The risks associated with post term pregnancy: a literature review

Abstract

The purpose of this paper is to conduct a critical literature review of the risks associated with induction of labour and a conservative approach to post term pregnancy. The main aim was to establish whether a conservative approach to post term pregnancy is associated with increased rates of perinatal mortality and morbidity, and whether induction of labour reduces these rates. Electronic databases and texts were examined. The findings were that the rates of caesarean section, instrumental birth, use of analgesia, incidence of fetal heart rate abnormality, meconium aspiration syndrome and fetal size were similar in both approaches to care. It appears that perinatal mortality rates increase in post term pregnancy yet the literature varies as to when this increase becomes significant. Induction of labour after 41 weeks gestation reduces the rates of perinatal mortality, however, the amount to which mortality rates are decreased by performing induction of labour at this gestation also varies within the literature. Therefore, it is difficult to given concise dates about when induction of labour should be recommended. Women should be informed of the risks associated with both approaches to care, and based on the review findings, they should be offered induction of labour between 291 days and 294 days, or between 41+4 and 41+7 weeks gestation. However, their preference for either approach should be respected.