Spontaneous abortion - Causes and Symptoms

Definition

Spontaneous abortion means the non-induced death of the embryo / fetus or the expulsion of the products of conception (fetus and placenta) before the twentieth week of gestation. During this time, the threat of an abortion is signaled by vaginal bleeding, associated with symptoms such as pelvic cramp pain, cervical dilation and passage of material.

If fetal death occurs after the twentieth week we speak of late death of the fetus. There are also early abortions (if they occur before the 12th week of gestation), recurrent abortions (> 2 consecutive spontaneous abortions) and induced for therapeutic reasons (when the woman's health is in danger or the fetus is dead or has malformations incompatible with the life).

Isolated spontaneous abortions can be caused by viral infections (mainly cytomegalovirus, herpes virus, parvovirus and rubella virus), major traumas, immunological alterations or chromosomal abnormalities that can cause intrauterine fetal damage. Other common causes may include maternal lutein phase defects, improperly treated endocrine diseases (eg, polycystic ovary syndrome, hypothyroidism, hyperthyroidism and diabetes mellitus), severe chronic kidney disease and hereditary thrombotic disorders.

Risk factors for a miscarriage include: age less than 20 years or over 35, drug-alcohol abuse, excessive thinness or large weight loss, intake of particular drugs and presence of structural abnormalities of the uterine cavity (ex. polyps, fibroids and adhesions that hinder the embryo implantation).

Spontaneous abortion is a rather common occurrence, for which an incidence rate of approximately 35% of pregnancies is estimated. Often the event is so early as to go unnoticed. In the great majority of cases it is a sporadic and not repeated episode in the same woman.