A report of early (13 + 0 to 14 + 6 weeks) and mid-trimester amniocenteses: 10 years' experience.

OBJECTIVE

To report in singleton pregnancies the post-procedure safety and maternal complications of early amniocenteses performed between 13 + 0 and 14 + 6 weeks of gestation and mid-trimester amniocenteses performed between 15 + 0 and 18 + 6 weeks of gestation.

METHODS

The study was carried out at the Prenatal Diagnosis Center, Siena University, Italy, during a 10-year period, following the Regional Protocol for Prenatal Diagnosis. Our study population included 3769 amniocenteses, 475 early and 3294 mid-trimester. Complications considered included miscarriage (immediately after the procedure and until 24 weeks of gestation), blood-stained amniotic fluid, failed cell culture, amniotic fluid leakage, preterm premature rupture of the membranes (PROM), preterm delivery and presence of neonatal talipes equinovarous.

RESULTS

Cytogenetic anomalies were found in 111 cases (2.9%), 18 occurring early and the other 93 in mid-trimester. Miscarriage occurred in two cases in the early amniocentesis group (0.4%) and in ten cases among the mid-trimester group (0.3%). The overall loss of pregnancies due to amniocentesis in this study was 0.3%. Amniotic fluid was stained in 1.2% in the early group and 0.9% in the mid-trimester group. Amniotic fluid leakage was noted in 1.4% and 1.2%, preterm PROM was noted in 3.3%) and 3%, and preterm delivery occurred in 8% and 7.6%, respectively. There were no cases of failed amniotic culture and no cases of talipes equinovarous documented.

CONCLUSIONS

The risks of early amniocentesis performed between 13 + 0 and 14 + 6 weeks appear to be comparable to those of mid-trimester amniocentesis and thus early amniocentesis could be offered to the parents, as an alternative to chorionic villus sampling, in order to obtain cytogenetic results earlier in pregnancy without a significantly increased risk for both mother and fetus. Further operators' experience with the method, based on long and accurate follow-up, and further studies are necessary to assess the safety of the method.