Implementation of AFL Monitoring in Clinical Use

The overall objective of this randomized controlled trial is to develop a clinical standard procedure for measuring lactate in amniotic fluid (amniotic fluid lactate = = AFL) during childbirth before oxytocin stimulation is started. The aim is to reduce the need for emergency caesarean section during dysfunctional labour. The aim is also to study how different substances (oxytocin and Samarin®) affect uterine metabolic status during labour. Labour dystocia, i.e. prolonged labour, occurs in up to 30% in primipara deliveries and in about 20% of all the deliveries. In 2016, in Finland oxytocin stimulation was used in 42% of all the deliveries. The uterus, myometrium, is one of the largest muscles in the human body and consists mainly of smooth muscle cells. During the contractions the myometrial vessels also contract, causing momentary hypoxia and activation of anaerobic metabolism: O2 and pH levels of the muscle cell decreases and the lactate concentration increases. After the contraction, the blood circulation is restored and the anaerobic metabolites gradually dissolve. Myometrium requires a sufficiently long break between the contractions to recover. In dysfunctional labour the anaerobic metabolites accumulate in the myometrium. Accumulation of lactate has proved significantly to reduce the spontaneous contractions of myometrium and hinder myometrium calcium metabolism, which in turn reduces the strength of the contractions. Amniotic fluid lactate is known to reflect the metabolic state of the uterus during the labour. Prolonged labour can in many aspects be compared to the athlete's tired muscles. Many of today's athletes try to control the accumulation of lactic acid in their muscles during training by drinking baking soda (bicarbonate) dissolved in water one hour before their physical activity. Bicarbonate is known to function as a lactic acid buffer. Bicarbonate is considered as food and is sold in grocery stores as baking soda and for example as Samarin®. S