Summary:
In pregnant women diagnosed with hyperglycemia during pregnancy, a behavioral physical activity intervention promoting unsupervised moderate-intensity walking or stepping in conjunction with clinical medical nutrition therapy significantly mitigated late pregnancy declines in moderate-intensity physical activity compared to the typical reduction seen as pregnancy progresses compared to clinical medical nutrition therapy alone without behavioral physical activity intervention, though it was associated with no serious adverse effects and was deemed acceptable to participants, supporting feasibility for larger trials.
| PICO | Description |
|---|---|
| Population | Pregnant women diagnosed with hyperglycemia during pregnancy, including gestational diabetes mellitus (GDM) and other forms of pregnancy-related glucose intolerance. |
| Intervention | Behavioral physical activity intervention involving unsupervised, moderate-intensity walking or stepping combined with standard clinical medical nutrition therapy for pregnancy hyperglycemia. |
| Comparison | Clinical medical nutrition therapy alone, the standard of care for pregnancy hyperglycemia, without additional behavioral physical activity intervention. |
| Outcome | The intervention effectively mitigated the typical decline in moderate-intensity physical activity that occurs in late pregnancy. It was acceptable to participants and produced no serious adverse effects. Findings support feasibility and warrant investigation in a full-scale randomized controlled trial. |
Clinical Context
Pregnancy hyperglycemia, encompassing gestational diabetes mellitus (GDM) and less severe glucose intolerance, affects approximately 6-15% of pregnancies and is associated with significant maternal and fetal complications. Affected mothers face increased risks of preeclampsia, cesarean delivery, and future type 2 diabetes, while their offspring have elevated risks of macrosomia, birth injury, neonatal hypoglycemia, and long-term metabolic dysfunction. Medical nutrition therapy (MNT) is the cornerstone of management, but many women require additional interventions to achieve glycemic targets.
Physical activity improves insulin sensitivity and glycemic control, but pregnant women with hyperglycemia often reduce their activity levels as pregnancy progresses. This decline is multifactorial: physical discomfort, fatigue, fear of harm to the fetus, and conflicting advice about exercise safety during pregnancy all contribute. By the third trimester, when hyperglycemia is most difficult to control due to maximal insulin resistance, physical activity levels are typically at their nadir.
Behavioral interventions that specifically target maintenance of physical activity during late pregnancy could address this gap. Walking and stepping are low-risk, accessible activities that most pregnant women can perform without specialized equipment or supervision. This pilot study tested whether a behavioral intervention promoting these activities could prevent the typical late-pregnancy activity decline in women with pregnancy hyperglycemia.
Clinical Pearls
1. Intervention Prevented Activity Decline Rather Than Increasing Activity: The primary effect was mitigating the usual reduction in physical activity during late pregnancy rather than producing absolute increases above baseline. Maintaining activity levels as pregnancy progresses may be a more realistic and achievable goal than expecting activity increases in late gestation.
2. Unsupervised Activity Is Feasible and Safe: The intervention promoted self-directed walking and stepping without requiring supervised exercise sessions. No serious adverse effects occurred, supporting the safety of moderate-intensity physical activity in pregnancy hyperglycemia when appropriately counseled.
3. Acceptability Supports Scalability: Participant acceptance of the intervention is crucial for real-world implementation. The feasibility and acceptability demonstrated here suggest the approach could be scaled for broader clinical use pending efficacy confirmation in larger trials.
4. Behavioral Support Adds Value Beyond Medical Advice: Standard care typically includes general advice to remain active, but structured behavioral intervention produced better activity maintenance. The behavioral components—goal-setting, self-monitoring, problem-solving barriers—appear to translate generic advice into sustained behavior.
Practical Application
For pregnant patients with hyperglycemia, incorporate specific behavioral counseling to maintain physical activity throughout pregnancy, particularly as they enter the third trimester. Frame the goal as preventing activity decline rather than expecting activity increases, which may be more achievable and less discouraging for patients experiencing pregnancy-related physical limitations.
Recommend walking and stepping as accessible, low-risk activities that require no special equipment or supervision. Provide guidance on warning signs requiring activity cessation (vaginal bleeding, contractions, dizziness, shortness of breath before exertion) while reassuring patients that moderate activity is generally safe and beneficial.
Consider using behavioral techniques such as activity tracking (pedometers or smartphone apps), specific weekly goals, and problem-solving discussions about barriers. Brief counseling at each prenatal visit can reinforce activity maintenance as an integral component of hyperglycemia management alongside dietary modification.
Broader Evidence Context
This pilot trial adds to evidence supporting physical activity for pregnancy hyperglycemia management. Previous studies have demonstrated that exercise improves glycemic control in GDM, but most interventions involved supervised exercise programs with limited scalability. The focus on behavioral support for unsupervised activity represents a more practical approach for widespread implementation.
Current guidelines recommend physical activity for GDM management, but specific guidance on maintaining activity in late pregnancy and behavioral strategies to achieve this is limited. This study provides preliminary evidence to inform more detailed recommendations pending confirmatory trials.
Study Limitations
As a pilot study, sample size was insufficient to detect effects on glycemic outcomes or pregnancy complications. Glycemic control and neonatal outcomes were not primary endpoints. Self-reported physical activity is subject to recall and social desirability bias. Generalizability to diverse populations requires confirmation.
Bottom Line
A behavioral intervention promoting walking and stepping prevents the typical late-pregnancy decline in physical activity among women with pregnancy hyperglycemia, demonstrating feasibility, acceptability, and safety that support larger trials to evaluate glycemic and pregnancy outcomes.
Source: Ehrlich, Samantha F., et al. “A Randomized Controlled Pilot Trial of a Behavioral Physical Activity Intervention for Pregnancy Hyperglycemia.” Read article
