ABSTRACT

Dystocia also referred to as obstructed labour is a public health issue and the major cause of maternal and perinatal morbidity and mortality especially in developing countries. It is caused by myometrial acidosis which inhibits Ca²⁺ and thus leads to weaker and ineffective contraction during labour. The incidence of dystocia is not well known as there is no consensus on the duration of normal labour.However, dystocia remains a poorly diagnosed area. This study was carried out on 50 mice to determine the effect of sodium bicarbonate on myometrial acidosis. The mice were grouped into five, of which four of the group was treated with nifedipine, nifedipine alone and oxytocin alone, 5% sodium bicarbonate, and 5% sodium bicarbonate alone and nifedipine alone. The arterial acidity (PCO₂) mean value recorded was 42.00±1.00 for the control group, 37.50±2.00 for nifedipine, 37.00±2.00 for nifedipine and oxytocin, 42.00±1.00 for sodium bicarbonate and 14.50±14.50 for sodium bicarbonate and nifedipin group. While for blood pH, the mean value recorded was 7.37±0.005 for the control, 7.56±0.045 for nifidepin, 7.52±0.085 for nifedipin and oxytocin, 7.42±0.060 for the sodium bicarbonate and 3.94±3.945 for sodium bicarbonate and nifedipine group. Among the study group only the sodium bicarbonate and nifedipin group showed a decrease in PCO₂ and blood pH, while 5% bicarbonate had no effect on arterial acidity and blood pH. Both PCO₂ and blood pH showed no significance difference (p > 0.05). This study proved that 5% sodium bicarbonate may not be effective in assuaging myometrial acidosis which causes dystocia.