A Virtual Exercise Program throughout Pregnancy during the COVID-19 Pandemic Modifies Maternal Weight Gain, Smoking Habits and Birth Weight—Randomized Clinical Trial

Exercise during pregnancy Dose: Influence on preterm birth outcomes

BACKGROUND

Preterm delivery typically increases health risk for neonates and is associated with longer infant hospital stay and financial burden. Prenatal exercise dose (frequency, intensity, type, time, volume) have been shown to influence birth outcomes. Increased prenatal exercise dose could therefore provide a critical reduction in health risk and financial burden in preterm neonates.

OBJECTIVE

It was our aim to explore the effects of prenatal exercise dose from a supervised exercise intervention in pregnant women on the occurrence of preterm (<37 weeks gestation) births, and the impact on health outcomes in preterm neonates.

STUDY DESIGN

This study is a retrospective, secondary analysis of pooled data from three blinded, prospective, randomized controlled trials. Prenatal exercise dose were assessed in supervised aerobic, resistance, and combination sessions throughout pregnancy. In addition to gestational age, birth weight, resting heart rate, neonatal morphometrics (body circumferences, ponderal index), and health status (Apgar-1 and -5) metrics were obtained for 21 women at birth. One-way analysis of variance tests were used to assess the differences between dose grouped as tertiles, while Pearson correlations determined the association between dose and birth outcomes.

RESULTS

Women exercised for an average of 19.6 wks (range: 6 - 21 wks) during pregnancy. Exercise during pregnancy tended to result in later preterm deliveries (p = 0.08). Greater prenatal exercise volume and duration were associated with reduced infant hospital stay post-delivery (p = 0.02). Weekly exercise volume was associated with increased Apgar scores (p = 0.01).

CONCLUSION

Increased prenatal exercise volume and duration is associated with improved birth outcomes in preterm neonates.

Exercise FITT-V during pregnancy: Association with birth outcomes

BACKGROUND

Prenatal exercise improves birth outcomes, but research into exercise dose-response effects is limited.

METHODS

This study is a retrospective, secondary analysis of pooled data from three blinded, prospective, randomized controlled trials. Prenatal exercise frequency, intensity, type, time, and volume (FITT-V) were assessed in supervised sessions throughout pregnancy. Gestational age (GA), neonatal resting heart rate (rHR), morphometrics (body circumferences, weight-to-length and ponderal index) Apgar and reflex scores, and placental measures were obtained at birth. Stepwise regressions and Pearson correlations determined associations between FITT-V and birth outcomes.

RESULTS

Prenatal exercise frequency reduces ponderal index (R2 = 0.15, F = 2.76, p = .05) and increased total number of reflexes present at birth (R2 = 0.24, F = 7.89, p < .001), while exercise intensity was related to greater gestational age and birth length (R2 = 0.08, F = 3.14; R2 = 0.12, F = 3.86, respectively; both p = .04); exercise weekly volume was associated with shorter hospital stay (R2 = 0.24, F = 4.73, p = .01). Furthermore, exercise type was associated with placenta size (R2 = 0.47, F = 3.51, p = .01).

CONCLUSIONS

Prenatal exercise is positively related to birth and placental outcomes in a dose-dependent manner.

Comparative effect of different types of physical exercise and intensity levels on low birth weight: A systematic review and network meta-analysis

BACKGROUND

Low birth weight (LBW) has been established as a major determinant of neonatal mortality and morbidity. However, there is no evidence of the effectiveness of different types of physical exercise (PE) at different intensities during pregnancy to prevent LBW.

OBJECTIVES

To compare the effectiveness of different types of PE at different levels of intensity in pregnant women to prevent LBW.

DESIGN

A systematic review and network meta-analysis was performed according to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols for Network Meta-Analysis extension statement.

DATA SOURCES AND METHODS

We searched the PubMed, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science databases from inception to November 2023. We included randomized controlled trials (RCTs). A random effects method was used to calculate the pooled mean difference (MD). The effect of each intervention was calculated using a network meta-analysis with a frequentist perspective.

RESULTS

Forty-three RCTs were included in the systematic review, and 38 RCTs were included in the network meta-analysis. In the general population, although no significant results, the MDs for light-moderate strength, moderate-vigorous strength, and moderate-vigorous Pilates exercises were favorable for preventing LBW. Furthermore, moderate-vigorous strength exercise was effective to prevent LBW, reporting significant MD compared to control groups in the healthy population (310.00, 95% confidence interval: 78.40, 541.60; I2 = 81.3%).

CONCLUSION

Strength exercises at a moderate-vigorous intensity could be a potential strategy for the prevention of LBW in the healthy population. However, our findings should be interpreted with caution because the overall risk of bias was between "some concerns" and "high," and the overall certainty of the evidence was low.

REGISTRATION

PROSPERO CRD42023401770.

Influence of Physical Activity during Pregnancy on Neonatal Complications: Systematic Review and Meta-Analysis

Newborn hospitalisations after delivery are indicators of poor neonatal health with potential risks of future diseases for children. Interventions to promote a healthy environment have been used during pregnancy, with physical activity as a principal element. A systematic review and meta-analyses were performed to evaluate the effect of physical activity during pregnancy on neonatal intensive care unit (NICU) admissions and Apgar 1 and 5 scores (Registration No.: CRD42022372493). Fifty studies (11,492 pregnant women) were included. There were significantly different rates of NICU admissions between groups (RR = 0.76, 95% CI = 0.62, 0.93; Z = 2.65, p = 0.008; I2 = 0%, and Pheterogeneity = 0.78), and significant differences in Apgar 1 (Z = 2.04; p = 0.04) (MD = 0.08, 95% CI = 0.00, 0.17, I2 = 65%, Pheterogeneity = 0.00001) and Apgar 5 (Z = 3.15; p = 0.002) (MD = 0.09, 95% CI = 0.04, 0.15, I2 = 80%, and Pheterogeneity = 0.00001), favouring intervention groups. Physical activity during pregnancy could help to reduce the risk of NICU admissions that are related to neonatal complications.

A narrative review of exercise dose during pregnancy

The current recommendations for prenatal exercise dose align with those from the American College of Sports Medicine; 150 min of moderate intensity every week of pregnancy. However, recent works suggest there may be a dose-dependent beneficial effect for mother and offspring; maternal and offspring health outcomes respond differently to low, medium, and high doses of prenatal exercise. It is, therefore, our aim to summarize the published evidence (years 1950-2023) for five metrics of prenatal exercise training commonly reported, that is, "FITT-V": Frequency (number of sessions), Intensity (metabolic equivalents "METs"), Time (duration of sessions), Type (exercise mode), Volume (exercise MET*mins). The target audience includes clinicians and health care professionals, as well as exercise professionals and physiologists. Data suggest that moderate exercise frequency (3-4 times weekly) appears safe and efficacious for mother and offspring, while there is contradictory evidence for the safety and further benefit of increased frequency beyond 5 sessions per week. Moderate (3-6 METs) and vigorous (>6 METs) intensity prenatal exercise have been shown to promote maternal and offspring health, while little research has been performed on low-intensity (<3 METs) exercise. Exercise sessions lasting less than 1 hr are safe for mother and fetus, while longer-duration exercise should be carefully considered and monitored. Taken together, aerobic, resistance, or a combination of exercise types is well tolerated at medium-to-high volumes and offers a variety of type-specific benefits. Still, research is needed to define (1) the "minimum" effective dose of exercise for mother and offspring health, as well as (2) the maximum tolerable dose from which more benefits may be seen. Additionally, there is a lack of randomized controlled trials addressing exercise doses during the three trimesters of pregnancy. Further, the protocols adopted in research studies should be more standardized and tested for efficacy in different populations of gravid women.

Influence of Physical Activity during Pregnancy on Birth Weight: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Birth weight is a marker that is often referred to determine newborn health, potential growth trajectories and risk of future disease. Accordingly, interventions to promote appropriate and healthy birth weight have been extensively studied and implemented in pregnancy. In particular, physical activity in pregnancy is recommended to promote appropriate fetal development and newborn birth weight. This systematic review and meta-analyses aimed to summarize the effect of physical activity during pregnancy specifically from randomized controlled trials on the following outcomes: birth weight, macrosomia, low birth weight, being large for the gestational age, and being small for the gestational age (Registration No.: CRD42022370729). 63 studies (16,524 pregnant women) were included. There was a significant negative relationship between physical activity during pregnancy and macrosomia (z = 2.16; p = 0.03; RR = 0.79, 95% CI = 0.63, 0.98, I2 = 29%, Pheterogeneity = 0.09). No other significant relationships were found. Promoting physical activity during pregnancy may be an opportune time to reduce the risk of future chronic disease, such as obesity, through the prevention of macrosomia and the promotion of appropriate birth weights.

Influence of Physical Activity during Pregnancy on Type and Duration of Delivery, and Epidural Use: Systematic Review and Meta-Analysis

Cesarean delivery may increase the need for anesthesia administration, thereby causing potential risks to both maternal and fetal health. This article aimed to investigate the effect of physical activity during pregnancy on the type of delivery, the duration of labor, and the use of epidurals (registration No.: CRD42022370646). Furthermore, 57 RCTs (n = 15301) were included showing that physical activity could decrease the risk of cesarean section (z = 3.22, p = 0.001; RR = 0.87, 95% CI = 0.79, 0.95, I2 = 37%, Pheterogeneity = 0.004), and 32 RCTs (n = 9468) showed significant decreases in instrumental delivery through performing physical activity (z = 3.48, p < 0.001; RR = 0.84, 95% CI = 0.76, 0.93, I2 = 0%, Pheterogeneity = 0.63). A significant decrease in the 15 RCTs' (n = 4797) duration of first stage labor was found in physically active pregnant women (z = 2.09, p = 0.04; MD = -62.26, 95% CI = -120.66, -3.85, I2 = 93%, Pheterogeneity < 0.001) compared to those not active. Prenatal physical activity could decrease the risk of cesarean section and instrumental delivery and the duration of first stage labor.

Is Exercise during Pregnancy a Risk for Gestational Age and Preterm Delivery? Systematic Review and Meta-Analysis

Traditionally, one of the primary concerns regarding exercise during pregnancy has been the potential of reducing gestational age and increasing the likelihood of preterm delivery. The aim of this study was to perform a systematic review about the effects of physical activity (PA) during pregnancy on gestational age and preterm delivery. A systematic review and two meta-analyses were performed (Registration No. CRD42022370770). Data sources from online databases were searched up to November 2022. The review exclusively included studies involving pregnant populations and interventions consisting of PA implemented during pregnancy. The primary outcomes analysed were gestational age, measured in weeks, and the occurrence of preterm deliveries. A total of 57 studies were analysed through two independent meta-analyses for the first one, no association was found between moderate exercise during pregnancy and gestational age (Z = 0.45, p = 0.65, ES = 0.08, 95% CI = -0.06-0.04, I2 = 42%, P heterogeneity = 0.001), showing the exercise group had a higher gestational age. In addition, no differences were found between groups in terms of number of preterm deliveries (RR = 0.96, (95% CI = 0.77-1.21, Z = 0.33, p = 0.74; ES = 0.07; I2 = 31%, P heterogeneity = 0.05)). The findings of this study indicate that there is no association between exercise during pregnancy and reduced gestational age or increased risk of preterm delivery in healthy pregnancies.

Current Understanding and Future Challenges in Physical Activity during Pregnancy

Obesity and overweight attributed to poor nutrition and a lack of physical activity increasingly become a serious problem among women of reproductive age [...].