Physical activity before and during pregnancy and risk of abnormal glucose tolerance among Hispanic women

Physical activity during pregnancy and the risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis

BACKGROUND

Previous research has indicated the inverse association between physical activity (PA) and gestational diabetes mellitus (GDM). However, the dose-response relationship currently remains undetermined. This study aims to explore the dose-response relationship between PA during the first and second trimesters of pregnancy and GDM risk.

METHODS

Studies on the relationship between PA during pregnancy and GDM risk published before April 25, 2023, were searched for in six databases. According to the inclusion and exclusion criteria, all literature was screened for eligibility. The Newcastle-Ottawa Scale (NOS) was used to assess risk of bias. Publication bias was examined using funnel plots, Begg's and Egger's tests, as well as trim-and-fill analysis. We harmonized exposure estimates of PA during pregnancy to the common unit of the metabolic equivalent of task (MET)-h/week. Restricted cubic splines were used to model the dose-response relationship. The criteria from the World Cancer Research Fund were used to assess the certainty of evidence across outcomes. All analyses were performed using Stata 15.1.

RESULTS

The results indicated that in contrast with the lowest level of PA, promoting the highest PA level lowers the risk of GDM by 36% (RR = 0.64, 95%CI: 0.53 ~ 0.78). We found a curvilinear dose-response association between PA during the first trimester and incident GDM (Pnonlinearity = 0.012). Compared to inactive pregnant women, for those who achieved the guidelines-suggested minimum level (10 MET-h/week) of PA during the first trimester, the GDM risk was decreased by 13% (RR = 0.87, 95%CI: 0.79 ~ 0.96). A linear relationship was found between PA during the second trimester and the GDM risk (Pnonlinearity = 0.276). The results with a restricted cubic spline model suggested that pregnant women who accumulate 10 MET-h/week have a 1% reduced risk of GDM compared to completely inactive individuals. Twice (20 MET-h/week) or a higher amount of PA (50 MET-h/week) contributed to further reductions in GDM risk.

CONCLUSION

There is a dose-response relationship between higher levels of PA in both the first and second trimesters and reduced risk of GDM; the relationship is stronger in the first trimester. Increasing PA during pregnancy can prevent the development of GDM.

PROSPERO REGISTRATION NUMBER

CRD42023420564.

Effects of Sedentary Behavior on the Complications Experienced by Pregnant Women: A Systematic Review

Pregnant women are encouraged to reduce sitting time and replace it with physical activity. Complications arising during pregnancy include gestational hypertension, preeclampsia, gestational diabetes mellitus (GDM), and prenatal and postpartum depression. In this systematic review, we examined effects of sedentary behavior on the health of pregnant women. We conducted a systematic review with PubMed from year 2000 to identify the relationship between a sedentary lifestyle and psychological effects, occurrence of GDM, gestational hypertension, and preeclampsia. Data extracted included sedentary time of pregnant women, psychological effects, occurrence of GDM, gestational hypertension, and preeclampsia as outcomes. Among the 200 studies retrieved, 11 were finally included after screening. The mean age of eligible pregnant women ranged from 28.5 to 32.9 years. Five studies were extracted with outcomes of psychological effects on the mother, five with GDM, and one with gestational hypertension/preeclampsia. Longer sedentary time was associated with increased risks of prepartum/postpartum depression in three of five studies and GDM in three of five studies. No association was found between sedentary behavior and the risk for gestational hypertension/preeclampsia. Higher sedentary behavior in the second trimester of pregnancy was likely to be associated with postpartum depression. Longer sitting time may increase the risk of prenatal or postnatal depression and GDM, but no relationship was proven for gestational hypertension and preeclampsia in one study. High sedentary behavior in the second trimester may have psychological impacts. The number of studies was small and further research is needed to statistically evaluate impacts of sedentary behavior during pregnancy.

Using social cognitive theory to explain physical activity in Iranian women preparing for pregnancy

Despite the known useful effects of regular physical activity during the preconception period on pregnancy outcomes, sedentary lifestyle is a prevalent phenomenon in reproductive-aged women. Using social cognitive theory (SCT) as its theoretical framework, the aim of this study was to explain physical activity model in the women preparing for pregnancy in Isfahan, Iran. This cross-sectional study was conducted on 220 Iranian women undergoing preconception care. The SCT constructs were measured using a researcher-made questionnaire. The duration of physical activity with moderate/severe intensity was also measured using the long form of the International Physical Activity Questionnaire. The data were analyzed using Spearman correlation coefficient and multivariable linear regression. The theoretical model was tested using structural equation modeling. The results showed that observational learning (β =.65, p <.0001) was the most important determinant of the physical activity level. The default model provided an adequate to good fit to the data (CMIN/DF = 2.10, p =.097). The results of the present study emphasized the role of observational learning in forming physical activity behavior in pre-pregnancy period; therefore, the design of interventions for providing the opportunity of observational learning may improve the level of physical activity among the women preparing for pregnancy.

Validity of self-reported and objectively measured sedentary behavior in pregnancy

Background

Sedentary behavior (SED) is a potential risk factor for poor pregnancy outcomes. We evaluated the validity of several common and one new method to assess SED across three trimesters of pregnancy.

Methods

This cohort study of pregnant women measured objective and self-reported SED each trimester via thigh-worn activPAL3 micro (criterion), waist-worn Actigraph GT3X, and self-report from the Pregnancy Physical Activity Questionnaire (PPAQ) and the de novo Sedentary Behavior Two Domain Questionnaire (SB2D). SED (hours per day) and percent time in SED (SED%) from activPAL were compared to GT3X, SB2D, and PPAQ using Pearson’s r, ICC, Bland-Altman analysis, and comparison of criterion SED and SED% across tertiles of alternative methods.

Results

Fifty-eight women (mean age 31.5 ± 4.8 years; pre-pregnancy BMI 25.1 ± 5.6 kg/m²; 76% white) provided three trimesters of valid activPAL data. Compared to activPAL, GT3X had agreement ranging from r = 0.54–0.66 and ICC = 0.52–0.65. Bland-Altman plots revealed small mean differences and unpatterned errors, but wide limits of agreement (greater than ±2 h and ± 15%). The SB2D and PPAQ had r < 0.5 and ICC < 0.3 vs. activPAL SED, with lower agreement during the 2nd and 3rd trimesters, and performed poorly in Bland-Altman analyses. SED% from the modified SB2D performed best of the self-reported instruments with modest mean differences, r ranging from 0.55 to 0.60, and ICCs from 0.31–0.33; though, limits of agreement were greater than ±35%. Significant trends in activPAL SED were observed across increasing tertiles of SB2D SED in the 1st and 3rd trimesters (both p ≤ 0.001), but not the 2nd trimester (p = 0.425); and for PPAQ SED in the 1st and 2nd trimesters (both p < 0.05), but not the 3rd trimester (p = 0.158). AcitvPAL SED and SED% increased significantly across tertiles of GT3X SED and SED% as well as SB2D SED% (all p-for-trend ≤ 0.001).

Conclusions

Compared to activPAL, waist-worn GT3X produced moderate agreement, though similar mean estimates of SED across pregnancy. Self-report questionnaires had large absolute error and wide limits of agreement for SED hr./day; SB2D measurement of SED% was the best self-report method. These data suggest activPAL be used to measure SED when possible, followed by GT3X, and – when necessary – SB2D assessing SED% in pregnancy.

Trial registration

www.clinicaltrials.govNCT03084302 on 3/20/2017.

Physical activity pattern in early pregnancy and gestational diabetes mellitus risk among low-income women: A prospective cross-sectional study

Objective:

Gestational diabetes mellitus is increasing worldwide, mainly in developing countries, and physical activity has not been studied in gestational diabetes mellitus prevention among low-income population. This prospective cross-sectional study assessed the gestational diabetes mellitus risk related to physical activity in early pregnancy among low-income women.

Methods:

A prospective cross-sectional study with 544 low-income pregnant women was conducted at the Instituto de Medicina Integral Prof. Fernando Figueira, Brazil. Gestational diabetes mellitus was diagnosed using the International Association of Diabetes and Pregnancy Study Groups criteria. Physical activity was assessed during early pregnancy using the Pregnancy Physical Activity Questionnaire and categorized as sedentary, light, moderate, or vigorous intensity.

Results:

Gestational diabetes mellitus occurred in 95 of 544 women (17.4%). Body mass index was higher in the gestational diabetes mellitus group. Nearly half of all pregnant women studied were physically inactive, and none of them were classified as vigorous physical active. Sedentary physical activity pattern was associated with a higher odds of gestational diabetes mellitus (odds ratio = 1.8, 95% confidence interval = 1.1–2.9), which did not change after adjusting for several covariates (odds ratio = 1.9, 95% confidence interval = 1.2–3.1).

Conclusion:

Physical inactivity in early pregnancy is associated with a higher risk of gestational diabetes mellitus among low-income women.

Higher Numbers of Pregnancies Associated With an Increased Prevalence of Gestational Diabetes Mellitus: Results From the Healthy Baby Cohort Study

Background

Pregnancy leads to substantial maternal metabolic and lifestyle alterations. However, it is still unclear whether repeated exposure to these changes will influence the development of gestational diabetes mellitus (GDM). In the present study, we aimed to investigate the association between the number of pregnancies and GDM among Chinese women.

Methods

A total of 7,008 subjects from the Healthy Baby Cohort study were included in this study. The number of pregnancies was classified into three categories: 1, 2, or ≥3 pregnancies. GDM was diagnosed using International Association of Diabetes and Pregnancy Study Groups criteria. Multivariate logistic regression models were used.

Results

In the fully adjusted model, women with ≥3 pregnancies had a 1.27-fold (95% confidence interval [CI], 1.05–1.54) higher risk of GDM. Among women ≥30 years old, 2 and ≥3 pregnancies were associated with a higher risk of GDM (odds ratio [OR] 1.32; 95% CI, 1.01–1.73 and OR 1.54; 95% CI, 1.17–2.01, respectively). Among women with a pre-pregnancy BMI <24 kg/m², ≥3 pregnancies were associated with a 1.35-fold (95% CI, 1.09–1.67) higher risk of GDM.

Conclusions

Our findings suggested that higher numbers of pregnancies is an independent risk factor of GDM. The association between number of pregnancies and GDM was more prominent among women who were ≥30 years old or with a pre-pregnancy BMI <24 kg/m².

Physical activity for healthy pregnancy among Iranian women: Perception of facilities versus perceived barriers

BACKGROUND

Regular physical activity during preconception period has beneficial effects on the health of women during conception and the identification of factors associated with it is an effective factor for improving the behavior. Therefore, the aim of this study is to evaluate the relationship between the physical activity and health belief model (HBM) constructs (perceived susceptibility/severity, barriers, and self-efficacy) as intrapersonal factors among women undergoing preconception care.

METHODS

In this cross-sectional study, 110 women who were undergoing preconception care were carried out. Moreover, health belief constructs and attitude toward physical activity were assessed through the use of researcher-made questionnaire. In addition, the duration of physical activity with moderate/vigorous intensity was evaluated utilizing a long form of the International Physical Activity Questionnaire.

RESULTS

The results showed that although there was a relationship between the all health belief constructs and attitude toward physical activity and the duration of leisure physical activities carried out during (P < 0.05), but using the linear regression test showed that only perceived barriers, independent from other variables, had a significant inverse correlation with this type of activities (β = -0.27, P = 0.02).

CONCLUSION

The findings of this study showed that among the constructs of theHBM, perceived barriers are the most important predictor of physical activity in women during the preconception period and emphasize the need to design possible means to promote physical activity to remove barriers to effective physical activity.

Physical activity during pregnancy is associated with a lower prevalence of gestational diabetes mellitus in Vietnam

AIMS

To assess the association between physical activity (PA) during pregnancy and the prevalence of gestational diabetes mellitus (GDM) accounting for sitting time.

METHODS

The study used data from a cohort study of 2030 pregnant women in Vietnam. Women were recruited from six hospitals in Ha Noi, Hai Phong, and Ho Chi Minh City. Baseline measurements including PA and GDM were taken at 24-28 weeks of gestation. PA was assessed during the past 3 months before the interview using the interviewer-administered Pregnancy Physical Activity Questionnaire. GDM was diagnosed at 24-28 weeks of gestation using the 2013 World Health Organization criteria.

RESULTS

1987 out of 2030 pregnant women were included in the final analysis, of which 432 had GDM (21.7%). Women undertaking the highest level (upper tertile) of PA during pregnancy appeared to have a lower risk of GDM [odds ratio (OR) 0.70, 95% confidence interval (CI) 0.53-0.94, P_trend 0.017] when compared to those at the lowest tertile of PA. Similarly, women with increased levels of moderate-intensive activity and household/caregiving activity during pregnancy were associated with reduced risks of GDM (OR 0.66, 95% CI 0.50-0.86, P_trend 0.002 and OR 0.72, 95% CI 0.55-0.95, P_trend 0.020, respectively). These apparent inverse associations were not attenuated by their sitting time. There were no significant associations between sitting time, light-intensity activity, vigorous-intensity activity, occupation, sports/exercise, commuting, or meeting exercise guidelines and GDM risk.

CONCLUSIONS

High levels of PA, particularly moderate-intensity and household/caregiving activities during pregnancy were associated with a lower prevalence of GDM independent of sitting time.

Effect of Physical Activity during Pregnancy on Gestational Diabetes Mellitus

AIMS

The present study evaluates association between physical activity and Gestational Diabetes Mellitus (GDM), for it can be an effective intervention for its management. Though physical activity helps maintain glucose homeostasis, evidences of GDM risk are less extensive. Therefore, this study also identifies its correlation with maternal blood glucose levels.

MATERIALS AND METHODS

A prospective case-control study was carried out among pregnant women attending regular antenatal clinic at two private hospitals. The study comprised of 100 cases and 273 matched controls. Data was collected by personal interviews using a standard questionnaire. Physical activity was assessed using long form of International Physical Activity Questionnaire (IPAQ) reported as Metabolic Equivalent-Minutes per week (MET-Minutes/Week). Statistical Package for Social Sciences (SPSS) was used for analysis.

RESULTS

Results shows high exposure rates for low-to-moderate physical activity among cases, across all domains and sub-activities. The odds of GDM engaged in domestic and gardening activities for <2999 MET-minutes per week are 10 times higher than involved for ≥3000 MET-minutes per week (P < 0.001). The study also shows poor or no correlation between physical activity during pregnancy and maternal blood glucose levels.

CONCLUSION

Despite existence of poor or no relationship with maternal blood glucose levels, prolonged sedentary behavior and decreased physical activities, especially domestic, are potential risk factors for GDM, a major finding of the study.

Associations of Diet and Physical Activity with Risk for Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

Rising rates of gestational diabetes mellitus (GDM) and related complications have prompted calls to identify potentially modifiable risk factors that are associated with gestational diabetes mellitus (GDM). We systematically reviewed the scientific literature for observational studies examining specific dietary and/or physical activity (PA) factors and risk of GDM. Our search included PubMed, Medline, CINAHL/EBSCO, Science Direct and EMBASE, and identified 1167 articles, of which 40 met our inclusion criteria (e.g., singleton pregnancy, reported diet or PA data during pre-pregnancy/early pregnancy and GDM as an outcome measure). Studies were assessed for quality using a modified Quality Criteria Checklist from American Dietetic Association. Of the final 40 studies, 72% obtained a positive quality rating and 28% were rated neutral. The final analysis incorporated data on 30,871 pregnant women. Dietary studies were categorised into either caffeine, carbohydrate, fat, protein, calcium, fast food and recognized dietary patterns. Diets such as Mediterranean Diet (MedDiet), Dietary Approaches to Stop Hypertension (DASH) diet and Alternate Healthy Eating Index diet (AHEI) were associated with 15–38% reduced relative risk of GDM. In contrast, frequent consumption of potato, meat/processed meats, and protein (% energy) derived from animal sources was associated with an increased risk of GDM. Compared to no PA, any pre-pregnancy or early pregnancy PA was associated with 30% and 21% reduced odds of GDM, respectively. Engaging in >90 min/week of leisure time PA before pregnancy was associated with 46% decreased odds of GDM. We conclude that diets resembling MedDiet/DASH diet as well as higher PA levels before or in early pregnancy were associated with lower risks or odds of GDM respectively. The systematic review was registered at PROSPERO (www.crd.york.ac.uk/PROSPERO) as CRD42016027795.

Seremban Cohort Study (SECOST): a prospective study of determinants and pregnancy outcomes of maternal glycaemia in Malaysia

INTRODUCTION

Both gestational diabetes mellitus (GDM) and hyperglycaemia less severe than GDM are associated with risk of adverse pregnancy outcomes. We describe the study design of a prospective cohort of pregnant women recruited in early pregnancy with follow-ups of mothers and infants up to 2 years after birth. The primary aim of the study was to identify the determinants and outcomes of maternal glycaemia.

METHODS AND ANALYSIS

Seremban Cohort Study (SECOST) is an ongoing prospective cohort study in which eligible pregnant women in first trimester (<10 weeks of gestation) are recruited from Maternal and Child Health clinics in Seremban District, Negeri Sembilan with seven follow-ups during pregnancy through 2 years postnatally. Infants are followed up every 6 months after birth until 2 years old. A standard 75 g oral glucose tolerance test is performed between 24 and 32 of weeks of gestation and as close to 28 weeks of gestation. Pregnancy and birth information are obtained from medical records. Sociodemographic, anthropometric, biochemical, dietary, physical activity, smoking, depression, child feeding and other data of mothers and infants are obtained at follow-ups.

ETHICS AND DISSEMINATION

This study is approved by the Medical Research Ethics Committee (MREC), Universiti Putra Malaysia (UPM/FPSK/100-9/2-MJKEtika) and MREC, Ministry of Health Malaysia (KKM/NIHSEC/08/0804/P12- 613). Permission to conduct this study is also obtained from the Head of Seremban District Health Office. All participants are required to provide written informed consent prior to data collection. The research findings will be disseminated at journals and conference presentations.

The Health Behaviors of Ethnically Diverse Women at Increased Risk of Gestational Diabetes: The Behaviors Affecting Baby and You (B.A.B.Y.) Study

Objectives Cigarette smoking, low physical activity, and sedentary behavior are modifiable risk factors for adverse pregnancy outcomes. However, only one study has evaluated predictors of these health risk behaviors among women at high risk for gestational diabetes mellitus (GDM). Therefore, our goal was to examine predictors of smoking, low physical activity, and sedentary behavior during pregnancy in an ethnically diverse high risk cohort. Methods This cross-sectional analysis utilized baseline data from the Behaviors Affecting Baby and You (B.A.B.Y.) study conducted among prenatal care patients at high risk for GDM (personal history of GDM or family history of diabetes and body mass index [BMI] ≥ 25 kg/m²). Smoking was assessed using questions from the Pregnancy Risk Assessment Monitoring System questionnaire and sedentary behavior (top vs. lower quartiles) and moderate/vigorous physical activity (bottom vs. upper quartile) via the Pregnancy Physical Activity Questionnaire. Results Participants (n = 400) enrolled at a mean of 12.4 (SD 3.6) weeks gestation. A total of 150 (44.1%) engaged in one, 37 (10.9%) in two, and 4 (1.2%) in three risk behaviors. Lower household income and not having children at home were each associated with a 2-6 fold increased odds of smoking, high sedentary behavior, and engaging in at least one risk behavior. Being married, Hispanic or of younger age was associated with a 2-6 fold reduced odds of smoking. BMI and personal history of GDM were not associated with risk behaviors. Conclusions for Practice Findings help characterize high risk groups and inform prenatal interventions targeting these health risk behaviors.

Patient-Provider Communication and Counseling about Gestational Weight Gain and Physical Activity: A Qualitative Study of the Perceptions and Experiences of Latinas Pregnant with their First Child

Latina women in the United States (U.S.) are disproportionately affected by obesity and are more likely to begin pregnancy overweight and gain excessive weight during pregnancy. The prenatal care period represents a window of opportunity for women to access the healthcare system and receive preventive services, education, nutritional support, and other social services to improve pregnancy outcomes. Excessive gestational weight gain (GWG) has numerous negative short- and long-term consequences for both the mother and newborn. We explored nulliparous Latina women's perceptions about their experiences communicating with their primary healthcare provider about GWG and physical activity (PA) to identify possible intervention targets using in-depth, semi-structured interviews. Bilingual, trained research staff conducted 23 interviews with first-time pregnant Latinas between 22 and 36 weeks of gestation. Interviews were transcribed verbatim and analyzed using content analysis. Salient text passages were extracted, shortened, coded, and grouped into categories. Women, including those who self-identified as being overweight or obese prior to pregnancy, reported receiving limited or no advice from their healthcare providers about GWG or PA. Additionally, analysis revealed that although participants value information received from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) program counselors, they would like to receive more information from their primary healthcare providers about adequate GWG. Furthermore, study findings indicate that some participants received conflicting information regarding PA during pregnancy. Study findings suggest the need for increased integration of communication and counseling about GWG and PA into prenatal care services to promote healthy weight gain and PA among low-income Latina women.

Associations of physical activity and sedentary behavior during pregnancy with gestational diabetes mellitus among Asian women in Singapore

BACKGROUND

Few studies have investigated physical activity (PA) and sedentary behavior (SB) in relation to fasting (FG) and 2-h postprandial plasma glucose (2hPG) levels and gestational diabetes mellitus (GDM); we investigated these associations among Asian pregnant women.

METHODS

As part of the Growing Up in Singapore Towards healthy Outcomes cohort study, PA and SB (sitting and television times) were assessed by interviewer-administered questionnaire. During 75 g oral glucose tolerance tests at 26-28 weeks' gestation we measured FG, 2hPG levels and GDM (FG ≥ 7.0 mmol/L and/or 2hPG ≥ 7.8 mmol/L). Associations were analysed by multiple linear and logistic regression.

RESULTS

Among the 1083 women studied, 18.6% had GDM. SB was not associated with FG, 2hPG and GDM. Higher categories of PA were associated with lower 2hPG and a lower likelihood of GDM (p-trend < 0.05), but not with FG levels. Compared to insufficiently active women, highly active women had lower 2hPG levels [β (95% CI): -0.32 (-0.59, -0.05), p = 0.020) and were less likely to have GDM [OR: 0.56 (0.32-0.98), p = 0.040]. Stratified analysis revealed no associations among under/normal-weight women, but significant associations among overweight/obese women; in those with BMI ≥23 kg/m2, sufficiently active and highly active women were less likely to have GDM [OR: 0.52, (0.29-0.93), p = 0.028, and OR: 0.34, (0.15-0.77), p = 0.010, respectively].

CONCLUSION

Higher PA was associated with lower 2hPG levels and a lower prevalence of GDM, particularly in overweight/obese women. Further studies are warranted to confirm these findings, and to examine the effectiveness of PA promotion strategies for the prevention of gestational hyperglycemia.

Physical activity and the risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis of epidemiological studies

Physical activity has been inconsistently associated with risk of gestational diabetes mellitus in epidemiological studies, and questions remain about the strength and shape of the dose-response relationship between the two. We therefore conducted a systematic review and meta-analysis of cohort studies and randomized trials on physical activity and gestational diabetes mellitus. PubMed, Embase and Ovid databases were searched for cohort studies, and randomized controlled trials of physical activity and risk of gestational diabetes mellitus, up to August 5th 2015. Summary relative risks (RRs) were estimated using a random effects model. Twenty-five studies (26 publications) were included. For total physical activity the summary RR for high versus low activity was 0.62 (95 % CI 0.41-0.94, I2 = 0 %, n = 4) before pregnancy, and 0.66 (95 % CI 0.36-1.21, I2 = 0 %, n = 3) during pregnancy. For leisure-time physical activity the respective summary RRs for high versus low activity was 0.78 (95 % CI 0.61-1.00, I2 = 47 %, n = 8) before pregnancy, and it was 0.80 (95 % CI 0.64-1.00, I2 = 17 %, n = 17) during pregnancy. The summary RR for pre-pregnancy activity was 0.70 (95 % CI 0.49-1.01, I2 = 72.6 %, n = 3) per increment of 5 h/week and for activity during pregnancy was 0.98 (95 % CI 0.87-1.09, I2 = 0 %, n = 3) per 5 h/week. There was evidence of a nonlinear association between physical activity before pregnancy and the risk of gestational diabetes mellitus, pnonlinearity = 0.005, with a slightly steeper association at lower levels of activity although further reductions in risk were observed up to 10 h/week. There was also evidence of nonlinearity for physical activity in early pregnancy, pnonlinearity = 0.008, with no further reduction in risk above 8 h/week. There was some indication of inverse associations between walking (before and during pregnancy) and vigorous activity (before pregnancy) and the risk of gestational diabetes mellitus. This meta-analysis suggests that there is a significant inverse association between physical activity before pregnancy and in early pregnancy and the risk of gestational diabetes mellitus. Further studies are needed to clarify the association between specific types and intensities of activity and gestational diabetes mellitus.

Effects of Online Self-Regulation Activities on Physical Activity Among Pregnant and Early Postpartum Women

Physical and psychological changes that occur during pregnancy present a unique challenge for women's physical activity. Using a theory-based prospective design, this study examines the effects of pregnant women's (a) physical activity cognitions (self-efficacy, outcome expectancy, and safety beliefs) and (b) online self-regulation activities (goal-setting and self-monitoring) on subsequent changes in their physical activity intentions and behavior during pregnancy and immediately postpartum. The authors used data from three panel surveys administered to pregnant women enrolled in a web-based intervention to promote healthy pregnancy and postpartum weight, as well as log data on their use of self-regulatory features on the intervention website. Perceived self-efficacy and perceived safety of physical activity in pregnancy enhanced subsequent intentions to be physically active. Repeated goal-setting and monitoring of those goals helped to maintain positive intentions during pregnancy, but only repeated self-monitoring transferred positive intentions into actual behavior. Theoretically, this study offers a better understanding of the roles of self-regulation activities in the processes of goal-striving. The authors also discuss practical implications for encouraging physical activity among pregnant and early postpartum women.

The first trimester: prediction and prevention of the great obstetrical syndromes

A number of groups are currently examining the potential of screening for pre-eclampsia and gestational diabetes at 12 weeks' gestation. This can be performed at the time of combined first-trimester screening for aneuploidy using a similar method of regression analysis to combine multiple demographic and investigative factors. At present, research into the prediction of pre-eclampsia is more robust and is associated with the potential for therapeutic intervention that can reduce the prevalence of early-onset pre-eclampsia and improve maternal and neonatal outcomes.