Prospective study of amniocentesis performed between weeks 9 and 16 of gestation: Its feasibility, risks, complications and use in early genetic prenatal diagnosis

Abstract

This paper demonstrates that the outcome of amniocenteses performed between the 9th and the 14th weeks is similar to that of amniocenteses performed between the 15th and 20th weeks. We have performed and prospectively followed 615 amniocenteses between the 9th and 16th weeks of gestation. The outcome, risks, and complications are similar to those of amniocenteses at the usual time (after 15 weeks) and to the other groups of early amniocentesis (before 15 weeks). Early amniocentesis differs from amniocentesis at the usual time in that it carries higher rates of fetal losses and of amniotic fluid leakage, more confined cytogenetic abnormalities, and an increased number of patients who have the procedure postponed. Two cultures (0.32%) failed to produce results, 595 (96.7%) samples were obtained at the first tapping, 20 (3.3%) at the second attempt. alpha-Fetoprotein levels reach their maximum at 13 weeks. Amniocenteses between 15 and 16 weeks (293, or 47%) constitute the control group, those between 9 and 14 weeks (322) the experimental group. Early amniocentesis appears to be a safe early genetic prenatal diagnosis technique, an alternative to chorionic villi sampling.

Diagnóstico pré-natal

“…Esse último obstáculo pode ser contornado por uma filtração das células durante a punção, concentrando-as em pequenos volumes. A punção amniótica precoce pode ser realizada a partir da nona semana (Elejalde et al, 1990), mas, preferencialmente, a partir da 13ª semana e um dos critérios muito importante para que haja sucesso no cultivo celular é que o feto possua a distância cabeça-nádegas superior a 37mm (-Byrne et al, 1991).…”

Transient anhydramnios after early amniocentesis complicated by membrane rupture

“…In addition, a case of CDH presenting neonatal gastric perforation on the fourth day of life due to strangulation of the incarcerated stomach 7 has been reported.…”

“…Acute gastrointestinal complications of CDH during the neonatal period are mainly caused by the incarceration of the stomach, the small intestines and/or the colon 7 . It is likely that the mechanical activation of the gastrointestinal tracts and air swallowing after birth lead to volume enlargement and the deterioration of blood supply, resulting in mechanical and ischemic damage in the digestive tract herniated to the thoracic cavity through a small diaphragmatic defect.…”

“…Before advocating the use of this invasive therapy, the natural history of such events needs to be well defined, especially when the expectant management is considered as a failure. Usually reseal is expected to occur within 7 days [6][7][8] . Exceptional late normalization of the AF volume was reported by Borgida in three out of 11 cases, on day 31, 43 and 51, although the precise timing of normalization could not be determined as ultrasound scans were performed weekly 3 .…”

Evaluación de la Amniocentesis Precoz en una Institución Brasileña de Diagnóstico Prenatal

“…Antes de doce semanas, las tasas de error en el cultivo y pérdida fetal asociados al procedimiento son más elevadas (5). En Brasil, la AP fue introducida en 1992 (6) y desde entonces ha sido rutinariamente ofrecida en el Instituto de Medicina Fetal y Genética Humana.…”