Comparison of the lactate-pyruvate ratio during labour and delivery in singleton and twin pregnancy.

Oxygen utilisation at the tissue level was investigated by the use of lactate-pyruvate (LP) ratio in forty women; twenty with term twin pregnancy, with a matched controlled group of twenty women with term singleton pregnancy. The lactate-pyruvate ratio in twin pregnancy was significantly higher than in singleton pregnancy at term (p < 0.05). There was also significantly higher LP ratio in advanced labour in twin pregnancy than in singleton pregnancy (p < 0.001). Similarly, the venous cord blood LP ratio of twin II was higher than in twin I. Our findings have thus demonstrated more marked anaerobic metabolism in twin pregnancy than in singleton pregnancy. Secondly, the second twin is more involved in anaerobic metabolism as a result of relative oxygen deficiency, than twin I. This may to some extent account for the higher morbidity and mortality in twin pregnancy, compared to singleton pregnancy, and in twin II compared to twin I.