DISCUSSION
deaths, anxiety
PRETERM BIRTH, PRETERM BIRTH, UTERINE CERVIX, FETAL DEATHS, PRETERM DELIVERY
The analysis estimated that implementing a screening program with TVUS in the second trimester of pregnancy to identify pregnant women with a cervix measure ≤ 25 mm, followed by prophylactic treatment with vaginal progesterone up to 36 weeks of gestation, costs less than the average of a SPB below 34 weeks. Considering the effectiveness of progesterone previously reported in the literature, its ideal use and the existence of an existing infrastructure for screening, the universal screening strategy for the prevention of preterm birth represents a saving of R$ 2,165.18 for each preterm birth avoided in a short-term projection, in which only the first 10 weeks after the probable date of delivery were considered.Previous studies have advocated universal screening considering the positive economic repercussions Our study used the prevalence of cervix ≤ 25 mm of a large sample of Brazilian pregnant women from different regions of the country. Preterm births used as a reference for the average cost of preterm birth were followed during the valuation period, providing complete data regarding the costs involved in the analyzed time horizon. However, as a limitation, this study did not consider in the analysis the costs prior to performing the ultrasound examination, such as the costs related to the ultrasound device, clinic, and physical infrastructure.In this regard, we consider that it would be possible to use the same device reserved for routine obstetric ultrasound and the same probe used during the obstetric ultrasound of the first trimester, not significantly burdening the costs related to equipment and infrastructure in centers that already perform routine prenatal ultrasound exams. The examination can and should be performed at the same time when the pregnant woman seeks the health care unit for obstetric or morphological GUS in the second trimester and by the same professional, considering an increase of 5–10 minutes in the examination time. Information from the National Health Survey (PNS) carried out in Brazil in 2013 with women from all over the national territory showed that 99.7% of the women interviewed had undergone some ultrasound during pregnancy, which makes it clear that this prenatal examination is already incorporated into the health care culture of the Brazilian population and that it has easy access However, implementation of the screening program would require trained professionals to perform cervical measurement. This control in the quality of the exam provided is feasible, since the technique for measuring the cervix is simple, with a learning curve that requires little time. The training for this technique is available for free and online on the Fetal Medicine Foundation platform, with evaluation and audit of images at the end of the course; therefore, it is accessible to professionals without significant cost increase Notably, in order to estimate the cost of preterm delivery, we considered the costs related to the first 10 weeks after the probable date of delivery; additionally, the costs related to the five fetal deaths and two neonatal deaths of our sample were not added. We consider this a limitation of our study. A long-term analysis could provide even more impactful results as to the cost-benefit ratio of implementing the screening program.Our study also presents the limitation of not considering the costs associated with the follow-up of women identified as at risk of preterm birth. It is true that, after a short cervix is identified, each patient will form their perception of risk and this can lead to more anxiety, stress, prenatal consultations, and work-related losses. At the same time, building a good doctor-patient relationship—which should be the premise of all medical care and which does not add to the final cost—can provide the necessary clarifications and guidance to reduce this state of vulnerability and facilitate adherence to the proposed treatment Thus, we can consider this analysis as a preliminary cost study, a first step towards a more attentive look into the possibility of implementing TVUS for uterine cervix measurement in the second trimester as a screening program for preterm birth in Brazil. We understand that the decision to use the costs of preterm birth treatment according to the SUS table (underestimated in relation to the actual cost) and the values of short cervix treatment according to CMED/ANVISA (market prices, higher than the prices of a possible direct acquisition), ultimately overestimate the costs of prevention and underestimate the costs of treatment and, therefore, underestimate the reduction and costs with screening. Even with this consideration, we found a cost reduction favorable to screening.However, the development of more robust results will require cost-effectiveness analysis with the modeling of several other factors that directly influence the incremental cost result, such as the acceptability to undergoing the screening, the real adherence to the treatment offered, and the work-related losses of women at higher risk of preterm delivery, enabling the estimation of values more consistent with reality through sensitivity analyses.