She was not allowed to breastfeed or at least to touch her child, her second, while it lived.
The fatal illness was diagnosed three months into her pregnancy.
She has told BBC Sinhala Service on condition of anonymity that only a mother would know the sufferings due to such children.
The woman said doctors told her that the existing laws on abortion did not allow her to end her pregnancy.
When she delivered under caesarean section, she too, became gravely ill, and she said that had something happened to her, the first-born, a four-and-a-half year old, would not have anyone left in the world.
Parents of children with birth defects face social as well as economic hardships.
Also, underage girls raped by a family member have to endure untold physical and mental sufferings.
In India, a 10-year-old was not allowed an abortion by courts after she was raped, and she delivered in August.
Similar instances are reported from Sri Lanka too.
According to clause 303 of the penal code, abortion is allowed only if there is a life-threatening situation for the mother from the foetus.
The Perinatal Society of Sri Lanka has proposed to the government to allow abortion to terminate pregnancy of a woman carrying a child with a fatal birth defect or in the case of a rape victim.
It could be established within the first 15 to 20 weeks of pregnancy if the child has a fatal illness.
Doctors say most are stillbirths in such cases, and the others die within the first seven days of birth.
Dr. Kapila Jayaratne of the Family Health Bureau says it is a burden both socially and economically to care for a woman carrying a child with a birth defect, and for the child itself if it lives for a brief period.
He notes that despite whatever religious beliefs are there, the women who undergo such situations should be considered humanely and allowed to take their own decision.
Dr. Jayaratne adds that safeguards could be taken to prevent the misuse of a relaxation of abortion laws.
Bureau reports say nearly 6,000 children with birth defects are born every year.
Of them, 200-250 die within the first seven days and 500-600 within the first year.
Birth defects are also blamed for 1,710 stillbirths per annum.
However, the Catholic Bishops Conference says it vehemently condemns legalizing abortion under any circumstances.
From the day of conceiving, the life begins, and the life is sacred, and no one has the right to destroy it, it said in a recent statement.
At the Vatican, Pope Francis last year gave the right to priests to pardon a woman who had undergone abortion.