Background:

The World Health Organization (WHO) advises against recumbent or supine position for longer periods during labour and birth and states that caregivers should encourage and support the woman to take the position she finds most comfortable. It has been suggested that upright positions may improve childbirth outcomes and reduce the risk for instrumental delivery.

Objective:

The primary objective was to test the hypothesis that birthing on the "BirthRite" ® seat will result in a reduction in the number of primiparous women delivered instrumentally.

Method:

A power calculation showed (α = 0.05 β = 0.2) a requirement of 460 participants in each of the two arms of the trial in order to test for a 40% reduction (from 15% to 9%) of instrumental deliveries in primiparous women at a maternity unit in southern Sweden. It was decided to subject the study to a feasibility test by conducting a pilot-study in which 68 women were randomised to give birth on the birthing seat or to give birth in any other position but on the "BirthRite" ® seat. Randomization to birth on the birthing seat or in any other position took place when the participant's cervix was fully dilated. The primary outcome measurement was the number of instrumental deliveries. Secondary outcome measurements included oxytocin augmentation, perineal trauma, and blood loss administration of oxytocin for augmentation of labour, length of the second stage of labour, perineal trauma, perineal oedema, maternal blood loss and haemoglobin, apgar scores, cord pH and transfers to the Neonatal Intensive Care Unit(NICU).

Inclusion Criteria:

• The pilot study included primiparous women who understood the Swedish language sufficiently well to receive information and give informed consent or refusal for participation.
• Pregnancy must have been normal, with a singleton fetus in cephalic presentation and the onset of labour occurring between gestation weeks 37 + 0 and 41 + 6.
• Women having diet treated pregnancy diabetes were also included.
• Obstetric primiparous women with former caesarean section were included as well as those induced because of premature rupture of membranes (PROM).

Exclusion Criteria:

• Multiparous women were excluded from the pilot study.
• Primiparous women were excluded in cases of birth before week 36 + 6, breech presentation, maternal BMI over 30, multiple pregnancy or infectious disease.
• Primiparous women with pre-eclampsia or other conditions that require medical care were not eligible for the pilot study.