Protests are underway in Dublin, Galway, Sligo, Killkenny and Carlow calling on the Government to legislate for the X Case.
Thousands of people are expected to attend the demonstrations which will coincide with candlelit vigils later this evening around the country in memory of Savita Halappananvar.
The 31-year-old dentist died of blood poisoning last month in University College Hospital Galway. She had suffered a miscarriage. Her husband Praveen said she was repeatedly refused a medical termination.
Sinead Redmond from the Irish Choice Network says today's demonstrations were about preventing the deaths of other women in these circumstances.
"I am certain it will happen again if legislation is not introduced," she said. "It's happened before."