Trichomonas vaginalis (TV) infections have been associated with poor reproductive outcomes such as low birth weight and premature birth.1 TV is a flagellate protozoan considered to be sexually transmittable and sometimes related to low socioeconomic levels.2 It has been associated with adverse pregnancy outcome, manifested by preterm rupture of membranes, preterm delivery, low-birth-weight infants,3,4 infertility,5 and cytological abnormalities of the cervix.5,6

TV can be difficult to diagnose due to its heterogeneous presentation and problems with diagnostic testing. Many diagnostic tests, especially wet preparations are imperfect, but new nucleic acid molecular amplification tests (NAAT) have been shown to be advantageous for diagnosing the infection.7,8

The prevalence of TV among pregnant women in Brazil is unknown. It appears to be subject to under diagnosis and misdiagnosis in clinical practice because the symptom complex can overlap with other causes of vaginitis. As well, conventional diagnostic tests are often not readily available. The goal of this study was to estimate the prevalence of TV and associated risk factors in parturient women aged 15–24 years attending Brazilian public maternity units.

These data are sub-sample analysis of a cross-sectional study conducted in 2009 among parturient women attending Brazilian public hospitals. Parturient women attending selected maternity units in five geographic macro-regions of Brazil from March to November 2009 were invited to take part in the study and have been previously tested for Chlamydia trachomatis and Neisseria gonorrhoeae.9 Previously frozen aliquots of urine specimens were tested by NAAT for TV (Gen-Probe-Hologic, San Diego, CA).7,8

Chi square and Fisher's exact tests were used to assess differences in proportions, and the Student t test and analysis of variance were used for testing differences between mean values. Independent risk factors for Trichomonas infection were assessed through multiple logistic regression, with 0.15 as the critical p-value for variable entry and 0.10 as the criterion for variable elimination.

This project was submitted to and approved by the Research Ethics Committee of the Health Sciences Centre of the Federal University of Espírito Santo (Committee approval number 112/07) and to the ethical committee of each maternity unit taking part in the study.

A total of 299 women were included in this study. The prevalence rate of TV infection was 7.7% (95% CI: 4.7–10.7%). Mean age was 20.6 (SD=3.7) years and mean education age was 8.3 (SD=2.1) years of schooling.

Table 1 describes Trichomonas infection prevalence rate by demographic, behavioral and clinic characteristics. Parturient women with a positive Trichomonas test result reported illicit drug use more frequently (30.0% vs. 5.2%, p=0.001), reported more prior history of STI (21.7% vs. 6.5%, p=0.006) and attended less frequently antenatal visits (6.6% vs. 17.4%, p=0.001) when compared to the women without Trichomonas infection. Attending to six or more antenatal care appointments were significantly less among women with Trichomonas infection (4.1% vs. 12.6%, p=0.006).

The factors associated with Trichomonas in the multivariate logistic regression analysis were use of illicit drugs [OR=4.70 (95% CI: 1.63–13.56, p=0.004)] and not attending antenatal care [OR=5.15 (95% CI: 1.15–23.25, p=0.032)].

The prevalence rate of TV among young parturient women in Brazil was 7.7%, showing how frequent TV infection is in this population and the importance of routine monitoring and follow-up of pregnant women. This result was higher than the previously described in a study conducted in Northeast Brazil (4.1%).10

Given the high prevalence of TV infection relative to other STIs in various populations of women and its association with reproductive tract sequelae, including pelvic inflammatory disease and adverse outcomes of pregnancy,1,3,11 TV infection should be included in screening and control programs among pregnant women. Besides its importance in pregnancy, untreated TV infections have been shown to persist for at least three months in a longitudinal study, during which time adverse reproductive health outcomes could occur.12 Of notable importance also, since TV infection has been statistically associated to both transmission and acquisition of HIV in numerous studies, detection and treatment of TV infections can be an important component of HIV prevention programs.13

A limitation to our study is that it is cross-sectional rather than prospective and it used a sub-sample of the population. However, although a cross-sectional study is not the best study for determining risk factors, its application may be justified for assessing the prevalence and the associated factors for TV infection among pregnant women. This study was intended to generate some informative data among young pregnant women, in order to demonstrate the susceptibility of this group of women to the complications of TV infections.

The conditions of services providing care to maternal and child healthcare programs are factors that contribute to the health conditions of the population. These data demonstrate that it is important to discuss how to include routine screening for TV infection during antenatal care in Brazil.

The authors declare no conflicts of interest.