Vaginal Electrical Impedance Detects the Fertile Window in Healthy Women: a Pilot Study
Keywords:Electrical Impedance, cervical mucus, ovulation, luteinizing hormone
This work analyzes the electrical impedance (EI) measurement of cervical mucus (CM) using a device to determine the fertile window. In this prospective and longitudinal study, fourteen healthy women aged 18 to 44 were enrolled to evaluate three menstrual cycles. EI was measured through a medical device inserted into the vagina for two minutes daily. Patients were monitored by urine luteinizing hormone (LH) strip, blood collection, and vaginal ultrasound to visualize the dominant follicle. Finally, the predictive EI capacity was validated by the receiver operating characteristic (ROC) of anovulatory vs. ovulatory impedances. The peak of LH was 35.7 (±4.5) mUI/ml and the dominant follicle size was 15.45 mm (±0.559). There were statistical differences in EI measurements between the follicular and luteal phases vs. the ovulation phase (p<0.0361 and p<0.0160). After data normalization, an area under the ROC curve (AUC) of 0.713 (P value= 0.0253), a Youden J index of 0.4545Ω, a sensitivity of 63.6%, and a specificity of 81.8% were found. Low EI in the ovulatory period belongs to the LH ovulatory peak and follicular release. EI can be used for ovulation monitoring, birth control, or promoting pregnancy as a safe and innocuous method.
Curlin M, Bursac D. Cervical mucus from biochemical structure to clinical implications. Front Biosci (Schol Ed) [Internet]. 2013;5(2):507–515. Available from: https://doi.org/10.2741/S386
Daunter B, Counsilman C. Cervical mucus: Its structure and possible biological functions. Europ J Obstet Gynecol Reprod Biol [Internet]. 1980;10(3):141-161. Available from: https://doi.org/10.1016/0028-2243(80)90056-8
Nicosia SV. Physiology of Cervical Mucus Productionle. Semin Reprod Med [Internet]. 1986;4(4):313–321. Available from: https://www.thieme-connect.de/products/ejournals/abstract/10.1055/s-2007-1022511
Dubey V, Mythirayee S, Tiwari RK, Gaharwar U, et al. Cervical Mucus Helps in the Fertilization. World J Pharm Pharm Sci [Internet]. 2016;5(10):242-250 Avalaible from: https://www.researchgate.net/publication/316681786_CERVICAL_MUCUS_HELPS_IN_THE_FERTILIZATION
Nakano FY, Leão R de BF, Esteves SC. Insights into the role of cervical mucus and vaginal pH in unexplained infertility. MedicalExpress [Internet]. 2015;2(2): 1-8. Available from: https://www.scielo.br/j/medical/a/qjRg5mV765Dvs5tYjCtBwyC/?format=pdf&lang=en
Fehring RJ. Accuracy of the peak day of cervical mucus as a biological marker of fertility. Contraception [Internet]. 2002;66(4):231–235. Available from: https://doi.org/10.1016/S0010-7824(02)00355-4
Murcia-Lora JM, Esparza-Encina ML. The Fertile Window and Biomarkers: A Review and Analysis of Normal Ovulation Cycles. Pers Bioet [Internet]. 2011;15(2):149-165. Available from: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0123-31222011000200004&lng=en.
Abbara A, Vuong LN, Ho VNA, Clarke SA, et al. Follicle Size on Day of Trigger Most Likely to Yield a Mature Oocyte. Front Endocrinol [Internet]. 2018;9:193. Available from: https://doi.org/10.3389/fendo.2018.00193
Randviir EP, Banks CE. Electrochemical impedance spectroscopy: An overview of bioanalytical applications. Anal Methods [Internet]. 2013;5:1098-1115. Available from: https://doi.org/10.1039/C3AY26476A
Řezáč P. Potential applications of electrical impedance techniques in female mammalian reproduction. Theriogenology [Internet]. 2008;70(1):1-14. Available from: https://doi.org/10.1016/j.theriogenology.2008.03.001
Walker DC, Brown BH, Smallwood RH,Hose DR, et al. Modelled current distribution in cervical squamous tissue. Physiol Meas [Internet]. 2002;23(1):159. Available from: https://doi.org/10.1088/0967-3334/23/1/315
Albrecht BH, Fernando RS, Regas J, Betz G, et al. A new method for predicting and confirming ovulation. Fertil Steril [Internet]. 1985;44(2):200-205. Available from: https://doi.org/10.1016/S0015-0282(16)48736-4
Moreno JE, Khan-Dawood FS, Goldzieher JW. Natural family planning: Suitability of the CUETM method for defining the time of ovulation. Contraception [Internet]. 1997;55(4):233-237. Available from: https://doi.org/10.1016/S0010-7824(97)00007-3
Moreno JE, Weitzman GA, Doody MC, Gibbons WE, et al. Temporal relation of ovulation to salivary and vaginal electrical resistance patterns: Implications for natural family planning. Contraception [Internet]. 1988;38(4):407-418. Available from: https://doi.org/10.1016/0010-7824(88)90082-0
Brown BH, Milnes P, Abdul S, Tidy JA. Detection of cervical intraepithelial neoplasia using impedance spectroscopy: A prospective study. BJOG [Internet]. 2005;112(6):802-806. Available from: https://doi.org/10.1111/j.1471-0528.2004.00530.x
Brown BH, Tidy JA, Boston K, Blackett A, et al. Relation between tissue structure and imposed electrical current flow in cervical neoplasia. Lancet [Internet]. 2000;355(9207):892-895. Available from: https://doi.org/10.1016/S0140-6736(99)09095-9
Gandhi SV, Walker DC, Brown BH, Anumba DO. Comparison of human uterine cervical electrical impedance measurements derived using two tetrapolar probes of different sizes. Biomed Eng Online [Internet]. 2006;5:62. Available from: https://doi.org/10.1186/1475-925X-5-62
Gandhi SV, Walker D, Milnes P, Mukherjee S, et al. Electrical impedance spectroscopy of the cervix in non-pregnant and pregnant women. Eur J Obstet Gynecol Reprod Biol [Internet]. 2006;129(2):145-149. Available from: https://doi.org/10.1016/j.ejogrb.2005.12.029
Jokhi RP, Ghule VV, Brown BH, Anumba DO. Reproducibility and repeatability of measuring the electrical impedance of the pregnant human cervix-the effect of probe size and applied pressure. Biomed Eng Online [Internet]. 2009;8:10. Available from: https://doi.org/10.1186/1475-925X-8-10
Saito TK de S, Pedriali RA, Gabella CM, Chaves Junior M, et al. Preliminary results of cervical impedance measurements. Res Biomed Eng [Internet]. 2018;34(02):110-114. Avalaible from: https://doi.org/10.1590/2446-4740.05617
Timing of ovulation based on vaginal pH by Gorodeski GI, Liu CC. (2008, Mar. 20). Patent 11/574279 [Internet]. Available from: https://uspto.report/patent/app/20080071190
Freundl G, Bremme M, Frank-Herrmann P, Godehardt E, et al. The CUE fertility monitor compared to ultrasound and LH peak measurements for fertile time ovulation detection. Adv Contracept [Internet]. 1996;12:111-121. Available from: https://doi.org/10.1007/BF01849632
Vigil P, Cortés ME, Carrera B, Hauyón R, et al. El moco cervical en la fisiología reproductiva. In: Guzmán E, Croxatto H, Lalonde A (eds). Cervical Mucus in Human Reproduction. Copenhague:Scriptor; 2014. 325-334p.
Faes TJC, van der Meij HA, de Munck JC, Heethaar RM. The electric resistivity of human tissues (100 Hz–10 MHz): a meta-analysis of review studies. Physiol Meas [Internet]. 1999;20:R1. Available from: https-://doi.org/10.1088/0967-3334/20/4/201
Gould KG, Ansari AH. Electrolyte interactions in cervical mucus and their relationship to circulating hormone levels. Contraception. 1981; Available from: https://doi.org/10.1016/0010-7824(81)90078-0
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