The foetus' presentation and position affect how the foetus passes through the vagina.
Most normal births involve a combination of vertex presentation with anterior position.
Presentation refers to how the foetus is situated in the uterus, while the part of foetus that is closest to the cervix is termed the presenting part. The most common and safest birth position where the baby's head is the presenting part. Transverse lie or shoulder presentation . Here a caesarean section is always needed. Breech , where the baby's buttocks presents first.