Fetal loss associated with second trimester amniocentesis

To evaluate the fetal loss rate associated with second trimester amniocentesis.

All cases of pregnant women ≥35 years old with gestational age beyond 16 weeks between 1997 and 2006 were included in this study. The study group consisted of all cases that the patients decided to have second trimester genetic amniocentesis. The control group was a randomized selection of pregnant women who refused any procedures. The ratio of the study case to the control case was 2:1. The fetal loss rates after amniocentesis before 24, and 28 complete weeks and the pregnancy outcome were analyzed.

2,990 cases in the study group and 1,495 cases in the control group were used for this analysis. The mean maternal age in the study group and control group were 36.89 ± 1.63 and 36.78 ± 1.59 years old, respectively (P = 0.239). The procedure-related fetal loss before 24 and 28 complete weeks were 0.17 and 0.50%, respectively. The most common presenting symptom before fetal loss in the study cases was abdominal pain. Almost all of the cases leading to abortion had symptoms initiated after 48 h post procedure. Significantly higher chances of abortion occurred in pregnant women ≥41 years old (P = 0.008).

The procedure-related fetal loss rates in pregnant women ≥35 years old after amniocentesis before 24 and 28 complete weeks were 0.17 and 0.50%, respectively. The certain factors influencing the risk of fetal loss might be independent of the amniocentesis procedure.