Gestational Age and Cardiorespiratory Fitness in Individuals Born At Term: A Life Course Study

Trial of labor versus elective cesarean delivery for patients with two prior cesarean sections: a systematic review and meta-analysis

OBJECTIVE

Cesarean section (CS) rates have been on the rise globally, leading to an increasing number of women facing the decision between a Trial of Labor after two Cesarean Sections (TOLAC-2) or opting for an Elective Repeat Cesarean Section (ERCS). This study evaluates and compares safety outcomes of TOLAC and ERCS in women with a history of two previous CS deliveries.

METHODS

PubMed, MEDLINE, EMbase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for studies published until 30 June 2023. Eligible studies were included based on predetermined criteria, and a random-effects model was employed to pool data for maternal and neonatal outcomes.

RESULTS

Thirteen studies with a combined sample size of 101,011 women who had two prior CS were included. TOLAC-2 was associated with significantly higher maternal mortality (odds ratio (OR)=1.50, 95% confidence interval (CI)= 1.25-1.81) and higher chance of uterine rupture (OR = 7.15, 95% CI = 3.44-14.87) compared to ERCS. However, no correlation was found for other maternal outcomes, including blood transfusion, hysterectomy, or post-partum hemorrhage. Furthermore, neonatal outcomes, such as Apgar scores, NICU admissions, and neonatal mortality, were comparable in the TOLAC-2 and ERCS groups.

CONCLUSION

Our findings suggest an increased risk of uterine rupture and maternal mortality with TOLAC-2, emphasizing the need for personalized risk assessment and shared decision-making by healthcare professionals. Additional studies are needed to refine our understanding of these outcomes in the context of TOLAC-2.

Cardiorespiratory fitness and physical activity in the lens of social justice - Reporting on the disparities that exist

Cardiorespiratory fitness (CRF), heavily influenced by physical activity (PA), represents a strong and independent risk factor for a wide range of health conditions, most notably, cardiovascular disease. Substantial disparities in CRF have been identified between white and non-white populations. These disparities may partly account for group differences in susceptibility to poor health outcomes, including non-communicable disease. Race and ethnic differences in CRF may partly be explained by social injustices rooted in persistent structural and systemic racism. These forces contribute to environments that are unsupportive for opportunities to achieve optimal CRF levels. This review aims to examine, through the lens of social justice, the inequities in key social ecological factors, including socioeconomic status, the built environment, and structural racism, that underly the systemic differences in CRF and PA in vulnerable communities. Further, this review highlights current public health initiatives, as well as opportunities in future research, to address inequities and enhance CRF through the promotion of regular PA.

HAPI Fit: An Exercise Intervention to Improve Peak Aerobic Capacity in Young Adults Born Very Preterm

INTRODUCTION

Individuals born preterm have reduced aerobic capacity, which could be related to impaired organ development. Their capacity to improve aerobic capacity with exercise training could therefore be limited, but this remains unknown. We aimed to test an exercise intervention to improve cardiorespiratory fitness in adults born preterm.

METHODS

Twenty-one very preterm and 37 full-term individuals aged 18-33 yr took part in a 14-wk supervised exercise intervention of cardiovascular, resistance, and flexibility training (two group and one individual sessions per week). Adherence and compliance to intervention were recorded. Primary outcome was change in peak oxygen consumption (peak V̇O 2 ) measured before and after the intervention. Within- and between-group differences were estimated using nonparametric tests.

RESULTS

Of 219 eligible individuals, 58 were enrolled and 14 participants dropped out over the course of the intervention. Among the 44 who completed the intervention, mean adherence was 82% and 66% for group and individual sessions, respectively. Compliance with training requirement varied between 71% and 100%. There was no difference in adherence between the preterm and full-term groups. Because only one preterm male met the adherence criteria, subsequent analyses were done exclusively on females. Both the term and preterm groups achieved higher peak V̇O 2 after the intervention [term = +4.2 (SD 4.3) mL·min -1 ·kg -1 , P < 0.01; preterm = +4.7 (2.9) mL·min -1 ·kg -1 , P < 0.01]. There was no between-group difference in the response to the intervention ( P = 0.729).

CONCLUSIONS

Recruitment and adherence to an exercise intervention are challenging. Results could indicate improvements in cardiorespiratory fitness in young women born preterm after current exercise program. Adaptation of this intervention is needed for wider uptake.

Influence of preterm birth on physical fitness in early childhood

Evidence suggests that preterm birth is associated with an impaired physical fitness later in life, but whether these effects are already visible since early childhood remains unknown. We aimed to compare the physical fitness of preterm preschoolers with that of children born at term. Children aged three to six years and born preterm (<35 weeks) were recruited from a Neonatal Intensive Care Unit, and children born at term (>37 weeks) were included as controls. A variety of physical fitness indicators (strength, cardiorespiratory fitness, agility, flexibility and balance) were assessed with the PREFIT battery and the adapted sit and reach test. Physical activity levels were measured through the PrePAQ questionnaire. A total of 98 preterm children (gestational age 32.4 ± 2.3 weeks, age 5.1 ± 0.8 years) and 74 controls (gestational age 39.9 ± 1.0 weeks, age 4.8 ± 0.9 years) were analysed. Despite no significant differences in physical activity levels (p > 0.05), preterm children showed an overall poorer physical fitness compared to controls. Specifically, preterm children had an impaired handgrip strength (-13.95%, p < 0.001), lower-limb muscle strength (-12.67%, p = 0.003), agility (-14.9%, p = 0.001), cardiorespiratory fitness (-12.73% p = 0.005) and flexibility (-17.04%, p = 0.001) compared to controls. An inverse dose-response association was observed between the level of prematurity and physical fitness, with very preterm children (gestational age ≤32 weeks) presenting the poorest fitness levels. In summary, prematurity seems to impair physical fitness since early childhood, which might support the need for promoting preventive strategies (e.g. fitness monitoring and applying exercise interventions).Highlights Preterm children present an impaired physical fitness compared with peers born at term since early childhood (3-6 years), as reflected by lower muscle strength, agility, flexibility and cardiorespiratory fitness.A greater impairment of physical fitness in observed in children born very preterm (≤32 weeks of gestation).These findings might support the implementation of preventive strategies (e.g. fitness monitoring and exercise training) in preterm children since early childhood.

Uncharted territory: a narrative review of parental involvement in decision-making about late preterm and early term delivery

Almost 30% of live births in England and Wales occur late preterm or early term (LPET) and are associated with increased risks of adverse health outcomes throughout the lifespan. However, very little is known about the decision-making processes concerning planned LPET births or the involvement of parents in these. This aim of this paper is to review the evidence on parental involvement in obstetric decision-making in general, to consider what can be extrapolated to decisions about LPET delivery, and to suggest directions for further research.A comprehensive, narrative review of relevant literature was conducted using Medline, MIDIRS, PsycInfo and CINAHL databases. Appropriate search terms were combined with Boolean operators to ensure the following broad areas were included: obstetric decision-making, parental involvement, late preterm and early term birth, and mode of delivery.This review suggests that parents' preferences with respect to their inclusion in decision-making vary. Most mothers prefer sharing decision-making with their clinicians and up to half are dissatisfied with the extent of their involvement. Clinicians' opinions on the limits of parental involvement, especially where the safety of mother or baby is potentially compromised, are highly influential in the obstetric decision-making process. Other important factors include contextual factors (such as the nature of the issue under discussion and the presence or absence of relevant medical indications for a requested intervention), demographic and other individual characteristics (such as ethnicity and parity), the quality of communication; and the information provided to parents.This review highlights the overarching need to explore how decisions about potential LPET delivery may be reached in order to maximise the satisfaction of mothers and fathers with their involvement in the decision-making process whilst simultaneously enabling clinicians both to minimise the number of LPET births and to optimise the wellbeing of women and babies.

Temporal association of maternal weight gain with early-term and preterm birth and low birth weight babies

BACKGROUND

Low birth weight and preterm or early-term babies may have a higher risk of poor health. One of the main factors is the weight gain of a pregnant woman during gestational weeks in the second and third trimesters. Changes in weight over a month in a pregnant woman might also have an impact on infant outcomes. This study aimed to investigate the association between maternal weight at different time points and low birth weight and preterm or early-term babies (premature babies).

METHODS

A total of 156 pregnant women were recruited. Maternal weight was collected at different gestational weeks. Maternal age, body mass index, delivery mode, delivery week, and infant weight were also recorded. Maternal data were restructured into a person-period format before mixed-effects multiple logistic regression was used. Various weight variables with either a fixed effect or time-varying effects were tested in the model.

RESULTS

Thirty (19.23%) women had delivered low birth weight or premature babies. Multiple logistic regression model demonstrated that mothers with higher increases in weight at 32 weeks of gestation than that in the predelivery stage had a lower probability of having a low birth weight or premature baby (odds ratio [OR] = 0.64; 95% CI, 0.49-0.85; p < 0.001). Women with a weight increase of more than 2 kg in a 4-week gestation period had a higher probability of having a low birth weight or premature baby than those with an increment of <1 kg (OR = 8.43; 95% CI, 2.90-24.54; p < 0.001).

CONCLUSION

An increase in weight gain after 32 weeks was shown to reduce the risk of low birth weight and premature babies. Maternal weight monitoring was suggested to be conducted every 4 weeks to minimize the chance of having a low birth weight and premature baby.

Sedentary behaviour and physical activity across pregnancy and birth outcomes

BACKGROUND

Shorter gestation or smaller birth size are indicators of a suboptimal fetal environment and negatively impact short- and long-term offspring health. Understanding how modifiable maternal behaviours, such as moderate-to-vigorous intensity physical activity (MVPA) or sedentary behaviour (SED), improve fetal outcomes could inform strategies to improve health across the lifespan.

OBJECTIVES

The objective of this study was to examine the association of MVPA and SED across pregnancy trimesters on gestational age at delivery and newborn anthropometrics.

METHODS

The MoM Health Study measured SED (thigh-mounted activPAL3 micro) and MVPA (waist-worn Actigraph GTX3) in each trimester of pregnancy. Birth outcomes (gestational age at delivery, birthweight, birth length, and head circumference) were abstracted from medical records and used to calculate ponderal index (grams*100/cm³ ) and size-for-gestational age percentiles. Associations of group-based trajectories and trimester-specific SED and MVPA with birth outcomes were analysed using regression models.

RESULTS

Low, medium, and high trajectory groups were generated SED and MVPA in 103 and 99 pregnant women, respectively. High vs low SED trajectory was associated with earlier gestational age at delivery (β -1.03 weeks, 95% CI -2.01, -0.06), larger head circumference (β 0.83 cm, 95% CI 0.24, 1.63), longer birth length (β 1.37 cm, 95% CI 0.09, 2.64), and lower ponderal index (β -0.24 g*100/cm³ , 95% CI -0.42, -0.06), after adjustment for demographics, pre-pregnancy BMI, and (for newborn anthropometric outcomes) gestational age. The association of high SED with lower ponderal index was the most robust across progressively adjusted models (β -0.25 g*100/cm³ , 95% CI -0.44, -0.07). SED trajectory was not associated with birthweight or size-for-gestational age. High vs low MVPA trajectory was only associated with smaller head circumference (β -0.86 cm, 95% CI -1.70, -0.02).

CONCLUSIONS

Higher SED during pregnancy may result in shorter gestation and inhibited fetal growth. Further research evaluating the effect of reducing SED during pregnancy on birth outcomes is warranted.

Low birth weight and its relation to physical fitness parameters in children: Its negative effect on muscle strength and cardiorespiratory endurance

BACKGROUND

There is increasing evidence that low birth weight has a negative effect on physical fitness, muscle strength, and cardiorespiratory endurance, although the findings are inconsistent.

OBJECTIVES

This study aimed to evaluate whether birth weight acts as a prenatal determinant of physical fitness parameters and to determine the role of environmental or biological variables on this effect.

METHODS

One hundred and sixty-seven children aged 6-14 years were included in this study. The anthropometric data, physical activity index, standing long jump, flexibility, handgrip strength, and cardiorespiratory fitness were evaluated.

RESULTS

A positive correlation was found between birth weight and cardiorespiratory fitness (r = .349; p < .001), right handgrip strength (r = .337; p < .001), and left handgrip strength (r = .320; p < .001), suggesting that children with low birth weight had the worst performance in both cardiorespiratory endurance and grip strength tests. These findings remained significant after adjustment for prematurity, sex, age, physical activity index, and body mass index (BMI). Stepwise multiple regression analyses revealed a significant interaction of high birth weight, older age, and low BMI in predicting better cardiorespiratory endurance (R² = .308). When handgrip strength was tested as the dependent variable, we found that high birth weight, male sex, and older age emerged as important determinants for both sides.

CONCLUSION

Children aged 6-14 years born with a birth weight < 2.5 kg have low handgrip strength and cardiorespiratory fitness, which seems to be mediated partially by influences of both prenatal environment (e.g., birth weight) and biological variables (e.g., age, sex, BMI).

The association between birth by cesarean section and adolescent cardiorespiratory fitness in a cohort of 339,451 Swedish males

Birth by cesarean section is increasing worldwide and associates with offspring morbidities capable of adversely impacting cardiorespiratory fitness later in life. Whether birth by cesarean section associates with lower levels of cardiorespiratory fitness later in life is unknown and is of interest to public health. Four Swedish national registers were linked to follow 339,451 singleton males, born between 1973–1987 until December 31 2005, for Watt-maximum achieved on a cycle ergometer test at conscription into the Swedish military. Main exposure was birth by cesarean section which was compared to vaginal birth. A sub-population of 45,999 males born between 1982–1987 was identified to explore differentiated associations between elective and non-elective cesarean section with Watt-maximum. Within-family analyses of 34,252 families with 70,632 biological male siblings, who conscripted during the study period, were performed to explore the role of familial confounding on Watt-maximum. Swedish males born by cesarean section achieved lower mean Watt-maximum (− 2.32 W, 95%C.I. − 2.90 to − 1.75) and displayed excess odds of low cardiorespiratory fitness (aOR = 1.08, 95%C.I. 1.05 to 1.11) at conscription in the eighteenth life-year compared to males born vaginally after adjusting for birth characteristics, maternal morbidities and parental socioeconomic position. In the sub-population, males born 1982–1987, there was a greater negative association of elective cesarean section with cardiorespiratory fitness (− 4.42 W, 95%C.I. − 6.27 to − 2.57, p < 0.001) than non-elective cesarean sections (− 1.96 W, 95%C.I. − 3.77 to − 0.16, p = 0.033) as compared to vaginal births. No associations between modes of cesarean delivery and cardiorespiratory fitness levels persisted in the within-family analyses where biological male siblings were compared whilst controlling for factors shared within families. Males born by cesarean section had lower levels of cardiorespiratory fitness eighteen years later compared to males born vaginally. These findings appear to be largely explained by factors of familial confounding.

Vaginal Birth after Two Previous Cesarean Sections versus Elective Repeated Cesarean: A Retrospective Study

OBJECTIVE

Trial of labor after cesarean delivery (TOLAC) is a common practice worldwide but the evidence is still scant regarding this practice in women who underwent 2 previous cesareans. The purpose of this study is to retrospectively review our experience with vaginal birth after two previous cesarean sections (VBA2C), with specific attention to the indications for previous cesarean and to the women's motivation for attempting trial of labor.

STUDY DESIGN

This was a retrospective cohort study conducted in a primary care hospital between January 2011 and December 2019. Inclusion criteria were: singleton pregnancies, absence of morphological abnormalities at ultrasonographic screening of the second trimester (or at any other stage of pregnancy), and two previous cesarean sections.

RESULTS

The final analysis included 114 cases for maternal and neonatal outcomes. In total, 40.4% of women chose trial of labor after two cesarean delivery (TOLA2C group). TOLA2C was associated with a success rate of 76.1%, a higher gestational age at birth, and a shorter hospital stay, compared with elective repeated cesarean delivery group. There were no significant differences in the rate of Apgar scores at 5 minutes <7 between both groups. The percentage of successful TOLA2C in women with prior vaginal delivery was 92.8%. Factors related to failed TOLA2C included failure to progress (3/11, 27.3%), nonreassuring fetal heart rate (3/11, 27.3%), and no onset of spontaneous labor after premature rupture of membranes (5/11, 45.4%). In the group of TOLA2C, more than 70% accepted to travel more than 45 minutes to reach our hospital, with the aim to attempt VBA2C.

CONCLUSION

TOLA2C is a possible option for both mothers and neonates in selected cases. Adequate counseling about pros and cons of TOLA2C is mandatory. The woman's motivation represents a key element to determine the success of VBA2C.

KEY POINTS

· Selection of candidates and motivation of the patients represent key elements for successful TOLA2C.. · A careful record of obstetrical history and previous deliveries can provide clinicians useful information.. · Mode of delivery in women with two previous cesareans is strongly associated with doctor's counseling..

Cardiorespiratory Fitness in Youth: An Important Marker of Health: A Scientific Statement From the American Heart Association

Cardiorespiratory fitness (CRF) refers to the capacity of the circulatory and respiratory systems to supply oxygen to skeletal muscle mitochondria for energy production needed during physical activity. CRF is an important marker of physical and mental health and academic achievement in youth. However, only 40% of US youth are currently believed to have healthy CRF. In this statement, we review the physiological principles that determine CRF, the tools that are available to assess CRF, the modifiable and nonmodifiable factors influencing CRF, the association of CRF with markers of health in otherwise healthy youth, and the temporal trends in CRF both in the United States and internationally. Development of a cost-effective CRF measurement process that could readily be incorporated into office visits and in field settings to screen all youth periodically could help identify those at increased risk.

Reasons for previous Cesarean deliveries impact a woman's independent decision of delivery mode and the success of trial of labor after Cesarean

BACKGROUND

Cesarean delivery rates are increasing globally with almost half of them occurring due to a previous Cesarean delivery. A trial of labor after Cesarean (TOLAC) is considered a safe procedure, but most eligible women instead undergo Cesarean before 39 weeks of gestation. Lack of education about TOLAC is often associated with increased repeat Cesarean. To reveal the safety and feasibility of TOLAC, we conducted this observational, prospective study with women's independent decisions. We aimed to clarify the relationship between their chosen mode of delivery and the reason for their previous Cesarean. Additionally, we have tried to identify maternal and obstetric factors associated with failed TOLAC to improve its success rate.

METHODS

This was a prospective, observational study of 1086 pregnant women with at least one previous Cesarean delivery. Of these, 735 women met our TOLAC criteria (Table 1), and then, could choose TOLAC or repeat Cesarean after receiving detailed explanations regarding the risks and benefits of both procedures. The primary outcomes were the number of successful TOLAC procedures and 5-min Apgar scores < 7 for the trial of labor after Cesarean group and elective Cesarean group. We collected the maternal and neonatal data including the reasons of previous Cesarean.

RESULTS

In total, 64.1% of women chose TOLAC. The success rate was 91.3%. The uterine rupture rate was 0.6%. There were no significant differences in the rate of Apgar scores at 5 min < 7 between both groups. Histories of experience of labor in previous Cesarean delivery were observed in 30 and 50% of women who chose TOLAC and repeat Cesarean, respectively (p < 0.05). Factors related to failed TOLAC included ≥40 weeks of gestation (odds: 5.47, 95% CI: 2.55-11.70) and prelabor rupture of membranes (PROM) (odds: 4.47, 95% CI: 2.07-9.63).

CONCLUSIONS

TOLAC is a favorable delivery option for both mothers and neonates when women meet criteria and choose after receiving detailed explanations. Women who experience PROM or ≥ 40 weeks of gestation, their modes of delivery should be reconsulted.

Birth Weight and Cardiorespiratory Fitness Among Young Men Born at Term: The Role of Genetic and Environmental Factors

Background Preterm delivery and low birth weight are prospectively associated with low cardiorespiratory fitness (CRF). However, whether birth weight, within the at-term range, is associated with later CRF is largely unknown. Thus, the aim of the current study was to examine this issue and whether such association, if any, is explained by shared and/or nonshared familial factors. Methods and Results We conducted a prospective cohort study, including 286 761 young male adults and a subset of 52 544 siblings born at-term. Objectively measured data were retrieved from total population registers. CRF was tested at conscription and defined as the maximal load obtained on a cycle ergometer. We used linear and nonlinear and fixed-effects regression analyses to explore associations between birth weight and CRF. Higher birth weight, within the at-term range, was strongly associated with increasing CRF in a linear fashion. Each SD increase in birth weight was associated with an increase of 7.9 (95% CI, 7.8-8.1) and 6.6 (95% CI; 5.9-7.3) Wmax in the total and sibling cohorts, respectively. The association did not vary with young adulthood body mass index. Conclusions Birth weight is strongly associated with increasing CRF in young adulthood among men born at-term, across all categories of body mass index. This association appears to be mainly driven by factors that are not shared between siblings. Hence, CRF may to some extent be determined already in utero. Prevention of low birth weight, also within the at-term-range, can be a feasible mean of increasing adult CRF and health.