The Principles of Clinical Cytogenetics - Extra Materials - Springer

276 Linda Marie Randolph
rate of 14/298 (4.7%). No culture failures were seen. The needle gauge was 20, and no difference in
outcome was seen in transplacental vs placental passage.
In 1988, the combined experience of six groups, including the above-mentioned study, was
reviewed (60). The total loss rate in 1240 pregnancies of known outcome ranged from 1% to 4.7%.
Cell culture and amniotic fluid α-fetoprotein measurements were satisfactory. The conclusion was
that EA is feasible, but that other safety issues had not been adequately addressed, such as congenital
orthopedic anomalies and neonatal pulmonary compromise, which had been seen in some babies
born after mid-trimester amniocentesis (61).
Several other studies were published in the early 1990s (62–67). In one paper, 505 amniocentesis
procedures were performed between 11 and 15 weeks’ gestation. In all but 3 pregnancies, follow-up
information was available, including 16 fetal losses (3.1%)—10 in the 2 weeks after the procedure
and 6 within the 28th week. The authors reported a significantly higher risk for fetal loss when the
amniocentesis was performed at the 11th–12th week of gestation compared with the 13- to 15-week
group. The fetal loss rate between the 12- to 13-week and the 14- to 15-week groups showed no
statistically significant difference. They concluded that early amniocentesis is “a valid alternative to
traditional amniocentesis” (62).
In their 1990 paper, Elejalde et al. performed a prospective controlled study involving 615 amniocenteses
performed between weeks 9 and 16 of gestation, and they reviewed previous EA studies
(63). Their results showed that amniocentesis after the 9th week of pregnancy does not appear to
differ significantly in its complications and outcome from the results of the same procedure at 15–16
weeks or later. The issue of pseudomosaicism was also addressed and will be covered more fully later
in this chapter.
Penso et al. in 1990 (64) performed amniocentesis in 407 women between gestational ages of 11
and 14 weeks and compared the safety and accuracy with data obtained from collaborative studies of
amniocentesis performed later in the second trimester. Theirs was the first report to provide information
regarding neonatal outcome associated with EA. The spontaneous abortion rate within 4 weeks
of the procedure was 2.3%, and the fetal loss rate was 6.4%. Orthopedic postural deformities, including
club feet, scoliosis, and congenital dislocation of the knees and hips, were seen in eight newborns,
three of whose mothers had postamniocentesis leakage of amniotic fluid. A total of 10 women in the
study (2.6%) had postprocedure fluid leakage. It appeared that the orthopedic deformities might be
related to a postprocedure history of amniotic fluid loss. They concluded that the accuracy, risks, and
complications were similar to those of traditional amniocentesis.
In 1990, Hanson et al. reported their increased practitioner experience and use of continuous
ultrasonographic guidance in EA of gestations from 10 to 14 weeks (65). The needle gauge was
changed from the 20-gauge needle used in their 1987 study to 22 gauge, and the volume of fluid
removed was generally less. Pregnancy outcome was reported for 523 patients, of whom 12 (2.3%)
had a postprocedural loss. This compared favorably with their previously reported loss rate of 4.7%.
Of eight women with postprocedure amniotic fluid leakage, one had a baby at term with a dislocated
knee. Another experienced fetal death 3 weeks after the amniocentesis, and the rest had normal term
deliveries.
In a smaller series, 105 EA procedures were performed (66). There were 2 pregnancy losses in the
64 patients for whom outcome information was available at the time of publication, and 4 congenital
anomalies were seen in the 66 delivered babies: 1 imperforate anus, 1 hemangioma of the tongue, and
2 cases of positional talipes that required no treatment. These were apparently unrelated to amniotic
fluid leakage.
Crandall et al. (67) retrospectively studied 693 consecutive EA (prior to 15 weeks) cases, which
had a spontaneous abortion rate (to 28 weeks gestation) of 1.5%, compared with a nonrandomized, later
control group of 1386 women having traditional amniocentesis, whose spontaneous abortion rate was
0.6%, a statistically significant difference. In their review of background risk of pregnancy loss in the
second trimester, they concluded that “at least some of the pregnancy loss subsequent to early amnio-