Within our section on women and thermography, the applications in pregnancy are especially noteworthy. It is known that many women want to go on training during their pregnancy (Kardel & Kase., 1998), but they may be worried if there were side effects. The large number of anatomical, biological, and psychological changes that occur in women during pregnancy makes it difficult to reach a consensus on the volume, intensity, and kind of exercise to be prescribed during pregnancy (Sillero-Quintana et al. 2012).
In any case, the American College of Sports Medicine (ACSM, 2020) recommends physical activity to pregnant women. At least 150 minutes of moderate activity each week, a minimum of 3 days per week, combining aerobic, resistance, and pelvic floor exercises, along with yoga and gentle stretching. Each program should be individualized based on situation, experience and current health status.
Melzer et al. (2010) showed that regular physical activity has benefits in mothers, such as improvement in cardiovascular functions, limited pregnancy weight gain, decreased musculoskeletal discomfort, reduced incidence of muscle cramps and lower limb oedema, mood stability, attenuation of gestational diabetes mellitus and gestational hypertension. While in the fetus, we see decreased fat mass, improved stress tolerance, and advanced neurobehavioural maturation.
Some of the regions that suffer from thermal changes during pregnancy are the hands and the womb. A higher skin temperature has been seen in the hands compared to the proximal forearms, even in the early stage of pregnancy (Beinder et al.1990). Goodlin & Brooks (1987) showed that the periumbilical areas are the warmest, as well as the inguinal areas, in pregnant women. Subsequently, Topalidou A., & Downe S., (2016) found that in the belly region, the coldest area was in the lower abdomen and confirmed that the hottest seems to be in the navel, as can be seen in Figure 1.
Figure 1. The image shows the lowest temperature in the rectus abdominis and the hot spot in the umbilicus.
But, we also have to take into account the risk of it, and because of that Sillero-Quintana et al. (2012) used thermography to investigate the effect of two types of exercise on the skin temperature of pregnant women: yoga and swimming.
Infrared thermography allows to measure and display accurate temperatures on the human skin without any contact, remotely and securely. It has been proposed as a monitoring tool during pregnancy, due to its great applicability to keep the conditions of both the mother and the fetus stable. As mentioned before, Sillero-Quintana et al. (2012), studied the effect in 28 volunteer pregnant women of two different organized physical activities on the skin temperature, yoga and swimming. They found heterogeneous results with an increase in Tsk in the whole body while practicing yoga during pregnancy. On the other hand, after an aquatic activity, the results were homogeneous compared to yoga, with a decrease in Tsk, even in the breast and belly areas, that could be related to the water temperature. Anyway, both activities were completely harmless to the fetus. In figure 2, we can see an example of how thermography was used to assess the mothers’ skin temperature.
Figure 2. Location of the ROI in each thermogram.
To sum up, exercise during pregnancy is beneficial for both mothers’ and babies’ health. Pregnant women undergo changes in skin temperature during and after exercise. These changes can be related to the normal anatomical, physiological and biological modifications because of the pregnancy. Thermography has been shown as a useful tool to monitor them in a non-invasive way, by measuring the temperature of the skin. Anyway, any of these changes is dangerous for pregnant women if the recommendations of intensity, duration and frequency of the exercise are respected.
American College of Sports Medicine. (2020). Pregnancy Physical Activity: Patricia Bauer [Brochure]. https://www.acsm.org/docs/default-source/files-for-resource-library/pregnancy-physical-activity.pdf?sfvrsn=12a73853_4
Beinder, E., Huch, A., & Huch, R. (1990). Peripheral skin temperature and microcirculatory reactivity during pregnancy. A study with thermography.
Goodlin, R. C., & Brooks, P. G. (1987). Abdominal wall hot spots in pregnant women. The Journal of reproductive medicine, 32(3), 177-180.
Kardel, K. R., & Kase, T. (1998). Training in pregnant women: effects on fetal development and birth. American journal of obstetrics and gynecology, 178(2), 280-286.
Melzer, K., Schutz, Y., Boulvain, M., & Kayser, B. (2010). Physical activity and pregnancy. Sports Medicine, 40(6), 493-507.
Sillero-Quintana, M., Conde-Pascual, E., Gomez-Carmona, P. M., Fernandez-Cuevas, I., & García-Pastor, T. (2012). Effect of yoga and swimming on body temperature of pregnant women. Thermology International, 22(3), 108.