Chorioamniotic separation after second-trimester genetic amniocentesis: importance and frequency.
OBJECTIVE
To determine the frequency and importance of chorioamniotic separation (CAS) after second-trimester genetic amniocentesis.


METHODS
In part 1 of the study, ultrasonography (US) databases were reviewed for cases of CAS. In part 2, a study population of 388 women undergoing amniocentesis underwent directed US examination for assessment of CAS 15 minutes and/or 2 weeks after amniocentesis. CAS, when present, was graded. A control population consisted of 363 women undergoing amniocentesis in whom the membranes were not assessed.


RESULTS
In part 1, a review of 23,883 records revealed seven cases of complete CAS, with three deaths, two preterm deliveries, and one emergency cesarean section delivery due to fetal distress. In two of these cases, there were extremity deformities at birth. In part 2, CAS was present in 98 (25%) of 388 women at some point. There was no association between CAS and procedural variables. There was no substantial difference in morbidity between patients with and those without CAS, between patients with different grades of CAS, or between the study and control populations.


CONCLUSIONS
Small degrees of CAS are frequently present after amniocentesis but are not detected because the membranes are not specifically evaluated. Complete CAS is less frequent.
Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
D
D
Levine
P W
PW
Callen
S G
SG
Pender
C R
CR
McArdle
L
L
Messina
A
A
Shekhar
G P
GP
Wong
D000328:Adult; D000649:Amniocentesis / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D000650:Amnion / Q000000981:diagnostic imaging / Q000293:injuries*; D016477:Artifacts; D002823:Chorion / Q000000981:diagnostic imaging / Q000293:injuries*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008423:Maternal Age; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D013997:Time Factors; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging