Strong Association Between Placental Pathology and Second-trimester Miscarriage

The survival probability of early human conceptions is very low. At least 73% of natural single conceptions have no real chance of surviving six weeks of gestation [1]. After six weeks, survival rates improve rapidly as 90% of the remainder will survive to term. This low fetal loss rate is close to the low rates of 1% 2.9% for different methods of artificial reproduction [2]. From 16 weeks the rate of loss reduces further, to around 1% [3,4]. Miscarriage is the loss of pregnancy before fetal viability and has a pooled risk of 15.3% (95% CI: 12.5-18.7) [5]. The population prevalence of women who have had one miscarriage is 10.8% (95% CI: 10.3 -11.4). As there is a great need for better knowledge and services, a recent editorial article in The Lancet pleaded for worldwide reform to improve the care of women who have had a miscarriage [6].