Effects of mid-trimester induced abortion on the subsequent pregnancy.

The outcome of the pregnancy following (a) a mid-trimester termination of pregnancy (TOP) for fetal neural tube defect (NTD) (77 women = group 1); (b) mid-trimester TOP for fetal Down's syndrome (13 women = group 2); (c) delivery of a baby with NTD (119 women = group 3) was studied. The prenatal fetal loss was relatively high in all groups. In group 1 it was similar to that found in other studies after first trimester TOP, in group 2 it was associated with advanced maternal age and the unexpected finding in group 3 was not attributable to advanced maternal age. It is suggested that a previous NTD per se might increase the risk of fetal loss in the next pregnancy. A previous mid-trimester TOP for NTD was not associated with an increase in premature labour, small for dates babies or congenital abnormality in the next pregnancy, but there was a slight increase in the number of babies weighing less than 2500 g.