The Akathist Hymn was written in a time when the interest around Mary was focused closely on her pregnancy. This was in response to a number of controversies in the fourth and fifth centuries over when, precisely, the Son of God came to be.
Arius, a priest, began teaching around AD 320 that Christ existed before the universe, and that he created it and everything in it. However, he himself was created by God the Father. In other words, Christ had not always existed, from eternity. "There was a time when he was not", Arius said.
This, of course, aroused great controversy. In AD 325 Emperor Constantine called together the clergy for the first Ecumenical Council. They met in Nicea and after much debate produced the Nicene Creed, a statement of faith which was signed by all but three of the 318 bishops present. The creed states that Christ was not created by God. Rather, he is "begotten, not made" and "of one being with the Father." Arianism hung around as a heresy for centuries.
In the fifth century, Nestorius, Patriarch of Constantinople, began to teach that Christ had two separate natures: human and divine. He taught that it was wrong to say that 'God suffered' or 'God was crucified' because those events were only experienced by Christ's human nature, not his divine nature.
Likewise, the child Mary carried in her womb could not have been God, because "no one can bring forth a son older than herself". He opposed calling her Theotokos (though the title had been in use at that point for at least 200 years). Instead, he wished her to be titled Christotokos, indicating that she gave birth to Christ's human nature alone. The third Ecumenical Council, in Epehsus, AD 431 rejected Nestorius' argument. The son of Mary was both human and divine, and she properly deserved the title of Theotokos.
Theotokos is often translated 'Mother of God'. However, it more properly means 'Birthgiver of God'. While Mary is the only Theotokos, we can all hope to become Theophorus, or God-bearers. We desire and aim to carry God within us, through the Holy Spirit.
I know people who have problems with the title Theotokos because, well, how can Mary be the mother of God? How could she give birth to God? Is she a goddess? Is she older than a being that has no beginning and no end? No. Of course not. Stop being silly.
Mary did, quite literally, give birth to God in the only kind of birth He has ever experienced. The Son was born onto earth in a mortal, human form. He has two natures, both human and divine, but they are inextricably and permanently joined. You cannot have one without the other. If Mary gave birth to Christ's human nature here on earth, then she also gave human form, human birth to his divine nature. But that doesn't imply that she created the divine nature. Just that she, and only she as Christ had no human father, gave Him His mortal, human flesh.