Maternal and Perinatal Outcomes of Exercise in Pregnant Women with Chronic Hypertension and/or Previous Preeclampsia: A Randomized Controlled Trial

The association of physical activity during pregnancy with birthweight extremes: A scoping review

OBJECTIVES

Birthweight (BW) indicates newborn health and is a risk factor for development of chronic diseases later in life. The aim was to investigate whether or not prenatal physical activity (PA) influences BW extremes and how PA influences BW extremes in those diagnosed with pregnancy-related diseases.

DESIGN

We performed a scoping review.

METHODS

Searches were completed on five databases and studies identified were uploaded to Covidence.

RESULTS

Across the five databases 3114 studies were identified and after screening, 69 of these studies were used for the final review. Of the 61 studies that considered low BW (LBW)/small for gestational age (SGA) infants, the majority of results (69 %) indicated that PA during pregnancy had no significant impact on LBW or SGA infants. In addition, 11 % of studies reported a significant decrease in the prevalence of LBW infants, however two studies (3 %) reported a significant increase in LBW or SGA infants, likely relating to individuals with high body mass index and poor adherence to PA. Of the 41 studies that did report LGA/macrosomia, 34 % reported that PA significantly reduced the prevalence of higher BW infants. One study reported the association between meeting exercise recommendations and reducing the odds of LGA infants in those with pregnancy-related diseases.

CONCLUSIONS

We provide evidence on the association of prenatal PA with BW extremes. It is suggested that prenatal PA does not increase the risk of delivering LBW/SGA infants and may reduce the prevalence of large BW infants. Further research is needed to confirm these relationships and explain their underlying mechanisms.

Effect of daily physical activity on ambulatory blood pressure in pregnant women with chronic hypertension: A prospective cohort study protocol

BACKGROUND

Physical activity, a first-line approach for the treatment of non-gestational hypertension globally, has been shown to benefit most pregnant women in many respects. The benefits and risks of prenatal physical activity in complicated pregnancies, such as preeclampsia and chronic hypertension, require further investigation. It is worth conducting studies to address questions about physical activity during pregnancy in women with chronic hypertension, such as the benefits and risks, frequency, duration, and intensity. This prospective cohort study aims to investigate whether moderate-intensity daily physical activity reduces ambulatory blood pressure in pregnant women with chronic hypertension.

METHODS

Pregnant women with chronic hypertension at 11+0 to 13+6 gestational weeks will be recruited from the outpatient clinic and divided into moderate- and light-intensity physical activity groups according to the intensity of the 7-day physical activity monitored using the model wGT3X-BT accelerometer. 24-h ambulatory blood pressure monitoring will be performed at enrollment as a baseline and will be repeated in the second and third trimesters. The primary outcome is the difference in the change in 24-h ambulatory systolic blood pressure from the first to the third trimester between the groups. Secondary outcomes include the difference of change in other ambulatory (24-h diastolic, daytime, and nighttime) and office blood pressure variables from the first to the second and third trimesters, the incidence of severe hypertension (≥160/110 mmHg), and changes in the type and dosage of antihypertensive medication. The primary and secondary outcomes related to changes in blood pressure from baseline to the second and third trimesters between the groups will be analyzed using Student's independent t-test or the Mann-Whitney U test.

DISCUSSION

This cohort study will provide a basis for randomized controlled trials and verify an easily achieved, economical, and non-fetotoxic approach for adjuvant blood pressure management in pregnant women with chronic hypertension.

REGISTRY

This study is registered with the Chinese Clinical Trials Registry (NO. ChiCTR2200062094). Date Registered: 21/07/2022.

Exercise during pregnancy for preventing gestational diabetes mellitus and hypertensive disorders: An umbrella review of randomised controlled trials and an updated meta-analysis

OBJECTIVE

This study aimed to provide, through an umbrella review, an overview of the effect of single exercise interventions during pregnancy on gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP). Also, to update the current evidence through an updated meta-analysis.

DESIGN

Umbrella review.

SETTING

PubMed, EMBASE, Web of Science, Cochrane database of systematic reviews, Epistemonikos, SPORTDiscus, Clinicaltrials.gov, and PROSPERO register were searched from the database inception until August 2021.

POPULATION

Peer-reviewed systematic reviews and meta-analyses of randomised controlled trials (RCTs) and RCTs samples.

METHODS

Random-effects model was used to calculate relative risk with 95% confidence interval in the updated meta-analysis. The reference category was the groups that received usual prenatal care. AMSTAR 2 and the Cochrane Collaboration tool were used to assess the quality and GRADE approach was used to assess the overall certainly of evidence.

MAIN OUTCOME MEASURES

GDM and HDP relative risk.

RESULTS

Twenty-three systematic reviews and meta-analyses; and 63 RCTs were included. Single exercise interventions reduced the incidence of GDM and HDP in most systematic reviews and meta-analyses. Moreover, exercise interventions during pregnancy decrease the incidence of developing GDM and GH, particularly when they are supervised, have a low to moderate intensity level, and are initiated during the first trimester of pregnancy.

CONCLUSION

Based on the findings, obstetric and physical exercise professionals could recommend exercise interventions during pregnancy as an effective strategy to improve maternal outcomes.

Effects of Supervised Exercise on the Development of Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-Analysis

Hypertensive disorders of pregnancy (HDP) are the most common medical complication in pregnancy, affecting approximately 10-15% of pregnancies worldwide. HDP are a major cause of maternal and perinatal morbidity and mortality, and each year, worldwide, around 70,000 mothers and 500,000 babies die because of HDP. Up-to-date high-quality systematic reviews quantifying the role of exercise and the risks of developing HDP are currently lacking. Physical exercise is considered to be safe and beneficial to pregnant women. Supervised exercise has been shown to be safe and to be more beneficial than unsupervised exercise in the general population, as well as during pregnancy in women with obesity and diabetes. Therefore, we undertook a systematic review and meta-analysis to investigate the effects of women performing supervised exercise during pregnancy compared to a control group (standard antenatal care or unsupervised exercise) on the development of HDP. We searched Medline, Embase, CINHAL, and the Cochrane Library, which were searched from inception to December 2021. We included only randomized controlled trials (RCTs) investigating the development of HDP compared to a control group (standard antenatal care or unsupervised exercise) in pregnant women performing supervised exercise. Two independent reviewers selected eligible trials for meta-analysis. Data collection and analyses were performed by two independent reviewers. The PROSPERO registration number is CRD42020176814. Of 6332 articles retrieved, 16 RCTs met the eligibility criteria, comparing a total of 5939 pregnant women (2904 pregnant women in the intervention group and 3035 controls). The risk for pregnant women to develop HDP was significantly reduced in the intervention compared to the control groups, with an estimated pooled cumulative incidence of developing HDP of 3% in the intervention groups (95% CI: 3 to 4) and of 5% in the control groups (95% CI: 5 to 6), and a pooled odds ratio (OR) comparing intervention to control of 0.54 (95% CI:0.40 to 0.72, p < 0.001). A combination of aerobic and anaerobic exercise, or yoga alone, had a greater beneficial effect compared to performing aerobic exercise only (mixed-OR = 0.50, 95% CI:0.33 to 0.75, p = 0.001; yoga-OR = 0.28, 95% CI:0.13 to 0.58, p = 0.001); aerobic exercise only-OR = 0.87, 95% CI:0.55 to 1.37, p = 0.539). Pregnancy is an opportunity for healthcare providers to promote positive health activities, thus optimizing the health of pregnant women with potential short- and long-term benefits for both mother and child. This systematic review and meta-analysis support a beneficial effect of either structured exercise (combination of aerobic, strength, and flexibility workouts) or yoga for preventing the onset of HDP. Yoga, considered a low-impact physical activity, could be more acceptable and safer for women in pregnancy in reducing the risk of developing HDP.

Exercise versus Metformin to Improve Pregnancy Outcomes among Overweight Pregnant Women: A Systematic Review and Network Meta-Analysis

Being overweight is associated with pregnancy-related disorders such as gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), and excessive maternal weight gain (MWG). Exercise and metformin reduce the risk of these disorders. This network meta-analysis (NMA) aims to compare the effect of metformin and different types of exercise (aerobic, resistance and combined) on the risk of GDM, HDP, and MWG among overweight/obese pregnant women. Medline, EMBASE, Web of Science and Cochrane Library were searched from inception to June 2021. Meta-analyses and NMAs were performed. Sixteen randomized controlled trials were included. In the NMA, aerobic exercise showed an effect on GDM (RR = 0.51, 95% CI = 0.26, 0.97), and metformin a reduction in MWG (MWG = -2.93 kg, 95% CI = -4.98, -0.87). No intervention showed any effect on the reduction of HDP. Our study suggests that aerobic exercise may have the greatest effect in reducing the risk of GDM, and perhaps, the MWG. Strategies should be developed to increase adherence to this type of intervention among overweight women without contraindications. Although metformin could reduce MWG, medicalization of pregnancy in healthy women is not justified with the present results. More research is needed on the effect of the intensity and frequency of exercise sessions and the length of interventions.

The Effect of Exercise Training During Pregnancy to Improve Maternal Vascular Health: Focus on Gestational Hypertensive Disorders

Hypertensive disorders of pregnancy, including gestational hypertension and pre-eclampsia, occur in up to 10% of pregnancies and are associated with increased life-long cardiovascular risk. Physical activity improves cardiovascular health in pregnancy and may lower the risk of developing hypertensive disorders of pregnancy. However, a minority of pregnant women comply with the recommended level of physical activity. Adequate knowledge on the physiological effects of exercise in healthy pregnancy could help to overcome potential barriers as pregnancy is a unique window of opportunity to improve health outcomes for both mother and child. In this mini review, we discuss structural and functional vascular adaptations during healthy and hypertensive pregnancies, we elaborate on the effects of exercise on the vasculature and review the safety and existing evidence of exercise training as preventive therapy for gestational hypertensive disorders.

Physical exercise and metformin in the prevention of pre-eclampsia: systematic review

Abstract Introduction: Pre-eclampsia is a disorder that may occur during pregnancy but is still unknown and / or multifactorial causes. Objective: To verify whether physical exercise and metformin may be helpful in preventing preeclampsia. Method: This is a systematic review of the literature in PubMed / MEDLINE, Web of Science, Scopus, LILACS and Cochrane. This review followed the critiques of the PRISMA checklist. Bias assessment was used for the Cochrane Handbook for Systematical Reviews of Interventions (Version 5.1.0) for clinical trials and the Downs and Black scale for cohort and case-control studies. Results: 17 studies were within the established criteria. The subjects evaluated were: pre-eclampsia, cardiovascular metabolic factors, physiotherapeutic therapies and the effects of physical exercise and metformin on the circulatory system. Conclusion: There is a need for adapted techniques and new protocols according to the contingencies and complications of pregnancy. During pregnancy, it is suggested a greater interdisciplinarity of knowledge among professionals and that the therapy receives adjustments against the metabolic alterations of the reproductive system. In order to prevent preeclampsia, the study suggests a program of individual exercises that include greater assistance, verification and / or comprehension of possible changes and their limits during pregnancy. As well as, the adjuvant use of metformin of 1000 mg/d in the initial phase, with the purpose of maintaining the effects of the drug due to renal clearance during pregnancy, until reaching a maximum of 1500 mg/d, to avoid side effects of the drug.

The effect of walking on pregnancy blood pressure disorders in women susceptible to pregnancy hypertension: A randomized clinical trial

BACKGROUND AND OBJECTIVES

Hypertension in pregnancy is one of the most important unsolved problems in midwifery, and since it is the main cause of maternal death, preventive intervention measures are essential to control this serious complication. This study aimed to determine the effect of walking on gestational hypertension disorders in women prone to hypertension.

MATERIALS AND METHODS

This randomized clinical trial was conducted on 72 pregnant women susceptible to gestational hypertension who were randomly (through a random number table) assigned into two groups of 36. The pregnant women in the experimental group had walking program for 20-30 min from weeks 14-34, four times a week. Data were analyzed, via independent t-test, Fisher's exact test, and Chi-square test.

RESULTS

The results indicated that in the experimental group, 2 cases with transient gestational hypertension and 1 case of preeclampsia existed, and in the control group, 9 pregnant women were with gestational hypertension and 4 pregnant women were with preeclampsia. Therefore, the incidence of these two complications in the experimental group was significantly lower than the control group (P < 0.05). Moreover, the mean systolic and diastolic blood pressures in the experimental group were significantly lower than the control group (P < 0.05).

CONCLUSION

Based on the results, the moderate walking, as an easy physical activity, is recommended for pregnant women susceptible to pregnancy hypertension.

Effect of Self-care Before and During Pregnancy to Prevention and Control Preeclampsia in High-risk Women

Our aims to examine the factors influencing self-care for the prevention and control of preeclampsia in high-risk women. The current study is a review where the researcher browsed the available databases such as PubMed, Cochrane, Medline, Google Scholar, Medscape, and relevant research published between 1980 and 2016 were studied. To search for articles, relevant Medical Subject Heading keywords were first determined (Self-care, preeclampsia, prevention.) A total of 350 related articles were first selected, and the findings of 70 were used to compile the present article. The results of the study were classified under two general categories, including (1). Counseling and screening strategies and (2) self-care strategies for the prevention and control of preeclampsia in high-risk women. Screening women at risk for preeclampsia include measures such as measuring their blood pressure, checking for signs of depression, testing for thrombosis, taking a history of preeclampsia, providing preconception counseling about the appropriate age, time of pregnancy, and encouraging weight loss in obese women. This review showed a positive relationship between knowledge about self-care for preeclampsia and its control. The factors influencing preeclampsia self-care include making lifestyle changes, having a healthy diet, learning stress management, performing exercise and physical activities, taking antioxidants, dietary supplements, and calcium and adherence to aspirin and heparin regimens. There is a positive relationship between preconception counseling, screening women at risk for preeclampsia, self-care for the prevention, and control of preeclampsia.

(1) Tweetable abstract self-care in high-risk women is strongly associated with prevention and control of preeclampsia.

Impact of prenatal exercise on maternal harms, labour and delivery outcomes: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review of the relationships between prenatal exercise and maternal harms including labour/delivery outcomes.

DESIGN

Systematic review with random effects meta-analysis and meta-regression.

DATASOURCES

Online databases were searched up to 6 January 2017.

STUDY ELIGIBILITY CRITERIA

Studies of all designs were included (except case studies) if they were published in English, Spanish or French and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise, alone ["exercise-only"] or in combination with other intervention components [e.g., dietary; "exercise + co-intervention"]) and outcome (preterm/prelabour rupture of membranes, caesarean section, instrumental delivery, induction of labour, length of labour, vaginal tears, fatigue, injury, musculoskeletal trauma, maternal harms (author defined) and diastasis recti).

RESULTS

113 studies (n=52 858 women) were included. 'Moderate' quality evidence from exercise-only randomised controlled trials (RCTs) indicated a 24% reduction in the odds of instrumental delivery in women who exercised compared with women who did not (20 RCTs, n=3819; OR 0.76, 95% CI 0.63 to 0.92, I ²= 0 %). The remaining outcomes were not associated with exercise. Results from meta-regression did not identify a dose-response relationship between frequency, intensity, duration or volume of exercise and labour and delivery outcomes.

SUMMARY/CONCLUSIONS

Prenatal exercise reduced the odds of instrumental delivery in the general obstetrical population. There was no relationship between prenatal exercise and preterm/prelabour rupture of membranes, caesarean section, induction of labour, length of labour, vaginal tears, fatigue, injury, musculoskeletal trauma, maternal harms and diastasis recti.

Impact of prenatal exercise on neonatal and childhood outcomes: a systematic review and meta-analysis

Objective

We aimed to identify the relationship between maternal prenatal exercise and birth complications, and neonatal and childhood morphometric, metabolic and developmental outcomes.

Design

Systematic review with random-effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were eligible (except case studies and reviews) if published in English, Spanish or French, and contained information on the relevant population (pregnant women without contraindication to exercise), intervention (subjective/objective measures of frequency, intensity, duration, volume or type of exercise, alone (‘exercise-only’) or in combination with other intervention components (eg, dietary; ‘exercise+cointervention’)), comparator (no exercise or different frequency, intensity, duration, volume, type or trimester of exercise) and outcomes (preterm birth, gestational age at delivery, birth weight, low birth weight (<2500 g), high birth weight (>4000 g), small for gestational age, large for gestational age, intrauterine growth restriction, neonatal hypoglycaemia, metabolic acidosis (cord blood pH, base excess), hyperbilirubinaemia, Apgar scores, neonatal intensive care unit admittance, shoulder dystocia, brachial plexus injury, neonatal body composition (per cent body fat, body weight, body mass index (BMI), ponderal index), childhood obesity (per cent body fat, body weight, BMI) and developmental milestones (including cognitive, psychosocial, motor skills)).

Results

A total of 135 studies (n=166 094) were included. There was ‘high’ quality evidence from exercise-only randomised controlled trials (RCTs) showing a 39% reduction in the odds of having a baby >4000 g (macrosomia: 15 RCTs, n=3670; OR 0.61, 95% CI 0.41 to 0.92) in women who exercised compared with women who did not exercise, without affecting the odds of growth-restricted, preterm or low birth weight babies. Prenatal exercise was not associated with the other neonatal or infant outcomes that were examined.

Conclusions

Prenatal exercise is safe and beneficial for the fetus. Maternal exercise was associated with reduced odds of macrosomia (abnormally large babies) and was not associated with neonatal complications or adverse childhood outcomes.

Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis

Objective

Gestational diabetes mellitus (GDM), gestational hypertension (GH) and pre-eclampsia (PE) are associated with short and long-term health issues for mother and child; prevention of these complications is critically important. This study aimed to perform a systematic review and meta-analysis of the relationships between prenatal exercise and GDM, GH and PE.

Design

Systematic review with random effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were included (except case studies) if published in English, Spanish or French, and contained information on the Population (pregnant women without contraindication to exercise), Intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone [“exercise-only”] or in combination with other intervention components [e.g., dietary; “exercise + co-intervention”]), Comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and Outcomes (GDM, GH, PE).

Results

A total of 106 studies (n=273 182) were included. ‘Moderate’ to ‘high’-quality evidence from randomised controlled trials revealed that exercise-only interventions, but not exercise+cointerventions, reduced odds of GDM (n=6934; OR 0.62, 95% CI 0.52 to 0.75), GH (n=5316; OR 0.61, 95% CI 0.43 to 0.85) and PE (n=3322; OR 0.59, 95% CI 0.37 to 0.9) compared with no exercise. To achieve at least a 25% reduction in the odds of developing GDM, PE and GH, pregnant women need to accumulate at least 600 MET-min/week of moderate-intensity exercise (eg, 140 min of brisk walking, water aerobics, stationary cycling or resistance training).

Summary/conclusions

In conclusion, exercise-only interventions were effective at lowering the odds of developing GDM, GH and PE.

Interventions integrating non-communicable disease prevention and reproductive, maternal, newborn, and child health: A systematic review

Reproductive, maternal, newborn, and child health (RMNCH) care services could be critical entry points for preventing non-communicable diseases in women and children. In high-income countries, non-communicable diseases screening has been integrated into both the medical and public health systems. To integrate these services in low- and middle-income countries, it is necessary to closely examine its effectiveness and feasibility. In this systematic review, we evaluated the effectiveness of integrating gestational and non-gestational non-communicable diseases interventions and RMNCH care among women and children in low- and middle-income countries. This systematic review included randomized and quasi-randomized controlled trials published from 2000 to 2015. Participants included reproductive-age women, children < 5 years old, and RMNCH care providers. The included interventions comprised packaged care/services that integrated RMNCH services with non-communicable disease care. The outcomes were maternal and/or infant mortality and complications, as well as health care service coverage. We analyzed six studies from 7,949 retrieved articles. Yoga exercise (p < 0.01) and nutritional improvements (p < 0.05) were effective in reducing gestational hypertension and diabetes. Additionally, integrating cervical cancer and RMNCH services was useful for identifying potential cervical cancer cases. Interventions that integrate non-communicable disease care/screening and RMNCH care may positively impact the health of women and children in low- and middle-income countries. However, as primary evidence is scarce, further research on the effectiveness of integrating non-communicable disease prevention and RMNCH care is warranted. (Review Registration: PROSPERO International prospective register of systematic reviews (CRD42015023425).).

Non-clinical interventions for reducing unnecessary caesarean section

BACKGROUND

Caesarean section rates are increasing globally. The factors contributing to this increase are complex, and identifying interventions to address them is challenging. Non-clinical interventions are applied independently of a clinical encounter between a health provider and a patient. Such interventions may target women, health professionals or organisations. They address the determinants of caesarean births and could have a role in reducing unnecessary caesarean sections. This review was first published in 2011. This review update will inform a new WHO guideline, and the scope of the update was informed by WHO's Guideline Development Group for this guideline.

OBJECTIVES

To evaluate the effectiveness and safety of non-clinical interventions intended to reduce unnecessary caesarean section.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL and two trials registers in March 2018. We also searched websites of relevant organisations and reference lists of related reviews.

SELECTION CRITERIA

Randomised trials, non-randomised trials, controlled before-after studies, interrupted time series studies and repeated measures studies were eligible for inclusion. The primary outcome measures were: caesarean section, spontaneous vaginal birth and instrumental birth.

DATA COLLECTION AND ANALYSIS

We followed standard methodological procedures recommended by Cochrane. We narratively described results of individual studies (drawing summarised evidence from single studies assessing distinct interventions).

MAIN RESULTS

We included 29 studies in this review (19 randomised trials, 1 controlled before-after study and 9 interrupted time series studies). Most of the studies (20 studies) were conducted in high-income countries and none took place in low-income countries. The studies enrolled a mixed population of pregnant women, including nulliparous women, multiparous women, women with a fear of childbirth, women with high levels of anxiety and women having undergone a previous caesarean section.Overall, we found low-, moderate- or high-certainty evidence that the following interventions have a beneficial effect on at least one primary outcome measure and no moderate- or high-certainty evidence of adverse effects.Interventions targeted at women or familiesChildbirth training workshops for mothers alone may reduce caesarean section (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.33 to 0.89) and may increase spontaneous vaginal birth (RR 2.25, 95% CI 1.16 to 4.36). Childbirth training workshops for couples may reduce caesarean section (RR 0.59, 95% CI 0.37 to 0.94) and may increase spontaneous vaginal birth (RR 2.13, 95% CI 1.09 to 4.16). We judged this one study with 60 participants to have low-certainty evidence for the outcomes above.Nurse-led applied relaxation training programmes (RR 0.22, 95% CI 0.11 to 0.43; 104 participants, low-certainty evidence) and psychosocial couple-based prevention programmes (RR 0.53, 95% CI 0.32 to 0.90; 147 participants, low-certainty evidence) may reduce caesarean section. Psychoeducation may increase spontaneous vaginal birth (RR 1.33, 95% CI 1.11 to 1.61; 371 participants, low-certainty evidence). The control group received routine maternity care in all studies.There were insufficient data on the effect of the four interventions on maternal and neonatal mortality or morbidity.Interventions targeted at healthcare professionalsImplementation of clinical practice guidelines combined with mandatory second opinion for caesarean section indication slightly reduces the risk of overall caesarean section (mean difference in rate change -1.9%, 95% CI -3.8 to -0.1; 149,223 participants). Implementation of clinical practice guidelines combined with audit and feedback also slightly reduces the risk of caesarean section (risk difference (RD) -1.8%, 95% CI -3.8 to -0.2; 105,351 participants). Physician education by local opinion leader (obstetrician-gynaecologist) reduced the risk of elective caesarean section to 53.7% from 66.8% (opinion leader education: 53.7%, 95% CI 46.5 to 61.0%; control: 66.8%, 95% CI 61.7 to 72.0%; 2496 participants). Healthcare professionals in the control groups received routine care in the studies. There was little or no difference in maternal and neonatal mortality or morbidity between study groups. We judged the certainty of evidence to be high.Interventions targeted at healthcare organisations or facilitiesCollaborative midwifery-labourist care (in which the obstetrician provides in-house labour and delivery coverage, 24 hours a day, without competing clinical duties), versus a private practice model of care, may reduce the primary caesarean section rate. In one interrupted time series study, the caesarean section rate decreased by 7% in the year after the intervention, and by 1.7% per year thereafter (1722 participants); the vaginal birth rate after caesarean section increased from 13.3% before to 22.4% after the intervention (684 participants). Maternal and neonatal mortality were not reported. We judged the certainty of evidence to be low.We studied the following interventions, and they either made little or no difference to caesarean section rates or had uncertain effects.Moderate-certainty evidence suggests little or no difference in caesarean section rates between usual care and: antenatal education programmes for physiologic childbirth; antenatal education on natural childbirth preparation with training in breathing and relaxation techniques; computer-based decision aids; individualised prenatal education and support programmes (versus written information in pamphlet).Low-certainty evidence suggests little or no difference in caesarean section rates between usual care and: psychoeducation; pelvic floor muscle training exercises with telephone follow-up (versus pelvic floor muscle training without telephone follow-up); intensive group therapy (cognitive behavioural therapy and childbirth psychotherapy); education of public health nurses on childbirth classes; role play (versus standard education using lectures); interactive decision aids (versus educational brochures); labourist model of obstetric care (versus traditional model of obstetric care).We are very uncertain as to the effect of other interventions identified on caesarean section rates as the certainty of the evidence is very low.

AUTHORS' CONCLUSIONS

We evaluated a wide range of non-clinical interventions to reduce unnecessary caesarean section, mostly in high-income settings. Few interventions with moderate- or high-certainty evidence, mainly targeting healthcare professionals (implementation of guidelines combined with mandatory second opinion, implementation of guidelines combined with audit and feedback, physician education by local opinion leader) have been shown to safely reduce caesarean section rates. There are uncertainties in existing evidence related to very-low or low-certainty evidence, applicability of interventions and lack of studies, particularly around interventions targeted at women or families and healthcare organisations or facilities.

Exercise in Pregnancy and Children's Cardiometabolic Risk Factors: a Systematic Review and Meta-Analysis

BACKGROUND

Maternal metabolic health during the prenatal period is an established determinant of cardiometabolic disease risk. Many studies have focused on poor offspring outcomes after exposure to poor maternal health, while few have systematically appraised the evidence surrounding the role of maternal exercise in decreasing this risk. The aim of this study is to characterize and quantify the specific impact of prenatal exercise on children's cardiometabolic health markers, at birth and in childhood.

METHODS

A systematic review of Scopus, MEDLINE, EMBASE, CENTRAL, CINAHL, and SPORTDiscus up to December 2017 was conducted. Randomized controlled trials (RCTs) and prospective cohort studies of prenatal aerobic exercise and/or resistance training reporting eligible offspring outcomes were included. Four reviewers independently identified eligible citations and extracted study-level data. The primary outcome was birth weight; secondary outcomes, specified a priori, included large-for-gestational age status, fat and lean mass, dyslipidemia, dysglycemia, and blood pressure. We included 73 of the 9804 citations initially identified. Data from RCTs was pooled using random effects models. Statistical heterogeneity was quantified using the I2 test. Analyses were done between June and December 2017 and the search was updated in December 2017.

RESULTS

Fifteen observational studies (n = 290,951 children) and 39 RCTs (n = 6875 children) were included. Observational studies were highly heterogeneous and had discrepant conclusions, but globally showed no clinically relevant effect of exercise on offspring outcomes. Meta-analyzed RCTs indicated that prenatal exercise did not significantly impact birth weight (mean difference [MD] - 22.1 g, 95% confidence interval [CI] - 51.5 to 7.3 g, n = 6766) or large-for-gestational age status (risk ratio 0.85, 95% CI 0.51 to 1.44, n = 937) compared to no exercise. Sub-group analyses showed that prenatal exercise reduced birth weight according to timing (starting after 20 weeks of gestation, MD - 84.3 g, 95% CI - 142.2, - 26.4 g, n = 1124), type of exercise (aerobic only, MD - 58.7 g, 95% CI - 109.7, - 7.8 g; n = 2058), pre-pregnancy activity status (previously inactive, MD - 34.8 g, 95% CI - 69.0, - 0.5 g; n = 2829), and exercise intensity (light to moderate intensity only, MD - 45.5 g, 95% CI - 82.4, - 8.6 g; n = 2651). Fat mass percentage at birth was not altered by prenatal exercise (0.19%, 95% CI - 0.27, 0.65%; n = 130); however, only two studies reported this outcome. Other outcomes were too scarcely reported to be meta-analyzed.

CONCLUSIONS

Prenatal exercise does not causally impact birth weight, fat mass, or large-for-gestational-age status in a clinically relevant way. Longer follow up of offspring exposed to prenatal exercise is needed along with measures of relevant metabolic variables (e.g., fat and lean mass).

PROTOCOL REGISTRATION

Protocol registration number: CRD42015029163 .

Physical activity and the risk of preterm birth: a systematic review and meta-analysis of epidemiological studies

BACKGROUND

Physical activity has been inconsistently associated with risk of preterm birth, and the strength of the association and the shape of the dose-response relationship needs clarification.

OBJECTIVES

To conduct a systematic review and dose-response meta-analysis to clarify the association between physical activity and risk of preterm birth.

SEARCH STRATEGY

PubMed, Embase and Ovid databases were searched for relevant studies up to 9 February 2017.

SELECTION CRITERIA

Studies with a prospective cohort, case-cohort, nested case-control or randomized study design were included.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked for accuracy by a second reviewer. Summary relative risks (RRs) were estimated using a random effects model.

MAIN RESULTS

Forty-one studies (43 publications) including 20 randomized trials and 21 cohort studies were included. The summary RR for high versus low activity was 0.87 [95% confidence interval (CI): 0.70-1.06, I² = 17%, n = 5] for physical activity before pregnancy, and it was 0.86 (95% CI: 0.78-0.95, I² = 0%, n = 30) for early pregnancy physical activity. The summary RR for a 3 hours per week increment in leisure-time activity was 0.90 (95% CI: 0.85-0.95, I² = 0%, n = 5). There was evidence of a nonlinear association between physical activity and preterm birth, P_nonlinearity < 0.0001, with the lowest risk observed at 2-4 hours per week of activity.

CONCLUSION

This meta-analysis suggests that higher leisure-time activity is associated with reduced risk of preterm birth. Further randomized controlled trials with sufficient frequency and duration of activity to reduce the risk and with larger sample sizes are needed to conclusively demonstrate an association.

TWEETABLE ABSTRACT

Physically active compared with inactive women have an 10-14% reduction in the risk of preterm birth.

Physical activity in pregnancy and adverse birth outcomes

This study focused on the association between physical activity in the second trimester of pregnancy and adverse perinatal outcomes: low birth weight (LBW), preterm birth (PTB), and intrauterine growth restriction (IUGR). The study used a sample from the BRISA cohort, São Luís, Maranhão State, Brazil, which included women with singleton pregnancy, gestational age from 22 to 25 weeks confirmed by obstetric ultrasound performed at < 20 weeks, and re-interviewed in the first 24 hours postpartum (n = 1,380). Level of physical activity was measured by the International Physical Activity Questionnaire (IPAQ), short version, categorized as high, moderate, and low. A directed acyclic graph (DAG) was used to identify minimum adjustment to control confounding. High physical activity was not associated with LBW (RR = 0.94; 95%CI: 0.54-1.63), PTB (RR = 0.86; 95%CI: 0.48-1.54), or IUGR (RR = 0.80; 95%CI: 0.55-1.15). The results support the hypothesis that physical activity during pregnancy does not result in adverse perinatal outcomes.

Changing trends in management of gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is on the rise globally. In view of the increasing prevalence of GDM and fetal and neonatal complications associated with it, there is a splurge of research in this field and management of GDM is undergoing a sea change. Trends are changing in prevention, screening, diagnosis, treatment and future follow up. There is emerging evidence regarding use of moderate exercise, probiotics and vitamin D in the prevention of GDM. Regarding treatment, newer insulin analogs like aspart, lispro and detemir are associated with better glycemic control than older insulins. Continuous glucose monitoring systems and continuous subcutaneous insulin systems may play a role in those who require higher doses of insulin for sugar control. Evidence exists that favors metformin as a safer alternative to insulin in view of good glycemic control and better perinatal outcomes. As the risk of developing GDM in subsequent pregnancies and also the risk of overt diabetes in later life is high, regular assessment of these women is required in future. Lifestyle interventions or metformin should be offered to women with a history of GDM who develop pre-diabetes. Further studies are required in the field of prevention of GDM for optimizing obstetric outcome.

Predictive biomarkers of pre-eclampsia and effectiveness of preventative interventions for the disease

INTRODUCTION

Pre-eclampsia (PE) is one of the most common pregnancy complication characterized by placental and maternal vascular dysfunction. It affects about 3 - 8% of women during the second half of pregnancy and represents one of the major causes of neonatal morbidity and mortality. The etiology of PE largely remains unknown.

AREAS COVERED

PE is considered a syndrome with multisystem involvement, so the ideal predictive test for it should utilize a combination of many predictors. Measurement in early pregnancy of a variety of biophysical and biochemical markers implicated in the pathophysiology of PE associated with clinical risk factors has been proposed to predict the development of the syndrome, thereby mitigating an adverse outcome.

EXPERT OPINION

The identification of reliable indicators is a clinically relevant issue that could result in early therapeutic intervention and leading to the prevention of maternal and fetal injuries before the manifestation of clinical signs. Many factors complicate the prevention of PE cases. Most are attributed to unknown etiology, the low predictive value of current screening tests and the several presentations of the disease. Although preventative treatments have been studied extensively, an effective intervention to avoid the development of PE has not yet been discovered.