Termination of pregnancy due to fetal abnormalities performed after 23 weeks' gestation: analysis of indications in 144 cases from a single medical center.

Objective: To assess the indications for late termination (> or =23 weeks' gestation) of pregnancy (LTOP), and to evaluate the rate of cases potentially diagnosable earlier.

Methods: Cases of singleton pregnancy ending in LTOP due to fetal abnormalities in our institute between 1/1998 and 12/2005 were retrospectively reviewed. The women were divided into two groups according to the sequence of events that led to LTOP: Group 1 - the first test indicating an abnormal finding was performed < or =23 weeks' gestation, but LTOP was performed >23 weeks; Group 2 - the first test indicating an abnormal finding was performed > or =23 weeks of gestation, or the fetal prognosis was not certain at the time of diagnosis and there was a medical recommendation to continue investigation.

Results: There were 144 cases of LTOP (average gestational age 26.2 +/- 3.4 weeks). More than 70% of the cases were aborted because of chromosomal/genetic indication in Group 1; many of them could have been detected earlier in pregnancy, while about 80% of the cases were aborted because of structural abnormalities in Group 2 (p < 0.001). The structural anomaly could have been diagnosed earlier in 56 cases ( approximately 74%) if the pregnant woman had undergone an earlier anomaly scan. In another 13 cases (9%), fetal prognosis was not certain and continuing prenatal investigation was required.

Conclusions: The most common indications for LTOP were structural abnormalities (91 cases, 70%) which included the central nervous system (26 cases, 29%), cardiac abnormalities (24 cases, 26%), and multiple malformations (18 cases, 20%). The diagnosis of fetal anomaly could have been made earlier in more than half of the pregnant women undergoing LTOP.