PRETORIA, Dec 30 (Reuters) - Quinton de Kock has announced his retirement from test cricket, another blow to South Africa"s brittle top six batting line-up in the longest format of the game that has seen them lose a number of established internationals in the last few years. De Kock has cited a desire to spend more time with his family with the imminent birth of his first child. He played in the 113-run first test loss to India at Centurion Park that finished on Thursday, and was always set to sit out the next two fixtures in the series while on paternity leave. The 29-year-old will, however, be missing permanently for South Africa in tests, though he will remain available in white ball cricket. "This is not a decision that I have come to very easily," De Kock said in a statement. "I have taken a lot of time to think about what my future looks like and what needs to take priority in my life now that (my wife) Sasha and I are about to welcome our first child into this world and look to grow our family beyond that. "My family is everything to me and I want to have the time and space to be able to be with them during this new and exciting chapter of our lives. "I love test cricket and I love representing my country and all that it comes with. I’ve enjoyed the ups and the downs, the celebrations and even the disappointments, but now I’ve found something that I love even more." Wicketkeeper-batsman De Kock scored 3,300 runs at an average of 38.82 in tests with six centuries since he made his debut in 2014. He also took 221 catches and 11 stumpings. "This is not the end of my career as a Protea, I’m fully committed to white ball cricket and representing my country to the best of my ability for the foreseeable future," he said. South Africa have also lost Hashim Amla, AB de Villiers and Faf du Plessis to test retirement in the last three years, all mainstays of their top six.