Aim To investigate the long term pregnancy outcome following mid trimester amniocentesis and chorionic villous sampling in the first trimester.

Methods Pregnancy outcome data was retrieved from hospital database (Astraia software gmbh and Terranova Healthware) for all invasive procedures done by a single operator between 2008-2010. Outcomes of 84 cases of amniocentesis and 24 chorionic villous samplings (CVS) were compared with controls.

Results The main indications for amninocentesis (n=84) procedure included: screen positive on combined screening (78.5%), early onset IUGR (1%), congenital anomalies found on nuchal or anomaly scan (16.6%), prenatal diagnosis for haemoglobinopathies (2%) and maternal request (1%). 16 cases were excluded from further analysis due to presence of congenital anomalies, early onset IUGR and termination of pregnancy (TOP) due to HbSS.

Indications of CVS (n=24) included: screen positive on combined screening (79.5%), congenital anomalies (8%) and prenatal diagnosis (12.5%). 2 cases had TOP due to Turner's syndrome. 19 cases were analysed (after excluding congenital anomalies and TOP cases) for long-term pregnancy outcome. In control group (n=90) all cases delivered beyond 36 weeks of gestation as compared to 66 out of 68 (97%; P=0.19) cases of mid trimester amniocentesis and 17 out of 19 cases (89.5%; P < 0.05) in CVS group.

Conclusion We report that patients undergoing amniocentesis have similar long-term pregnancy outcomes as matched controls; with patients undergoing chorionic villous sampling were more likely to deliver prior to 36 weeks.