This study has reported a 50.5% prevalence of cervical infection caused by high-risk oncogenic HPV among its 303 pregnant adolescents. In the literature, the prevalence of oncogenic HPV among pregnant women ranges from 5.8% to 51.7% [25,29]. On the other hand, the prevalence that was found seems not to differ from the observed rate at the same clinic ten years previously, that of 51.7%, in a study with 60 pregnant adolescents . Nevertheless, in the medical literature, the frequency of high-risk HPV on the cervix among adult women tends to be lower than that found among the adolescents in the present study [10,12,15,20,21,26,29–39].
Such a high prevalence of oncogenic HPV among pregnant adolescents prompts us to ponder the risk of not having them undergo a Pap smear as most recently recommended by the Brazilian Ministry of Health. The present policy is to limit the Pap smear to women aged 25 years or older in accordance with a few international protocols. The present study presents rates of colpocytological changes of 17.5%, with 10% of intraepithelial lesions, which are higher than that reported in most of the most recent studies of the Brazilian population, whose frequencies vary between 2.56% and 10.23 % [40–44]. These are rates not to be overlooked.
Certainly, vaccination of preadolescents and adolescents against HPV is an important public health action, which should lead to lower rates of HPV-caused infection and cytopathological abnormalities in such patients. However, despite the fact that government vaccination in Brazil began in March 2014, our infection rates remain high when compared to previous data. In a study carried out with 152 pregnant adolescents in a town approximately 90 km from São Paulo, not only was low adherence to the vaccination program found (only 44%), but also a remarkable ignorance of the ways to avoid being infected by HPV (66% did not know how HPV was transmitted) .
Furthermore, the detection of LSIL in the oncotic colpocytology of pregnant adolescents was strongly associated with the presence of oncogenic HPV (p< 0.001, OR= 9.23, CI 95%= 2.80-30.39) and of ASC-US (p= 0.004, OR = 5.31, CI 95%= 1.71-16.54). This result is in consonance with the current literature [1,4,8,9].
A tendency was observed toward an association between a diagnosis of HSIL and the occurrence of high-risk cervical HPV (p= 0.371, OR= 4.40, CI 95%= 0.17-113.1). No association was observed between the diagnosis of HSIL and the occurrence of high-risk cervical HPV (p = 0.371, OR = 4.40, 95% CI = 0.17-113.1). It was not statistically significant, though, most likely because there was only one case of HSIL among the 303 women assessed in the present study. As it is an infrequent event, a much larger cohort would be necessary to show a statistical connection between oncogenic HPV-caused infection and the presence of HSIL. As a matter of fact, such a link has already been well established in the literature.
Evaluation of the risk factors associated with an infection caused by oncogenic HPV revealed that less schooling, measured as fewer years of study, turned out to be an independent risk factor for the disease in pregnant adolescents. There is similar evidence in the literature [11,15].
A large number of partners in an adolescent’s lifetime was also identified as a predictor of oncogenic HPV-caused cervical infection. There is evidence in the literature to corroborate this finding [11,16,17,36,37,39].
The practice of a religion stood out as well as an independent risk factor for high-risk cervical HPV. There are no similar reports in the literature. This finding may be linked to the fact that women with religious beliefs show a behavioral pattern which differs from that of women with no such beliefs. However, one would imagine, at least in theory, that religion would encourage healthy behaviors and self-care, an expectation that runs counter to the findings of this research.
One might say that adolescents with religious beliefs are at a greater disadvantage in terms of socioeconomic status. But this was not the case. These girls had a higher mean of school years (p=0.009, 9.20 vs. 8.55 years) and higher rates of a family income, which was over two minimum salaries (p = 0.045, OR = 2.27, CI 95%= 1.06-4.84). On the other hand, they showed a great tendency toward abnormal vaginal secretion, which was greenish, yellowish, or grayish, as revealed by a speculum exam (p=0.085, OR=3.88, CI 95%=0.89-16.94), when compared to the girls without religious beliefs. There was also no statistically significant difference between the group of adolescents with some religious belief and the group without any religious belief regarding the presence of abnormal vaginal discharge (greenish or yellowish or grayish) in the specular examination performed during the prenatal consultation (p=0.085, OR=3.88, CI 95%=0.89-16.94). Besides, most of the adolescents who declared a belief in religion denied they actually practiced it (141/244=57.78%), which could signify an attitude of passivity, along with disinterest in or indifference to life. These findings, therefore, add to the uncertainty about the factors which could explain the association between religious beliefs and oncogenic HPV-caused infection. Additional qualitative studies might provide a better assessment of the reasons for such a connection.
Additionally, being a single pregnant woman without a steady partner was also a risk factor in univariate analysis (p = 0.018, OR = 2.15, CI = 1.14-4.06); however, this was not confirmed by the multivariate analysis (p = 0.141, OR = 1.651, CI = 0.846-3.222). There is similar evidence in the literature [10,13,33,36,37]. This outcome may have resulted from the fact that patients without a stable relationship tend to have a pattern of sexual activity which is different from that which has been observed in adolescents with a steady partner.
None of the obstetric outcome variables turned out to be statistically significant when groups were compared. There is similar evidence in the literature . However, other studies demonstrate an association between cervical HPV infection and the occurrence of some adverse obstetric outcomes such as: premature birth, preterm premature rupture of membranes, intrauterine growth restriction, low birth weight and fetal death [47–49]. Nonetheless, the high-risk HPV-infected pregnant adolescents showed a tendency toward delivering lower-weight newborns (p=0.243) and paying a smaller number of prenatal care visits (p=0.205).
Since this was a hospital-based study, the study sample may not correspond exactly with the general community. Another point which may be considered a limitation is the fact that the hospital where this study was carried out assists primarily women of low socioeconomic status, thus preventing the results from being generalized to the overall population.
However, our findings uphold the relevance of the theme, indicating the need for further longitudinal studies in our environment as a means of establishing better public health policies for this specific population.