Exercise Prescription for Pregnant & Postpartum Women
Clinical Scenario & Introduction
Exercise during a pregnancy has positive effects on both the physical and psychological well-being of the pregnant (PG) woman and fetus (Cooper & Yang, 2019; Chan et al., 2019). Exercise has also proven to decrease the risk of adverse pregnancy outcomes (Watkins et al., 2021). Unfortunately, many PG women still avoid exercise in fear of harming the fetus, due to the lack of guidance and education. Advice from medical professionals in the past has discouraged PG women from exercising due to concerns about premature or low birth weight babies (Williamson, 2019). However, exercise can positively influence and/or prevent several physiological pregnancy conditions, such as preeclampsia, hypertension, low back pain, urinary incontinence, gestational diabetes, pelvic girdle pain, macrosomia or low birth weight, gestational weight gain, cesarean sections, prolonged labor, and other labor complications (Cooper & Yang, 2019; Chan et al., 2019; Filipec & Matijevic, 2022). Exercise can also positively influence several psychological factors such as antenatal/postpartum depression; under this umbrella presents anxiety, sleep deprivation, fatigue, and general stress and mood improvement. The American College of Obstetrics and Gynecology (ACOG) recommends that PG women (with no prior pregnancy contraindications) should participate in 150 minutes of moderate physical activity each week during all three trimesters and the postpartum (PP) period (ACOG, 2019, as cited by McDonald et al., 2022). This 150 minutes can be composed of several different types of exercises including aerobic, resistance, balance, flexibility, and mobility training (Williamson, 2019). However, during pregnancy, a woman's body goes through several physiological and hormonal changes that can affect several factors, including the growth and overall health of the woman and fetus. Exercise can aid in increased oxygen to the maternal and fetal cells. Consequently, this can improve stamina during pregnancy. Also, aerobic and resistance training can help reduce the length of labor and pain associated with pregnancy and delivery. (Williamson, 2019). In fact, previous evidence has shown that newborns who have experienced exercise while in the utero display a lower body fat percentage and normalized birth weight (McDonald et al., 2022). Hence, developing a tailored and progressive exercise program through each stage of pregnancy will aid in a successful pregnancy for both the mother and fetus.
PIO Question
In pregnant (PG) and postpartum (PP) women, what is the correct exercise prescription to aid in overall physical and psychological well-being of the woman and the fetus?
Search Strategy
My search strategy began with identifying the correct key concepts and keywords to search for. The keywords most used for finding relevant articles were the following:
Keywords: pregnancy, healthy pregnancy, exercise prescription, first trimester exercise, second trimester exercise, third trimester exercise, postpartum exercise, antenatal/postpartum depression, gestational weight gain.
Databases: National Library of Medicine, American Journal of Obstetrics and Gynecology, International Journal of Environmental and Public Health, Scientific Reports, Clinical and Experimental Obstetrics and Gynecology, Pubmed
Throughout my search, there were several meta-analyses and systematic reviews. In order to find articles appropriate for the PIO question, I searched the list of citations within each article to find other original researched interventions or trials. Although the databases were useful, most of my research was found through using this method. Also, since my PIO question includes both PG and PP periods, as well as physiological and psychological health, my keywords varied between searches. My inclusion and exclusion criteria remained the same, with differences for the women who were currently PG versus in their PP period.
Inclusion Criteria: PG women at any gestational age of pregnancy (including PP), healthy pregnant women with no prior/current pregnancy contraindications, singleton pregnancy.
Exclusion Criteria: PG women with current adverse pregnancy conditions, non singleton pregnancies.
Evidence Quality Assessment
One of the articles was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE scale). This study included a quasi-experimental design. The remaining four studies were assessed using the Physiotherapy Evidence Database (PEDro scale). These studies included a randomized control study, and three interventions.
Results of search
In order to answer my PIO question, there were several keywords that I used, due to the large umbrella that covers "overall physiological and psychological well being." However, the most success was found through searching citations of meta-analysis’ covering several randomized control trials and interventions. In total, I cited five articles to answer my PIO question. Amongst these articles, all women were anywhere from 8 weeks of gestation to time of delivery. The PP women were 6 weeks to 9 months PP. The ages ranged from 20-39 amongst 3 of the 5 studies. One of the studies had 192 participants with the largest age range of 18-40. The study covering PP health and exercise, did not address the ages of the women who participated. In regard to the inclusion criteria, there were differences amongst the articles covering women who were currently PG, versus those who were in their PP period. For the outcome measures, since "overall health for the woman and fetus” covers a lot of areas, the outcome measures looked at different specific details, but all entailed desirable outcomes for a ‘healthy pregnancy’. In short, the outcome measures for the articles covering women who are currently PG entail a shorter labor time, evaluating the effectiveness of the proposed exercise prescription (motivation, quality of life, lack of contraindications from exercise, lack of fatigue, etc.), reducing the prevalence of gestational diabetes and gestational weight gain, and prevention of anxiety/depression. All studies prescribed an exercise prescription that was deemed appropriate prenatal and PP exercises by several medical and/or exercise professionals. These exercise prescriptions produced positive results in every study. Barakat et al. (2019), McDonald et al. (2022), and Santos-Rocha et al. (2022), all recommended an aerobic capacity of 30-70% depending on the trimester and current fitness level, but had different types of aerobic exercise to accomplish this. Santos-Rocha, et al. (2022) proclaimed that during the first and third trimester, women should ideally keep their target heart rate (THR) between 40-50%. These three studies also prescribed similar resistance exercises incorporating 12-15 repetitions and 2-3 sets. Lastly, there was similar discussion on the importance of stretching, coordination, balance, and pelvic floor strengthening. Wahyuni et al. (2017) focused solely on third trimester exercises, detailing the importance of abdominal and pelvic floor strengthening, and diaphragmatic breathing techniques to reduce the length of labor and anxiety during labor. Lastly, Hatfield et al. (2022) show similar exercise intensities and types to the previous three articles discussed above, but focus more on the positive psychological outcome of the PP women. Additional exercise prescription details are discussed in Clinical Bottom Line and Clinical Implications.
Results of Evidence Quality Assessment
Wahyuni et al. (2017) conducted a Quasi-experimental design and was assessed using the STROBE scale. There was little discussion on how they arrived at the study size or subgroups and interactions, and did not have a control group, therefore receiving a score of 16/20. The remaining four articles were assessed with the PEDro scale. Santos-Rocha et al. (2022) and Hatfield et al. (2022) had no blinding controls for the participants and exercise professionals. They also did not keep the allocation concealed, therefore receiving a score of 6/10. The remaining two studies from McDonald et al. (2022) and Barakat et al. (2019) hit all of the criteria, receiving a score of 10/10.
Clinical bottom line
Exercise during all trimesters of pregnancy and the PP period is completely safe, minus any contraindications. The well-being of the mother and fetus has shown to improve when participating in regular exercise (McDonald et al., 2022; Wahyuni et al., 2017). It is recommended to exercise approximately 150 minutes a week, which should be split up into separate days (McDonald et al., 2022). Aerobically, PG women should keep their heart rates below 70% V02max. During the first trimester and end of the third trimester, it is suggested to keep the target heart rate (THR) between 40-50%. However, if a PG woman was sedentary before pregnancy, THR should start at 30% and progress over time. Aerobic training can be accomplished through running, walking, low impact dance, a series of dynamic movements, cycling, and swimming (Barakat et al., 2019; McDonald et al., 2022; Santos-Rocha et al., 2022). Resistance training remains similar throughout the entire pregnancy, with some adjustments, between trimesters. Typically, women should focus on full body strengthening, with exercises that aid in posture, pelvic floor strength, and stability. It is also essential to train the muscles that are used during labor, including the lower back and lower abdominal musculature (Barakat et al., 2019). Some examples include arm extensions, shoulder elevations, lateral rows, knee extensions, hamstring curls, latissimus dorsi pull downs, tricep extensions, and more. Any movement held in the supine position should be limited to a maximum of 2 minutes, or should be done with an elevated bench (Barakat et al., 2019). Exercises should remain at a light-moderate intensity, with 12-15 repetitions and 2-3 sets. Towards the end of the 2nd trimester until delivery, women should place focus on the strength and flexibility of the pelvic floor muscles, and abdominal wall, to aid in the labor process. This can be accomplished through a quadruped cat/cow, static bird dogs, or a runner's lunge, to name a few (Barakat et al., 2019; Santos-Rocha et al., 2022). Diaphragm breathing is also recommended. These movements will help reduce the total labor time, and prevent potential anxiety and emotional reactions during labor (Wahyuni et al., 2017). Balance and flexibility exercises are also essential, as physiological changes begin to alter a woman's equilibrium. This can be done by performing dynamic and strength movements on a balance pad, or with one foot on the flat ground (i.e., single leg bicep curl) (Santos-Rocha, et al., 2022). During the PP period, women are encouraged to not start exercising until 6-8 weeks after labor (Hatfield et al., 2022). Hatfield et al. (2022) suggested a 45-minute Les Mills TONE workout two times a week, which includes a mix of light to moderate aerobic activity and resistance training. Core exercises can also be included at this stage. While administering these 45-minute workouts, they saw a substantial improvement in women's PP mental health within eight weeks (Hatfield et al., 2022). Based upon the research available, my Strength of Recommendation (SORT) deserves a letter grade of B. I recommend this prescription, but there are certain specifications that should be made depending on the trimester. Also, there is mention of pelvic floor exercises and recovery, but not many trials have been done on the specific mechanisms to aid in this. To see a complete list of these exercises, click here.
Implications for future practice & education
The research demonstrates that exercise can be safe throughout all trimesters of pregnancy and the PP period. Exercise can also help prevent several adverse pregnancy conditions and outcomes. Slight adjustments and additional mechanisms can be added to prescription programs depending on the trimester and current health of the pregnant woman. During the first trimester, rapid cell division and growth, along with extreme hormonal changes take place. This is a very vulnerable time for both the mother and the development of the fetus. At this stage, it is suggested that high intensity or vigorous exercise be minimized (Williamson, 2019). Santos-Rocha, et al. (2022) specifies that women in the first trimester should stay between 40-50% THR. During the second trimester, the placenta is fully functioning, and physiologic changes such as pigmentation changes and abdomen growth become apparent. While nausea and fatigue begin to subside, high levels of progesterone and estrogen can cause congestion and nose bleeds. Also, due to the growth of the fetus, enlargement of the abdomen, and production of relaxin, women can experience an altered center of balance, lack of stability, and back pain (Williamson, 2019). McDonald et al. (2022) and Santos Rocha et al. (2022) incorporate balance exercises, using stability balls, bosu balls, resistance bands, and foam pads. This may involve performing single-leg bicep curls or lateral shoulder raises on a foam pad or Bosu ball. They also detail the importance of incorporating exercises that promote abdominal and pelvic floor muscle strengthening, good posture and back pain prevention. Santos Rocha, et al. (2022) recommends mobility and flexibility with a stability ball, performing pelvic hip stretches, such as a runner's lunge, while using a stability ball for range of motion and support. Finally, during the third trimester, additional pressure is placed on the external organs, due to the growth of the fetus. Excessive constipation and urination takes place, which can make exercise uncomfortable (Williamson, 2019). There are many respiratory and cardiovascular changes that decrease the women's cardiac output by 10-30%, increasing pulse rate by 10-15 beats, and blood pressure fluctuates. There’s also increased oxygen and more efficient alveoli to ensure adequate oxygen delivery to the fetus. An increased metabolism during this time can predispose the woman to hypoglycemia because of the higher demand and utilization of glucose. Hence, it is encouraged to avoid strenuous exercise (Williamson, 2019). Obstetrics & Gynecology (2020) saw that females who performed strenuous exercise during their third trimester were associated with low weight infants of 200-400g less. However, for female athletes, strenuous activity during the third trimester appeared to be safe (Obstetrics & Gynecology, 2020). Santos Rocha, et al. (2022) recommends keeping the THR between 40-50% during this time. Furthermore, Wahyuni et al. (2017) discusses the importance of preparing the abdominal and pelvic floor muscles by increasing their flexibility and strength needed to facilitate labor, while incorporating breathing techniques to eliminate any anxiety or emotional reactions during labor. These exercises are proven to prevent prolonged labors, reducing the risks of pelvic floor injuries, canal lacerations, and cesarean sections to name a few. In many situations, prolonged labor can be caused by irregular contraction, or lack of coordination between contractions, causing stress on the womb. Reducing the labor time can improve the overall health for the mother and fetus (Wang et al., 2022). In regard to the PP period, women are also encouraged to exercise 150 minutes a week of moderate activity. This standard has shown to lower the rate of anxiety and depression in postpartum women (Davenport et al., 2020, as cited by Hatfield et al., 2022). Furthermore, pelvic floor dysfunction is prevalent amongst PP women, so performing pelvic floor recovery exercises is essential to aid in the healing process (Selman et al., 2022).
Future Research
The current clinical trials that have been done on PG and PP women provide a variety of suitable exercises. However, there is limited information on specific adjustments made during certain trimesters. Minus a few recommendations, most of the research done gave prescriptions during multiple trimesters. What's more, during the PP period, there is a lack of research and trials done on specific recovery exercises, especially the pelvic floor. The pelvic floor musculature stretches 250% past its resting length, which can cause pelvic floor dysfunction (Selman et al., 2022). Beyond that, there are several postural changes that include the stretching and shortening of muscles, and several muscular imbalances that can lead to low back pain, sacroiliac dysfunction, and hip pain (Selman et al., 2022). Santos-Rocha, et al. (2022) provides great insight on mobility and flexibility that aid in this, but there is a lack of randomized controlled or clinical trials to show the effectiveness of these exercises on women short and long term. There should be additional research done on preventative and rehabilitative exercises for these several postural changes. What's more, urinary incontinence, low back pain, and general pelvic pain are all prevalent during pregnancy into the PP period. Prescribing deep core exercises can significantly reduce these effects (Selman et al., 2022). Lastly, female mental health is a poorly investigated topic, especially antenatal depression. During pregnancy, there are several social, hormonal, psychological and physiological changes that occur, making females vulnerable to mental health issues during pregnancy. More than 15% of pregnant women report depressive symptoms during pregnancy and it is still undervalued and under investigated (Luciano et al., 2022). Although the studies used in this CAT manuscript touched on mental health, I believe there should be more education on the benefits of exercise and reducing the prevalence of anxiety and depression during pregnancy.
