Human body temperature average is 37 °C and that of a fetus is higher than the maternal temperature by 0.3 to 0.5 °C 2 (1). Heating above this temperature can alter the normal physiological process, causing, for example, changes in metabolic reactions or neuronal migration and even fetal cell death(2). Infectious processes trigger an imbalance in the homeostatic circuit, generating heating of the structures that support intrauterine life and physiological and immunological changes capable of putting the life of the fetus at risk during or after its birth(3). This study aimed to investigate the placental heating of parturient women who had their newborns by vaginal delivery or cesarean section, to verify if placental thermography can serve as a method of classifying the degree of fetal compromise.

This is a random observational report. Part of a randomized controlled study involving puerperal women, in which we sought to investigate the effectiveness of a photobiomodulation protocol to modulate the acute inflammatory process and the perception of pain in puerperal women who suffered perineal lacerations in the immediate normal postpartum period, admitted in a Maternity Hospital. The curiosity arose when observing a report of heating increase obtained by a two-finger touch procedure in admitted parturient women and in labor.
'The research was approved by the Ethics Committee for research with human beings and registered in the Brazilian Clinical Trials Registry.
Parturient women aged between 18 and 40 years, with and without reports of infectious diseases, with a clinical history of comorbidities and fetal malformation, literate, admitted to a normal delivery room and operating room were included. Fourteen postpartum women had their newborns by cesarean section, seven normally. Parturient women diagnosed with mental disorders were excluded.
After signing the Free Informed Consent Term, two images of the placenta were captured immediately after delivery by a commercial thermal camera. Both birth places at room temperature. One image from the placenta side closer to the fetus (fetal face) and one from placenta side closet to the uterus m wall (maternal face). Subsequently, the placenta images were analyzed with the Flir tools program and information of the maximum, minimum and average temperature values of the area of interest were extracted. Data were exported and analyzed in Python with the seaborn library. Histogram graphs were also made to verify the thermal distribution of the pixels.

Twenty-one parturient women were admitted to the survey, with a mean age of 26.7±6.2 years. Most were married and had completed high school and declared themselves as mixed race. Seven patients had placental heating with an average of the Maternal Face greater than 36 °C. Sixteen patients whose delivery was normal had a placental temperature mean of 37.9 ± 1.7 °C, while those who underwent cesarean sections had a mean of 35.4 ± 1.5 °C. Two parturient women were induced into labor and had a mean placental heating of the maternal face equal to 38.0± 1.2 °C, while the mean of those who were not labor-induced was 35.8 ± 1.8 °C. Figure 1 shows a graph of the image pixel distribution as a function of the temperature of placentas from normal delivery patients in relation to those who underwent cesarean section. The three patients who were infected with Treponema pallidum had a mean temperature of the placenta’s maternal face of 38.7± 1.6 °C, while the mean of those who did not have the infection was 35.5 ± 1.5 °C. Figure 2 shows two thermographic images of patient placentas, one without infection and the other with Treponema pallidum.

From the histograms It was possible to observe a clear trend of placental heating separation tendency between parturient women with normal delivery and cesarean section. Similar tendency seems to be present when comparing the thermography of the normal and the infected placenta.

A survey with a larger sample size needs is being implemented to confirm this finding.

Thomas Jansson, Teresa L. Powell. Placental role in fetal programming: underlying mechanisms and potential interventional approaches. Rev. clinic Sci, London. 2007.
Julienne N Rutherford, Suzette D. Tardif. Placental efficiency and intrauterine resource allocation strategies in common marmosets pregnancy. Rev. Am J Phys Anthropol. 2008
Keith M. Godfrey. The role of the placenta in fetal programming - a review. Rev. Placenta. 2002

Continence 2S2 (2022) 100299
DOI: 10.1016/j.cont.2022.100299