Effects of transcutaneous electrical nerve stimulation on fetal and placental development in an experimental model of placental insufficiency

Abstract

Objective: To elucidate the effects of transcutaneous electrical nerve stimulation (TENS) in pregnancies with placental insufficiency.

Methods: Pregnant rats were subjected to uterine artery ligation and to TENS according to the following groups: ligated stimulated (LS); ligated non-stimulated (LN), control stimulated (CS); and control non-stimulated (CN). Fetal external measurements, such as crown–rump length (CRL), fronto-occipital distance (FOD), thoracic ventral-dorsal (TVDD) and abdominal ventral-dorsal (AVDD) distances were analyzed together with the area occupied by fetal internal organs. Glucose transporter 1 (GLUT-1) expression was evaluated by immunohistochemistry in fetal organs. Thickness of junctional, labyrinth and intermediate placental zones was analyzed by morphometric evaluation in HE-stained slides, and placental hypoxia-inducible factor 1 alfa expression was measured by real-time polymerase chain reaction.

Results: In LN and CS groups compared to the CN group, CRL was reduced (27.51/28.95 versus 30.16 mm), as well as FOD (6.63/6.63 versus 7.36 mm), AVDD (7.38/8.00 versus 8.61 mm) and TVDD (6.46/6.87 versus 7.23 mm). Brain GLUT-1 expression was higher in LS (1.3%) and CS (1.8%). The area occupied by placental vessels in the labyrinth zone (29.67 ± 3.51 versus 20.83 ± 7.63) and intermediate zone (26.46 ± 10.21 versus 10.86 ± 8.94) was larger in the LS group than in the LN group.

Conclusions: Our results suggest a negative effect of TENS on placental development, thus compromising the maintenance of adequate blood flow to the fetus.

• Hypoxia
• IUGR
• perfusion
• placenta
• pregnancy
• TENS

Declaration of interest

The authors report no declarations of interest.

This work was financially supported by: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq – National Counsel of Technological and Scientific Development), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES – Coordination for the Improvement of Higher Education Personnel Foundation), Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG – Research Foundation of the State of Minas Gerais) and Fundação de Ensino e Pesquisa de Uberaba (FUNEPU – Research Foundation of Uberaba).