| Popis: |
Present methods of prenatal diagnosis are not applicable until at least 16 weeks of gestation. Most abortions for suspected congenital abnormality are therefore usually done in the second trimester of pregnancy. Abortions at over 20 weeks of gestation account for about 0.8% of all abortions for residents of England and Wales, but the operations are unpleasant and carry a significant morbidity. Screening the population for neural tube defects has led to a marked reduction in the recorded incidence of infants born with the condition. A survey in the Northern Region of England, with official statistics from Scotland, shows that in spite of the contribution made by selective abortion, there appears to be a genuine reduction in the population incidence of neural tube defect in Scotland. The diagnosis of chromosomal abnormalities, and to a lesser extent of neural tube defects, depends on amniocentesis and there is evidence of more delay in initiating amniocentesis for neural tube defect than for chromosomal tests, probably because of administrative delay associated with the use of serum alphafetoprotein screening. The possible impact of proposals to change the law concerning the limit of viability of the fetus on the practice of late abortion for congenital abnormality is examined. Abortion for congenital abnormality should be permitted after 22 weeks' gestation. |
