Prenatal Exercise and Long-term Benefits for Baby

I’ve learned long ago that exercise makes a huge difference in my energy and mood so it’s become a prioritized, daily habit. Throughout pregnancy, exercise became even more necessary since I found movement helped with the discomfort of my stretching/expanding tissues, was my outlet for stress, helped with calf cramps, and was crucial for maintaining good sleep.

However, some days the motivation just wasn’t there and I fell into ruts along the way. I was bummed about not being able to do some old favourites like HIITs, core exercises, and certain sports. I also felt discouraged at times with my noticeable decrease in strength, muscle recovery and stamina. I felt like a stranger in my body at times, and knowing how to (safely) navigate exercise during pregnancy required extra consideration…which takes effort! And let's not forget the extra challenge of maintaining exercise during Covid times.

With further reading I discovered that exercise can go beyond benefits for mom–to-be: it can impact the future health and birth outcomes of the baby. This really shouldn’t come as a surprise, but once knowing this, I was able to push through my low motivation days for baby. It also made me make more of an effort to explore available prenatal resources.

I’m not going to get into the different types of exercise. Personally, I enjoyed a variety and was lucky to be in my second trimester in the summer to enjoy all the outdoor activities. Work-outs included: online prenatal barre workouts, prenatal yoga, prenatal HIITs, long swims, bike rides, modified resistance training, body weight exercises, reformer pilates, and jogging – nothing crazy. Some days I just stuck to walking my dog at a brisk pace. Do what you enjoy!

The recommended guidelines suggest that low risk pregnant women should aim for 30min of moderate-intensity exercise daily or 150min per week. Pregnancy isn’t the time to set fitness records, but daily movement is important.

I’m writing this article to:

1. Encourage those pregnant to incorporate exercise not only for your health and well-being, but your baby’s health too.

2. Try and beak the societal stigma that pregnant woman shouldn’t exert themselves and need to rest* God forbid sweating! (I may be a little bitter still by the comments I received about exercising during pregnancy – there’s clearly still a big knowledge gap out there.)

*Note – there are medical reasons why exercise isn’t safe during pregnancy and this should be discussed with your family doctor, midwife, or OBGYN. Obviously, modifications are important and care needs to be taken on intensity, form and hydration. Over-exercise can be dangerous.

Benefits of Prenatal Exercise FOR BABY:

1. Baby’s Size

a. Maternal prenatal exercise reduces the risk of delivering a newborn of large gestational weight at term. This is likely due to decreasing risk of maternal gestational diabetes and keeping mom in healthy BMI range. Larger babies are at greater risk of medical intervention at birth (like C-sections and instrumental use), increased risk of injury during labour and prolonged labour times.

Moderate prenatal exercise did NOT result in newborns that were born small for their gestational age (old argument and concern for exercise during pregnancy)

Prenatal exercise in women with normal weight and no complications did not have increased rate of pre-term birth (another old argument.)

b. Long terms studies have also found that babies born to mothers who exercised during pregnancy had a reduced risk of developing obesity, cardiovascular disease, and diabetes later in life. How amazing is that?!

2. Heart Rate and Heart Rate Variability

a. Studies have found correlations between increased fetal heart rate variability and maternal exercise

Increased heart rate variability is a good thing – it’s been associated with greater cardiovascular fitness. It means the fetus’ autonomic nervous system is more likely to adapt to and tolerate stress. Some say this helps them cope better during labour, which is a form of stress on the baby.

3. Neurodevelopment: Comparing babies whose mothers exercised in pregnancy:

a. At 1 year: no significant difference in psychomotor or mental development

b. At 12-24 months of age: higher IQ, vocabulary score, and language development

c. At age 5: higher general intelligence and oral language skills

d. Age 6-18: better academic performance

In general, exercise has been found to improve uterine blood flow and placental circulation. It is thought that these are some of the key underlying mechanisms that contribute to the positive fetal outcomes listed above. More long-term research is needed before any firm conclusions can be made, but hopefully it inspires you to get moving for your health and the health of your baby!

When in doubt with what kind of exercise to do, keep it simple and try 20 air squats and going for a walk.

Resources to check out:

Youtube: BodyFit by Amy

Youtube: Larie Fit

Doyogawithme.com à Prenatal Series

Sweat Happy Wellness à Offers prenatal reformer pilates in Lindsay

The Yoga Loft à Offers prenatal yoga series

References:

Clapp JF 3rd, Simonian S, Lopez B, Appleby‐Wineberg S, Harcar‐Sevcik R. The one‐year morphometric and neurodevelopmental outcome of the offspring of women who continued to exercise regularly throughout pregnancy. Am J Obstet Gynecol 1998;178:594–9.

Jukic AM, Lawlor DA, Juhl M, Owe KM, Lewis B, Liu J, et al. Physical activity during pregnancy and language development in the offspring. Paediatr Perinat Epidemiol 2013;27:283–93.

Domingues MR, Matijasevich A, Barros AJ, Santos IS, Horta BL, Hallal PC. Physical activity during pregnancy and offspring neurodevelopment and IQ in the first 4 years of life. PLoS ONE 2014;9:e110050.

Polanska K, Muszynski P, Sobala W, Dziewirska E, Merecz‐Kot D, Hanke W. Maternal lifestyle during pregnancy and child psychomotor development – Polish Mother and Child Cohort study. Early Hum Dev 2015;91:317–25.

Clapp JF III. Morphometric and neurodevelopmental outcome at age five years of the offspring of women who continued to exercise regularly throughout pregnancy. J Pediatr 1996;129:856–63.

Esteban‐Cornejo I, Martinez‐Gomez D, Tejero‐Gonzalez CM, Izquierdo‐Gomez R, Carbonell‐Baeza A, Castro‐Pinero J, et al. Maternal physical activity before and during the prenatal period and the offspring's academic performance in youth. The UP&DOWN study. J Matern Fetal Neonatal Med 2016;29:1414–20

Vargas-Terrones M, Nagpal TS, Barakat R. Impact of exercise during pregnancy on gestational weight gain and birth weight: an overview. Brazilian journal of physical therapy. 2019 Mar 1;23(2):164-9.

Bauer I, Hartkopf J, Kullmann S, Schleger F, Hallschmid M, Pauluschke-Fröhlich J, Fritsche A, Preissl H. Spotlight on the fetus: how physical activity during pregnancy influences fetal health: a narrative review. BMJ open sport & exercise medicine. 2020 Mar 1;6(1):e000658.