A deaf couple have criticised a hospital for failing to provide them with a sign language interpreter during the traumatic birth of their son, which they say left them uninformed and added to the ordeal.

Hulusi Bati, 32, and Nadia Hassan, 28, claim the lack of communication, both during the birth and Hassan's 10-day stay at University College hospital, London, post-birth, amounted to discrimination, as they were not given the information that a hearing patient would have received. The British Deaf Association (BDA) said the case reflects the experience of many deaf people within the NHS, two out of three of whom have asked for an interpreter at a hospital appointment and not got one, according to a 2012 survey.

The couple from Camden, north London, first went to hospital on 7 December when Hassan was experiencing stomach pains. There was no interpreter available, forcing them to rely on Bati's 12-year-old daughter to interpret sensitive conversations.

When they returned the next day, a British Sign Language interpreter had been booked but left before 8pm and Hassan went into labour shortly before 9.30pm. There were complications and their son was eventually helped out with forceps.

"There was a lot of panic and they brought in my wife's sister-in-law to interpret but she's not an interpreter at all," said Bati. "She only knows the basics so there was no accurate medical information. I felt completely at a loss. I wasn't part of it. After the birth they took the baby away straight away and started putting injections in his foot. I wanted to hold my baby but the doctor said no. When I followed him and asked if the baby was OK he just gave me the thumbs-up sign." He said that the details of injections given to his wife and son were not communicated.

Hassan remained in hospital until 16 December. For the vast majority of the time, including doctor's rounds and breastfeeding instruction, no interpreter was provided, Bati said. "During breastfeeding, the midwife was trying to move my wife's head around," he said. "The midwife was basically manhandling my wife. I kept asking where's the interpreter and they said they kept saying 'he's coming' but he never came."

Bati said staff lacked awareness, making little effort to speak slowly to facilitate lip reading and sometimes poking them to get their attention in a manner he deemed rude. He said the midwives' manager had apologised for the couple's experience but it was not enough.

"I'd like them to provide a 24-hour service for access to interpreters," he said. "For example, if there was an emergency how would they communicate with them? People must be able to access the health services on a par with hearing people." He said he is taking legal advice. The Equality Act 2010 says that if someone is at a substantial disadvantage of accessing services because of a disability, reasonable adjustments must be made to allow access.

A spokesman for UCLH foundation trust said it aimed to provide the most comprehensive support possible to patients who need BSL interpreting services and works with a service provider to supply face-to-face interpreters but that this is not always possible in emergency or obstetric cases that arise at short notice.

He added: "Despite every effort, our partner had limited availability and was unable to meet all of our requests for an interpreter on this occasion. However, they were able to provide some interpreting services regularly during the couple's stay."

He said that the couple's complaint was being investigated as part of a formal complaints service but the hospital had already taken steps to complement its existing face-to-face interpreting service with a 24-hour electronic interpreting service.

Last year, a number of organisations launched the Our Health in Your Hands campaign, which asserts that deaf people have a right under equalities legislation to an interpreter in healthcare settings.

Paul Redfern, business development manager at the BDA and its representative on the campaign, said: "It's very worrying that, in this day and age when so many of us take access for granted, there is still a minority community in this country that's struggling to get the full information about their own health.

"Lack of proper access provision leads to misdiagnosis, delays in appointments and wrongly prescribed medication, and all of this is an extra burden on the NHS in terms of real costs so it would make a lot more sense if we had good access provision."