Tehran carries out series of judicial reviews but lawyer fears women who have not attracted media attention will be executed

Iran appears to be quietly changing the sentences of Iranians awaiting death by stoning to hanging after international outcry following the case of Sakineh Mohammadi Ashtiani, a 43-year-old mother of two.

Mariam Ghorbanzadeh, 25, who was six months' pregnant and miscarried after being beaten up in Tabriz prison this week, was initially sentenced to death by stoning for adultery but her sentence has been commuted to hanging in a rapid judicial review. The decision is thought to have been driven by the Iranian authorities' desire to avoid further international condemnation over the barbaric punishment.

According to Iranian law, officials could not carry out her sentence while she was pregnant. Speaking to the Guardian, her lawyer, Houtan Kian, who represents Mohammadi Ashtiani and two other women kept in Tabriz prison convicted of adultery, said: "My fear is that Iran executes Mariam and those others whose cases have not attracted media attention."

Another of Kian's clients, Azar Bagheri, 19, was imprisoned at the age of 15 after her husband accused her of having an extramarital relationship. Bagheri was on death row for adultery but her sentence was commuted to 100 lashes after Mohammadi Ashtiani's story came to light. Although Bagheri's death penalty was handed down four years ago, the sentence could not be carried out until she was 18 years of old.

"All these women are convicted for adultery but Iran is trying to change their sentences after Sakineh's case has embarrassed them," Kian said.

On Wednesday night, Iran put Mohammadi Ashtiani on a state-run TV programme, in which she appeared to confess to adultery and involvement in murder and said she would sue her first lawyer, Mohammad Mostafaei, who has fled Iran after succeeding in highlighting her case and bringing it to international attention. Mostafaei, who crossed the Iran-Turkey border illegally, was arrested in Turkey on immigration charges but was later released and taken to Norway after EU diplomats intervened. Norway has since offered him asylum.

Mohammadi Ashtiani's appearance on TV, with a blurred face, shaky voice and holding a piece of paper in her hand, prompted an immediate reaction from Kian, who condemned the televised "confession" and said she was tortured for two days before agreeing to give the interview. Amnesty International called it "a complete mockery of the judiciary system in Iran".

Kian dismissed Iran's accusations that Sakineh had murdered, or was an accomplice to the murder, of her husband. He said the murderer – who Iran's judiciary admitted four years ago had actually killed her husband – was freed when Sakineh's children pardoned him. The programme also showed two of her relatives saying that Sakineh was an accomplice to murder. Last week, in an interview with the Guardian through an intermediary, Mohammadi Ashtiani said she was convicted of adultery and was acquitted of murder.

Iran is believed to have frozen all executions until the end of the holy month of Ramadan. At least 12 Iranian women and three men are awaiting execution by stoning.

• This article was amended on 13 August 2010. The original said that a TV programme showed relatives saying that Sakineh was a murderer. This has been clarified.