Os Factores Genéticos na Perda Gestacional

• Author(s): Francisco, C ; Mendes, N ; Lima, A ; Martins, L ; Serrano, F
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.17/1338
• Origin: Repositório do Centro Hospitalar de Lisboa Central, EPE
• Subject(s): Genética; Fenómenos Genéticos; Perda Recidivante do Feto; Morte Fetal; Aborto Espontâneo
• Document Type: Article
• Language: Portuguese

Description

Pregnancy loss is the most common obstetric complication. Multiple factors have been associated with recurrent or sporadic pregnancy loss, and genetic factors, particularly at earlier gestational ages, are the most important ones. The proportion of miscarriages due to chromosomal factors decreases with increasing gestational age. The most common chromosomal abnormalities in early losses are autosomal trisomies, monosomy X and polyploidy. In later losses, aneuploidies are similar to those found in live newborns (trisomies 21,18 and 13, X monosomy and polysomy of sex chromosomes. In cases of recurrent miscarriage the most common cytogenetic changes are trisomies, polyploidy, monosomy X and unbalanced translocations. Identification of the causes of pregnancy loss facilitates the families’ grief and may indicate if there is the risk of repetition, in order to reduce recurrence. The investigation recommended in each case is far from consensual, and the cost/benefit analysis of diagnostic exams is essential. The determination of the karyotype of the products of conception is indicated in cases of fetal loss and recurrent miscarriage, while the parental karyotypes should be performed only in selected cases. Couples with identified genetic conditions should be counseled about reproductive options, including prenatal or pre-implantation diagnosis. Surveillance of a future pregnancy should be multidisciplinary and adjusted in each case. The cytogenetic factors, due to their high prevalence and complexity, have a fundamental, but still not completely clear, role in pregnancy loss.