Evidence from a randomized controlled trials for screening pregnant women who do not have symptoms for infection with trichomoniasis and treating women who test positive for the infection have not consistently shown a reduced risk of preterm birth. Further studies are needed to verify this result and determine the best method of screening. In the US, screening of pregnant women without any symptoms is only recommended in those with HIV as trichomonas infection is associated with increased risk of transmitting HIV to the fetus.
For 95-97% of cases, infection is resolved after one dose of metronidazole. Studies suggest that 4-5% of trichomonas cases are resistant to metronidazole, which may account for some “repeat” cases. Without treatment, trichomoniasis can persist for months to years in women, and is thought to improve without treatment in men. Women living with HIV infection have better cure rates if treated for 7 days rather than with one dose.
Your sex partner(s) should be treated at the same time you are being treated. This increases the cure rate and reduces the possibility of further transmission or reinfection. Sexual intercourse should be avoided during treatment until symptoms are gone and until partners have been treated. It is best to avoid sex for 1 week after treatment with a single dose of metronidazole. Male partners may not have symptoms but still need treatment.