Post dates pregnancy
Post term. In 5-10% of women their pregnancies continue beyond 294 days (42 completed weeks) and are described as being post-term. Such pregnancies are at increased risk of birth trauma and asphyxia as well as stillbirth and postnatal death. It is generally accepted that pregnancies should not be allowed to go beyond 42 weeks and randomized studies demonstrated that induction of labor at 41 weeks compared to expectant management, is associated with a substantial reduction in perinatal mortality
Post dates refers to pregnancies beyond the estimated date of delivery. It should be realised that such pregnancies are also at increased risk of perinatal death. Indeed, the risk of pregnancy loss (intrauterine, neonatal and infant death) increases with gestation from as early as 38 weeks (1.2 per 1000 ongoing pregnancies at 38 weeks to 2.4 at 40 weeks and 5.8 at 43 weeks)
- The risk of stillbirth is related to placental ageing but there is no specific sequence of deterioration in the fetal condition to direct surveillance. However, there is a rapid decline of amniotic fluid volume and antenatal surveillance should be based on assessment of amniotic fluid volume twice per week