Does Exercising in Pregnancy Really Cause Women to Miscarry?
Nicole zakhour
Kaplan university
Clinical question
Does moderate exercise increase the rate of miscarriages in pregnancy?
PICOt question
In pregnancy, how does exercise, compared to a sedentary lifestyle, affect the risk or likelihood of miscarriages, within the first trimester?
Database and keywords
MEDLINE database:
Words searched: risks associated with miscarriage, exercise in pregnancy, first trimester loss, risks of exercising while pregnant, miscarriage and exercise
Cochrane Database:
Words searched: Miscarriage, exercise, pregnancy, first trimester
Level 1 evidence
Cochrane Database:
Level 1: “Evidence from a systematic review or meta-analysis of all relevant RCT’s” (Melynk & Fineout-Overholt, 2015, p. 11)
Studies:
1) Does bedrest decrease the risk for miscarriages? (Aleman, Athabe, Belizán, & Bergel, 2005)
2) Are there effective treatments in Chinese medicine to treat unexplained, recurrent miscarriages? (Li, Dou, Leung, Chung, & Wang, 2016)
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Level 1 statistics
Study 1: Does bedrest effect the rate of miscarriages? Data collected determined the risk of miscarriage in a normal pregnancy, is not effected by bedrest. One will miscarry if they have chromosomal abnormalities and activity does not make one more prone to a loss.
Study including 84 women: RR 1.54, 95% & CI 0.92 to 2.58
Miscarriages happen in 10-15% of pregnancies
2/3 of miscarriages are associated with chromosomal defects
Limitations: Not enough evidence to determine the risk for miscarriage with exercise. Statistics proved that miscarriages are more likely to occur due to chromosomal defect than exercise.
(Aleman et al., 2005)
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Level 1 statistics continued
Study 2: Determined that Chinese medicine works better for reducing the number of miscarriages than Western medicine alone. Miscarriages occur for unknown reasons. Information only touched upon keeping the pregnancy, rather then risks associated with miscarriage due to the unknown etiology.
44 RCT’s with 5100 women
Chinese medicine has an increased rate of continuing a pregnancy versus Western medicine alone: RR 1.28; 95% CI 1.18-1.38 in 5 trials with 550 women.
Limitations: Not enough evidence to determine the risk for miscarriage with exercise.
Limitations: Not enough evidence to determine the risk for miscarriage with exercise.
(Li et al., 2016)
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Level ii evidence
MEDLINE database:
Level 2: “Evidence obtained from well-designed RCT’s” (Melynk & Fineout-Overholt, 2015, p. 11)
Studies:
1) Benefits of exercise on pregnancy (Kader & Naim-Schuchana, 2014)
2) Benefits of exercise on pregnancy and disputing potential harms associated with exercise in pregnancy (Kuhrt, Hezelgrave , & Shennan, 2015)
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Level ii statistics
Study 1:
Moderate activity does not increase the risk for adverse effects in pregnancy
High risk sports should be avoided due to the risk of injury to abdomen
Moderate exercise at 30 min/day, at least 3 times a week is recommended
RCT: 87,232 women- Trained women had almost 40% reduced risk of preterm birth (OR 0.82, 95% CI 0.76 – 0.88). The association was not affected by the type of exercise
RCT: 148 women- Exercised women improved aerobic fitness ( p 0.05), muscular strength ( p 0.01), fewer caesarean deliveries ( p 0.01), and recovered faster postpartum ( p 0.05)
RCT: 166 women- A lower frequency of macrosomia in newborns (6.0% vs 12.5%, p = 0.048) and gestational diabetes (1.8% vs 8.3%, p = 0.008)
Limitations: none. Proved that exercise does not induce miscarriage
(Kader & Naim-Schuchana, 2014)
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Level ii statistic continued
Study 2:
Ruled out potential harms of exercising while pregnant:
Miscarriages do not occur due to moderate exercise
Preterm birth:
Systematic Review, 11 trials, 472 women, 20-50 % decrease in preterm birth related to exercise
Fetal Distress: RCT
Fetal bradycardia occurred in Olympic level athletes training at 90% of their max heart rate, 0 % at recommended moderate exercise level
SGA and LGA (small and large for gestational age): RCT, 79,692 pregnancies
SGA: (hazard ratio) (0.87; 95%. CI0.83-0.92)
LGA: (hazard ratio) (0.93; 95 % CI0.89-0.98)
27% decline in LGA babies in correlation to exercise
Limitations: none. Proved that exercise does not induce miscarriage
(Kuhrt et al., 2015)
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Level ii statistics continued
Study 2:
Level 1 evidence in a level 2 study: 4145 women in 12 RCT’s determined that reducing weight gain in pregnancy showed positive associations;
Reduction of weight gain at –0.61 (95% CI –1.17, –0.06) was illustrated when compared to the control group that involved physical activity.
Level 1 evidence in a level 2 study: 5 RCT’s with 115 women
Women who exercised before and during their pregnancy had a reduction in their risk for developing Gestational Diabetes by 55% and 24% (pooled OR 0.76, 95% CI 0.70-0.83; P<0.001) 11 Limitations There were many limitations to this searched topic: Cochrane database: few trials associated with this topic 2 out of 196 searched articles on MEDLINE supported risk of miscarriage as it relates to exercise. However, the articles were outdated and in a level 4-5 evidence rating system. The data was not reliable. No exact research was conducted to determine the risks of exercising in pregnancy as it relates to miscarriage. With foreground and background information, I was able to conclude the risks are minimal as it relates to miscarrying while exercising, yet no solid evidence was developed. conclusion Current information is key in determining the clinical significance of exercise in pregnancy, as it relates to miscarriage In the past, women were put on bedrest to prevent miscarriages, however, not only is that not the case, but women are now encouraged to exercise (Aleman et al., 2005). Moderate exercise on 3 or more days a week is recommended for a healthy pregnancy (Padmapriva et al., 2016). There is no correlation between moderate exercise and an increased risk for miscarriage in the first trimester (Kuhrt et al., 2015). 13 References Aleman, A., Althabe, F., Belizán, J. M., & Bergel, E. (2005). Bed rest during pregnancy for preventing miscarriage. Cochrane Database of Systematic Reviews, 2, 1-3. doi:10.1002/14651858.CD003576.pub2 Feodor Nilsson, S., Andersen, P., Strandberg-Larsen, K., & Nybo Andersen, A. (2014). Risk factors for miscarriage from a preventation perspective: A nationwide follow-up study. BJOG: An International Journal of Obstetrics and Gynaecology, 121(11), 1375-1385. doi:10.1111/1471-0528.12694 Kader, M., & Naim- Schuchana, S. (2014). Physical activity and exercise during pregnancy. European Journal of Physiotherapy, 16(1), 2-9. doi:10.3109/21679169.2013.861509 Kuhrt, K., Hezelgrave, N. L., & Shennan, A. H. (2015). Exercise in pregnancy. Obstetrician & Gynaecologist, 17(4), 281-287. doi:10.1111/tog.12228 References continued Li, L., Dou, L., Leung, P., Chung, T., & Wang, C. (2016). Chinese herbal medicines for unexplained recurrent miscarriage. Cochrane Database of Systematic Reviews, 1, 1-4. doi: 10.1002/14651858.CD010568.pub2 Melnyk, B. M., & Fineout-Overholt, E. (2015). Evidence-based practice in nursing & healthcare: A guide to best practice (3rd ed). Philadelphia, PA: Wolters Kluwer Health. Padmapriva, N., Shen, L., Soh, S., Shen, Z., Kwek, K., Godfrey, K., & … Müller- Riemenschneider, F. (2015). Physical activity and sedentary behavior patterns before and during pregnancy in a multi-ethic sample of Asian women in Singapore. Maternal & Child Health Journal, 19(11), 2523-2535. doi:10.1007/s10995-015-1773-3