**1. Introduction: Definitions - vaginal delivery**

Vaginal delivery is defined as a natural birth process which does not usually require significant medical intervention [1]. It is the birth of offspring in mammals or babies in humans, through the vagina, also known as the "birth canal". Improvement of normal vaginal delivery can be made through proper management of normal labour, guided by current knowledge [1]. Most women deliver vaginally although the percentage of operative deliveries has increased from 21 percent in 1996 to 30 percent in 2005 respectively [1]. In the year 2013, out of the nearly four million births in the United States, there were approximately three million were vaginal deliveries [2]. In Australia in 2009, 70 percent of women delivered vaginally, of which 58.1% had spontaneous vaginal delivery [3]. In anticipating complications and preparing for vaginal delivery, accurate pregnancy dating is very essential [1]. There are relatively few absolute contraindications to vaginal delivery, meaning that most women deliver vaginally.

Most health experts, including World Health Organization (WHO), do recommend vaginal delivery for women whose babies have reached full term. In comparison to other methods of childbirth, vaginal delivery is the simplest process of delivery [4].
