Thomson (1995) in a pilot RCT compared spontaneous (n=15), and directed (n=17) pushers. Observations found that women do not instinctively take a deep breath during spontaneous pushing, or commence expulsive effort at commencement of a contraction. In fact, instinctively they incorporate open and closed-glottis pushing. Thomson concluded that it is important that midwives understand what is considered normal second stage behaviour and that they provide support and permit women to instinctively labour.