Vaginal yeast infection is a disease characterized by signs, symptoms of vaginitis, vaginitis and presence of fungi (mainly Candida). This is the second most common cause of vaginitis, and up to 75% of women of reproductive age have at least one vaginal yeast infection, [1,2] about 40-45% of patients will have the recurrent condition several times and 5-8% will develop recurrent vulvovaginal candidiasis (up to 10%) - defined as inflammation at least four times a year. [3,4]
Symptoms of vaginal yeast infection include: severe itching, painful urination and sexual intercourse, severe nausea (white cheese, no unpleasant odor except superinfection).
Mashburn J. Vaginal infections update. J Midwifery Womens Health 2012;57(6):629-34
das Neves J, Pinto E, Teixeira B, Dias G, Rocha P, Cunha T, et al. Local treatment of vulvovaginal candidosis: general and practical considerations. Drugs. 2008;68(13):1787-802
David W Denning, Matthew Kneale, Jack D Sobel, Riina Rautemaa-Richardson. Global burden of recurrent vulvovaginal candidiasis:a systematic review. Lancet Infect Dis 2018. Published Online August 2, 2018 http://dx.doi.org/10.1016/s1473-3099(18)30103-8
Candida albicans is the main causative agent of vaginal yeast infection, accounting for 80-92% of cases. The rest are other yeasts, mostly C. glabrata. These fungi are part of the vaginal microenvironment without causing symptoms in about 20% of healthy women. 
Classification of vaginal yeast infection: uncomplicated and complicated. Uncomplicated VYI occurs at a low frequency (<4 times per year), with mild to moderate symptoms, most likely caused by Candida albicans, and the infected women have a normal immune system. Complicated VYI is characterizd by one of the following: persistent inflammation (4 or more years), severe vaginitis, non-Candida albicans or co-morbidities such as diabetes mellitus, immunosupression, use of immunosuppressive drugs. 
Sobel JD. Gentital candidiasis. Medicine 2010;38(6):286-90
Center for Disease Control and Prevention. Vaginal Discharge-STD Treatment Guidelines. 2015
Vaginal yeast infections occur mainly in women of reproductive age, with epidemiological data showing that at age 25, about 50% of women had at least one vaginal yeast infection.  Vaginal yeast infections are very rare in preterm girls, with rates beginning to increase at age 20 and reach the peak in the 30 to 40 age group. The rate of vaginal yeast infections is linked to the amount of estrogen in the body, as increased estrogen levels increase glycogen levels in vaginal tissues, creating a carbon source for Candida. This explains why vaginal yeast infections mainly occur at reproductive age. [2-4]
Sobel JD, Faro S, Force R, et al. Vulvovaginal candidiasis: Epidemiologic, diagnostic and therapeutic considerations. Am J Obstet Gynecol 1998;178:203–211
Cotch MF, Hillier SL, Gibbs RS, Eschenbach DA. Epidemiology and outcomes associated with moderate to heavy candida colonization during pregnancy. Vaginal Infections and Prematurity Study Group. Am J Obstet Gynecol 1998; 178: 374–80.
Dennerstein GJ, Ellis DH. Oestrogen, glycogen and vaginal candidiasis. Aust N Z J Obstet Gynaecol 2001; 41: 326–28.
Tarry W, Fisher M, Shen S, Mawhinney M. Candida albicans: the estrogen target for vaginal colonization. J Surg Res 2005; 129: 278–82.
Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. Clotrimazole can be used during pregnancy, but only under the direction of a Health Care Professional.
During pregnancy the treatment should be carried out with clotrimazole vaginal tablets, since these can be inserted without using an applicator.
There are no data on the excretion of clotrimazole into human milk. However, systemic absorption is minimal after administration and is unlikely to lead to systemic effects. Clotrimazole may be used during lactation.
A combination of Canesten VT and cream may increase the effectiveness of the treatment.  Seek advice from a doctor or pharmacist prior to starting treatment.
A study by W. Mendling and R. Schelegelmilch compared the efficacy of suppository clotrimazole on treatment of vulvovaginal candidiasis with combination of suppository and cream formulation. The study was conducted on 160 women with Candida vaginitis, which spread to labia majora and labia minora. The results showed that the combination group was more effective in reducing the symptoms: erythema vulgaris, itching. The rate of complete healing according to the physician's assessment and the rate of mycotic cure by microbiological results in the combination group was also higher. 
Mendling W, Schlegelmilch R. Three-day combination treatment for vulvovaginal vandidosis with 200 mg clotrimazol vaginal suppositories and clotrimazol cream for the vulva is significantly better than treatment with vaginal suppositories alone–an earlier, multi-centre, placebo-controlled double blind study. Geburtshilfe Frauenheilkd. 2014;74:355-60.
In general, the efficacy and safety of two types of Canesten VT1 and VT6 in vaginal yeast infection treatment are similar.  There is currently no optimal regimen for the treatment of persistent VYI, but experts recommend the use of longer-term azole regimens than short-term regimens (1- 3 days) during the treatment phase. 
In terms of data, in the direct comparison study between two regimens using VT6 and VT1, the rate of mycotic cure after 1 week VT 1 was slightly higher (89.2% vs 87.5%) but after 4 weeks that of VT6 was slightly higher (84.5% vs 82.4%).  The authors of the study also pointed out that the long-term pattern of recurrence may be slightly higher in the VT1 group. Therefore, patients with recurrent vaginitis may benefit with VT6 regimen.
Loendersloot EW et al. American Journal of Obstetrics & Gynecology. 1985;152(7):953-955
The pathogenesis of vaginal yeast infection is associated with vaginal microflora imbalance, overgrowth of fungus, and invasion of fungal epithelial cells.  Therefore, it is not considered a sexually transmitted disease.
Sobel JD. Epidemiology and pathogenesis of recurrent vulvovaginal candidiasis. Am J Obstet Gynecol 1985; 152:924.
Sobel JD, Faro S, Force RW, et al. Vulvovaginal candidiasis: Epidemiologic, diagnostic, and therapeutic considerations. Am J Obstet Gynecol 1998; 178:203.
Merson-Davies LA, Odds FC, Malet R, et al. Quantification of Candida albicans morphology in vaginal smears. Eur J Obstet Gynecol Reprod Biol 1991; 42:49.
Vaginitis caused by Candidiasis usually develops usually at the end of the ovulation cycle (within about a week before the start of the new menstrual cycle). [1,2] Vaginal yeast infections occur at this stage possibly due to : a. the hormonal imbalance leading to reduced cell-mediated immune response. [1,2,3]
Kalo-Klein A, Witkin SS (1989). Candida albicans: cellular immune system interactions during different stages of the menstrual cycle. Journal of Obstetrics and Gynaecology 161 (5): 1132-1136
Salinas-Muñoz L, Campos-Fernández R, Mercader E, Olivera-Valle I, Fernández-Pacheco C, Matilla L, García-Bordas J, Brazil JC, Parkos CA, Asensio F, Muñoz-Fernández MA, Hidalgo A, Sánchez-Mateos P, Samaniego R and Relloso M (2018) Estrogen Receptor-Alpha (ESR1) Governs the Lower Female Reproductive Tract Vulnerability to Candida albicans. Front. Immunol. 9:1033. doi: 10.3389/fimmu.2018.01033