# during pregnancy, the function of the cervix is to retain and protect the growing baby > The function of the cervix from this moment is to retain and protect the growing conceptus. An effective barrier is primarily accomplished through retaining a sufficient length of closed cervix within which the mucus plug can deter ascent of microbes from the lower genital tract [29]. This is aided by maintaining sufficient strength at the level of the internal os to discourage descent of the fetal membranes and conceptus down the cervical canal, which may shorten this barrier and/or dislodge the mucus plug.[[(Nott et al, 2016)#^ftxuj]]