Background One of the main pregnancy complications in Peru is syphilis, a disease with severe complications that can be prevented trough early diagnosis and treatment. The objective of this study was to estimate the factors associated with syphilis infection among pregnant women in the district of Ventanilla – Peru in 2012.

Methods The Project WawaRed “Getting connected for a better maternal and child health” involved the implementation of an electronic health record (EHR) for maternal health, linked to SMS messages sent to pregnant women and tailored to their health profile and gestational age. A crossover study was performed using data collected via the EHR on 2012. Clinical and laboratory data from pregnant women attending one of 16 different health centres in Ventanilla were analysed. These included test results for a rapid syphilis test carried out in their first antenatal care visit.

Results A total of 4915 pregnant women were included. The mean of age and age at first intercourse were 26.0 (95% CI: 25.8–26.2) and 17.3 (95% CI: 17.2–17–4) respectively. The prevalence for syphilis was 1.4 (95% CI: 1.1–1.7) and for HIV was 3.0 (95% CI: 1.4–4.6). There were 2 patients co-infected with HIV and syphilis. The factors analysed were: age, level of education, marital status, number of pregnancies, history of abortion, age at first sexual intercourse and contraceptive methods used. This study showed that pregnant women who use a intrauterine device (PR:4.9, p = 0.02) as a contraceptive method as opposed to condom were at higher risk for syphilis, while older age at sexual debut was associated to a lower risk for syphilis (PR:0.88, p < 0.01).

Conclusion Delayed sexual debut and condom use are once again identified as forms of preventing STI, and should be important components of family planning programmes.