.
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a Values are given as number (percentage) or mean ± standard deviation.
b Requirements for moderate or high not meeting.
c Pre-pregnancy with T1.
d Pre-pregnancy with T2.
e Pre-pregnancy with T3.
f McNemar test.
g Meeting any of the following: (1) 3 or more days of vigorous PA for at least 20
minutes/day; (2) 5 or more days of moderate PA and/or walking for at least 30
minutes/day; (3) 5 or more days of any combination of walking, moderate PA, or
vigorous PA reaching a total physical activity of at least 600 MET-min/week.
h Meeting any of the following: (1) 3 or more days of vigorous PA reaching a total
PA of at least 1500 MET-min/week; (2) 7 or more days of any combination of
walking, moderate PA, or vigorous PA reaching a total physical activity of at least
3000 MET-min/week.
i T1 with T2.
j ACOG PA recommendations: performing at least 30 minutes of moderate
aerobic physical activity, most days or every day of the week.
k ANOVA for related samples.
l Walking not included.
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Table 3. Factors associated with compliance with PA recommendations during pregnancy.
Pre-pregnancy
T1
T2
T3
cOR (95%
CI)
aOR a (95%
CI)
cOR (95% CI)
aOR a (95%
CI)
cOR (95%
CI)
aOR a (95%
CI)
cOR (95%
CI)
aOR a (95%
CI)
Age (years)
18–25
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
26–30
1.97 (1.01–
3.82)
1.90 (0.95–
3.80)
0.69 (0.35–
1.34)
0.37 (0.15–
0.85)
0.98 (0.49–
1.99)
0.97 (0.45–
2.04)
1.26 (0.64–
2.46)
1.08 (0.50–
2.32)
31–35
1.21 (0.65–
2.26)
1.24 (0.63–
2.41)
0.53 (0.28–
1.00)
0.33 (0.14–
0.74)
0.75 (0.38–
1.47)
0.83 (0.40–
1.74)
1.21 (0.63–
2.29)
0.95 (0.45–
2.01)
>35
1.61 (0.79–
3.26)
1.68 (0.77–
3.66)
0.53 (0.26–
1.08)
0.27 (0.10–
0.69)
0.63 (0.30–
1.32)
0.76 (0.33–
1.75)
1.10 (0.54–
2.25)
0.83 (0.35–
1.95)
Level of
education
Primary
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
Secondary
1.00 (0.57–
1.73)
0.93 (0.52–
1.66)
1.42 (0.83–
2.41)
2.04 (1.06–
3.94)
1.11 (0.63–
1.95)
0.89 (0.49–
1.63)
0.77 (0.44–
1.35)
0.69 (0.37–
1.30)
University
1.03 (0.59–
1.78)
0.80 (0.43–
1.50)
1.03 (0.61–
1.74)
1.67 (0.84–
3.32)
1.11 (0.64–
1.94)
0.80 (0.43–
1.51)
1.45 (0.83–
2.54)
1.37 (0.70–
2.67)
Socioeconomic
class
I–II
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
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III
0.87 (0.50–
1.49)
0.89 (0.46–
1.73)
0.80 (0.47–
1.35)
0.43 (0.20–
0.92)
0.87 (0.50–
1.51)
0.72 (0.36–
1.46)
0.99 (0.57–
1.71)
2.10 (0.96–
4.62)
IV
0.99 (0.60–
1.62)
0.99 (0.49–
1.99)
0.87 (0.54–
1.41)
0.35 (0.15–
0.78)
0.75 (0.45–
1.25)
0.67 (0.32–
1.40)
0.84 (0.51–
1.38)
2.31 (1.01–
5.29)
V
1.02 (0.59–
1.76)
1.11 (0.50–
2.45)
1.08 (0.64–
1.82)
0.46 (0.19–
1.10)
0.98 (0.56–
1.71)
0.83 (0.36–
1.88)
0.96 (0.55–
1.67)
2.47 (0.98–
6.23)
Previous children
0
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1
0.72 (0.48–
1.06)
0.68 (0.44–
1.04)
0.97 (0.66–
1.42)
1.41 (0.87–
2.28)
0.65 (0.43–
0.98)
0.64 (0.42–
1.00)
0.65 (0.44–
0.98)
0.70 (0.44–
1.11)
≥2
1.01 (0.42–
2.45)
1.01 (0.38–
2.63)
0.74 (0.32–
1.70)
1.01 (0.38–
2.70)
0.44 (0.18–
1.06)
0.41 (0.16–
1.06)
1.08 (0.44–
2.66)
1.40 (0.50–
3.91)
Pre-pregnancy BMI
Normal weight
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
Overweight
1.73 (1.09–
2.74)
1.79 (1.11–
2.89)
1.18 (0.77–
1.79)
0.85 (0.51–
1.50)
1.02 (0.65–
1.61)
1.08 (0.67–
1.75)
1.07 (0.68–
1.66)
1.21 (0.73–
2.00)
Obesity
1.04 (0.59–
1.99)
1.01 (0.52–
1.98)
2.03 (1.03–
3.98)
2.97 (1.28–
6.89)
0.71 (0.37–
1.36)
0.57 (0.28–
1.13)
1.76 (0.86–
3.60)
2.69 (1.23–
3.60)
Previous compliance with PA
No
1 (ref.)
1 (ref)
1 (ref.)
1 (ref.)
1 (ref)
1 (ref.)
Yes
4.82 (3.34–
6.94)
13.5 (8.12–
22.5)
2.02 (1.41–
2.89)
2.61 (1.72–
3.96)
1.82 (1.23–
2.69)
2.59 (1.65–
4.05)
Smoker
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Yes
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.)
1 (ref.) (
No
1.47 (0.99–
2.18)
1.56 (1.03–
2.37)
0.89 (0.52–
1.51)
0.67 (0.34–
1.32)
1.13 (0.63–
2.02)
1.08 (0.57–
2.03)
1.33 (0.73–
2.39)
0.99 (0.50–
1.97)
AMD
1.11 (1.00–
1.22)
1.11 (1.00–
1.24)
0.98 (0.89–
1.08)
0.95 (0.84–
1.07)
1.15 (1.03–
1.28)
1.17 (1.04–
1.33)
1.25 (1.12–
1.40)
1.16 (1.02–
1.31)
Abbreviations: AMD, adherence to Mediterranean diet; aOR, adjusted odds ratio; BMI, body mass index; CI, confidence
interval; cOR, crude odds ratio; PA, physical activity; T1, first trimester; T2, second trimester; T3, third trimester.
a aOR is adjusted for age, pre-pregnancy BMI, level of education, number of previous living children, previous ACOG compliance, and AMD.
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Figure 1. Flow chart of the cohort of pregnant women.
First interview (T1) (n=518)
Excluded (miscarriage) (n=32)
Met inclusion criteria (n=486)
Losses (n=50)
- Impossible to contact (n=47)
- Refused to participate (n=3)
Second interview (T2) (n=436)
Third interview (T3) (n=429)
Losses (n=33)
- Impossible to contact (n=19)
- Preterm delivery (n=12)
- Stillbirth (>24 GW) (n=2)
Inclusion (n=26)
- Women without second
interview are included in T3
Follow-up T2 and/or T3 (n=463)