Effect of Amniotomy on Outcome of Spontaneous Labour

Intentional artificial rupture of the amniotic membranes during labour, called amniotomy or 'breaking of the water's, is one of the most commonly performed procedures in modern obstetric and midwifery practice. The primary aim of amniotomy is to speed up uterine contractions and therefore shorten the length of labour. However there are concerns regarding unintended adverse effects on the woman and baby. A prospective observational study was conducted to determine the effectiveness and safety of routine procedure of amniotomy to shorten the duration of labour (prolonged or not) in Mymensingh Medical College & Hospital, Mymensingh, Bangladesh from July 2011 to December 2011. One hundred low-risk women with spontaneous onset of labour at term with singleton fetus in cephalic presentation and intact amniotic membranes and a cervical dilatation between 4 and 5cm were conventionally assigned to have amniotomy during the course of labour. Maternal demographics, duration of labour (prolonged or not), maternal and perinatal outcome were considered as major outcome. Majority (49.0%) of the patients belonged to 21-25 years age group and primigravida was predominant and most of them had middle socio-economic conditions. More the three-fourth (89.0%) of the patients had head engaged. Rh-positive and negative were found 96.0% and 4.0% respectively. The primigravidae required 10.07±2.17 hours in 1st stage of labour and had 1.51±0.5 hours duration of 2nd stage of labour. In case of multi-gravidae it was 6.07±2.06 hours in 1st stage of and 1±0.5 hours in 2nd stage of labour. There was a marked reduction of amniotomy-delivery interval time in this study, which was 3 hours 40 minutes and whereas mean cervical dilatation was 4cm during amniotomy. Almost three fourth (72.0%) cases delivered vaginally among which, with episiotomy in 49.0% and without episiotomy in 23.0%. Instrumental delivery was in 9.0% of which 4.0% by forceps, 5.0% by vaccum extraction and 14.0% underwent LUCS. Still birth was found 2.0%, asphyxiated 3.0% and prenatal death 1.0%. In terms of referral to neonatal care unit it was found that 7.0% were asphyxiated. Asphyxia and low APGAR score was 4.0%, low birth weight 9.0%, instrumental delivery was 5.0%, Rh incompatibility was 2.0%. Only 1.0% babies needed admission to neonatal care unit and were intubated. So, Amniotomy significantly reduced the duration of the first stage of labour without affecting the oxytocin requirement, the rate of caesarean section and newborn outcome.