An Iranian judge has charged two women with the crimes of apostasy and propagating the Christian faith.
Maryam Rustampoor and Marzieh Amirizadeh could be sentenced to life in prison if they are convicted of the charges.
The women have been imprisoned for more than six months and are said to be in poor health.
In a court appearance last August the pair refused to recant their Christian faith before the court.
International Christian Concern (ICC), a human rights group, says the women have endured solitary confinement and been deprived of medical treatment while in prison.
An ICC spokesperson has requested that Christians all over the world "continue to pray for the release of the two converts and also for the improvement of their health."