Gestational diabetes mellitus (GDM), defined as ‘glucose
intolerance and insulin resistance first detected during pregnancy. In more
than 50% of cases, GDM may progress to type 2 diabetes mellitus, hypertension
and cardiovascular diseases within 5–15 years after pregnancy. Additionally,
GDM is associated with several maternal and perinatal complications such as
hypertensive disorders of pregnancy (HDP), which include gestational hypertension
(GH), pre-eclampsia and eclampsia, affecting 10% of pregnancies. Likewise, HDP
are associated with higher life-long cardiovascular risk. Otherwise, fetal
overgrowth or macrosomia is one of the fetal complications that occur in up to
45% of GDM pregnancies. These babies have an increased risk of overweight,
obesity and type 2 diabetes later in life.
Several studies have suggested that exercise is an effective
strategy for preventing and treating diabetes and hypertension in the general
population by reducing some of the mechanisms involved in inflammation,
oxidative stress and endothelial dysfunction, all of which are
pathophysiological mechanisms involved in the genesis of HDP and GDM. That, in turn,
is associated with obesity and physical inactivity. However, the evidence about
the effectiveness of exercise in avoiding the development of both disorders
during pregnancy is still not consistent. Some reviews reported that physical
activity (PA) programmes produced reductions in the prevalence of GDM.
Umbrella review carried by Martínez-Vizcaíno V,
Sanabria-Martínez G, Fernández-Rodríguez R et al aimed to provide a comprehensive
overview of the effect of exercise interventions during pregnancy on GDM and
HDP. 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. 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.
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.
Based on 21 systematic reviews and meta-analyses, and 54
RCTs, authors found that exercise interventions were more effective than
standard prenatal care in reducing the incidence of GDM and GH by 39% and 47%,
respectively. In contrast, subgroup analyses showed no effect of exercise on
the incidence of HDP in overweight and obese pregnant women or when sessions
lasted less than 45 minutes.
Meanwhile, study data suggest that exercise is more
effective in reducing the GDM and HDP incidence when initiated in the first
trimester of pregnancy, under supervision and with light to moderate intensity,
whereas exercise only reduced the incidence of preeclampsia when pregnant women
started exercise in the first trimester of pregnancy. Trial sequence analysis
indicates that additional studies are needed to elucidate the effect of PA
interventions on pre-eclampsia incidence.
In summary, the current evidence supports that exercise has
a beneficial effect on the incidence of GDM and GH in non– overweight or obese
pregnant women. Furthermore, these benefits are greater when exercise
interventions are supervised, have a low to moderate intensity level, and are
initiated during the first trimester of pregnancy.
Nevertheless, more high-quality intervention studies are
needed to accurately evaluate the safety and benefits of exercise programmes
for specific pregnant populations, such as women with overweight and obesity,
and whether higher intensity exercise interventions result in greater benefits
in these groups. In addition, according to this data, to achieve greater
benefits, the core of recommendation for clinicians is that exercise should be
supervised, initiated in the first trimester of pregnancy, and lasting more
than 45 minutes per session. However, few studies have reported a reduction in
HDP among women with overweight and obesity. More studies are needed to test
the effectiveness of exercise interventions to reduce the incidence of
pre-eclampsia in pregnant women with excess weight.
Source: Martínez-Vizcaíno
V, Sanabria-Martínez G, Fernández-Rodríguez R, Cavero-Redondo I, Pascual-Morena
C, Álvarez-Bueno C, et al. Exercise during pregnancy for preventing gestational
diabetes mellitus and hypertensive disorders: An umbrella review of randomised
controlled trials and an updated meta-analysis. BJOG. 2022;00:1–12.
https://doi.org/10.1111/1471-0528.17304