A new classification system has been developed that can explain almost all pregnancy losses, providing patients with better post-care support. In the US, there are approximately 5 million pregnancies each year, with around 20% ending in a loss before the 20th week of pregnancy (miscarriage) and over 20,000 ending in a loss in or after the 20th week of pregnancy (stillbirth). However, until now, around half of these losses have been classified as “unspecified” by the medical community. This lack of explanation can lead to patients feeling responsible for the loss and can cause significant emotional pain.
Researchers at Yale University have analyzed 1,527 individual pregnancies that ended in a loss, excluding cases without sufficient material for examination. They then examined 1,256 placentas from 922 patients who had either miscarriages (70%) or stillbirths (30%). By adding the categories of “placenta with abnormal development” and “small placenta” to existing categories such as umbilical cord accidents, detachment, thrombosis, and infection, the new classification system was able to explain 91.6% of previously unspecified miscarriages. The most common pathological feature in unexplained miscarriages was dysmorphic placentas (86.2%), while the most common feature in unexplained stillbirths was a small placenta (33.9%).
The researchers suggest that pathological examination of the placenta after a pregnancy loss should be systematically performed and an essential part of post-care. This study has the potential to create a scientific basis for future preventive strategies. By identifying dysmorphic placentas, genetic anomalies in the nearly 1 million miscarriages that occur each year could be detected early. Similarly, the identification of small placentas could mark pregnancies as high-risk before a loss occurs. This new classification system has the potential to provide patients with better explanations for their losses and improve post-care support.
