Pregnancy outcome after third trimester amniocentesis: a single center experience.

OBJECTIVE

To evaluate pregnancy outcome following late amniocentesis (>24 weeks of gestation).

STUDY DESIGN

A retrospective cohort of all women with singleton pregnancy that underwent late amniocentesis in one tertiary center.

RESULTS

Pregnancy outcome was validated in 168 women who underwent late amniocentesis. Overall, for the all study group the mean gestational age for amniocentesis was 31.6 ± 2.3 weeks and the mean gestational age at delivery was 38.1 ± 2. Indications for late amniocentesis included abnormal ultrasonographic findings (n = 120), suspected intrauterine infection (n = 23), advanced maternal age (n = 13), abnormal first or second trimester biochemical markers (n = 8) and others. The overall rate of spontaneous preterm delivery (<37 weeks) was 8% (13/168) with mean gestational age at delivery of 34.7 ± 1.3. In only five cases (3%), delivery occurred ≤ 34 weeks of gestation. In one case (0.60%) of amniocentesis performed at 32 weeks of gestation, delivery occurred within 48 hours and in other four cases (2.40%) delivery occurred within 10 days. When amniocentesis was performed due to ultrasonographic findings to rule out chromosomal abnormalities (n = 117/182), abnormal karyotype was found only in three cases.

CONCLUSIONS

The risk of significant prematurity following late amniocentesis is low. This information is important when counseling patients considering performing one.