EVOLVING PATTERNS OF IATROGENIC MULTIFETAL PREGNANCY GENERATION - IMPLICATIONS FOR AGGRESSIVENESS OF INFERTILITY TREATMENTS

OBJECTIVE: Our purpose was to assess the changes in multifetal pregnancy generation as a function of utilization of ovulation stimulation and assisted reproductive techniques and to document the relative control of hyperstimulation between the methods. STUDY DESIGN: The methods of infertility treatment, number of fetuses, and outcomes of 220 patients referred for multifetal pregnancy reduction were compared over three time periods (1986 to 1989, 1991 to 1992, and 1992 to 1993). Clomiphene, human menopausal gonadotropin, and ovulation stimulation with urofollitropin were compared against gamete intrafallopian transfer, zygote intrafallopian transfer, and in vitro fertilization (assisted reproductive techniques). RESULTS: The proportion of multifetal pregnancies generated by assisted reproductive techniques has steadily risen from 26% in the first two time periods to nearly half in the last 2 years. However, the number and proportion of quintuplet and greater pregnancies from assisted reproductive techniques have steadily fallen while for ovulation stimulation the proportion has remained about one third. CONCLUSION: Despite considerably increased use and proportionate generation of triplet and quadruplet pregnancies, the incidence of quintuplets has fallen for assisted reproductive techniques while there has been no improvement for ovulation stimulation. Continued, greater vigilance, particularly in the use of human menopausal gonadotropin and urofollitropin, must be emphasized.