Abstract

Background

Vaginitis due to Trichomonas vaginalis is one of the most common of sexually transmitted diseases. Trichomoniasis affects women during pregnancy as well but it is not clearly established whether it causes preterm birth and other pregnancy complications.

Objectives

The objective of this review was to assess the effects of various treatments for trichomoniasis during pregnancy.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 January 2011).

Selection criteria

Randomized trials comparing anti‐trichomonas agents during pregnancy. Trials including symptomatic or asymptomatic women with trichomoniasis were eligible.

Data collection and analysis

Two review authors assessed eligibility and trial quality.

Main results

We included two trials with 842 pregnant women. In both trials around 90% of women were cleared of trichomonas in the vagina after treatment. In the US trial, women with asymptomatic trichomoniasis between 16 and 23 weeks were treated with metronidazole on two occasions at least two weeks apart. The trial was stopped before reaching its target recruitment because metronidazole was not effective in reducing preterm birth and there was a likelihood of harm (risk ratio 1.78; 95% confidence interval 1.19 to 2.66). The South African trial recruited women later in pregnancy and did not have the design and power to address adverse clinical outcomes. We excluded two recent studies, identified for the current update, because they did not address the primary question.

Authors' conclusions

Metronidazole, given as a single dose, is likely to provide parasitological cure for trichomoniasis, but it is not known whether this treatment will have any effect on pregnancy outcomes. The cure rate could probably be higher if more partners used the treatment.

Author(s)

A Metin Gülmezoglu, Maimoona Azhar

Abstract

Plain language summary

Interventions for trichomoniasis in pregnancy

Metronidazole is effective against a trichomoniasis infection during pregnancy, but may increase the risk of preterm and low birthweight babies.

Trichomoniasis is a very common sexually transmitted infection. Symptoms include vaginal itching and discharge. It is not clear if pregnant women with trichomoniasis are more likely to give birth preterm, or have other pregnancy complications. The review of two trials, involving 842 women, found that the drug metronidazole is effective against trichomoniasis when taken by women and their partners during pregnancy, but it may harm the baby due to early birth. One of the trials was stopped early because women taking metronidazole were more likely to give birth preterm and have low birthweight babies. Further research into trichomoniasis treatments for pregnant women is needed.

Author(s)

A Metin Gülmezoglu, Maimoona Azhar

Reviewer's Conclusions

Authors' conclusions 

Implications for practice 

This review found no evidence to support the use of metronidazole in pregnant asymptomatic women with trichomonas vaginalis. It is not clear why metronidazole should cause adverse pregnancy outcomes when it is effective in clearing the infection. Given that Trichomonas vaginalis is a sexually transmitted infection with unpleasant symptoms and associated with adverse outcomes, including facilitating HIV transmission (Sorvillo 2001), it would seem prudent to treat symptomatic women during pregnancy.

Implications for research 

Metronidazole, or nitro‐imidazoles in general, are the first choice agents against Trichomonas vaginalis. There are no other readily available medications to replace this class of drugs for the treatment of trichomonas infections. Metronidazole when given in combination with other antibiotics did not show decline in the rate of preterm birth or low birthweight. There are two research questions that need to be answered:

• whether the treatment of pregnant women with symptoms (trichomonas vaginitis) is effective in reducing preterm birth;
• whether the adverse effect of increased preterm birth in treated asymptomatic women with trichomonas observed in one, prematurely stopped trial is real.

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