Introduction

Technology has afforded us the opportunity to diagnose an ever increasing number and proportion of anomalies. The decision to terminate or continue such pregnancies has become increasingly complex, as the dramatic increases in our ability to detect birth defects has challenged our capability to counsel about and to treat or ameliorate these problems. This chapter reviews the issues involved in the decision-making process surrounding discovery of a fetal anomaly and describes some of the recent advances in fetal therapies to correct and treat these conditions, including endoscopic procedures, fetal surgery, medical fetal therapies, and gene therapies.

The development of modern prenatal diagnostic procedures

Modern prenatal diagnosis began in the early 1970s with the use of amniocentesis for the diagnosis of cytogenetic and biochemical disorders (Nadler, 1968). Essentially, these procedures were done blindly, and were generally not performed until about 17 weeks of gestation to minimize the risks of damage to the fetus. Ultrasound also began to identify anomalies in the early 1970s, but it was not until the early 1980s that the quality of ultrasound imagery was sufficient for it to become a significant component of invasive procedures, thus enhancing their safety (Evans and Johnson, 1992).

A limited number of centers began to offer prenatal diagnostic services in the early to mid 1970s. However, the number of physicians who had the technical competence to perform the invasive procedures, and the number of laboratories that could handle the specimens, were small.