THE IMPACT OF MATERNAL AGE ON CLINICAL PREGNANCY AND SPONTANEOUS-ABORTION IN WOMEN UNDERGOING IN-VITRO FERTILIZATION AND GAMETE INTRAFALLOPIAN TRANSFER

The age at which women should be advised against proceeding with initial or further infertility treatment is one of the many unresolved questions in this area of women's health and was the subject of investigation in this study. One of the major difficulties in determining the impact of maternal age on outcomes is the practice of researchers (publishing in journals) and infertility practitioners (reporting to national registers) of coding age as a categorical rather than a continuous variable. In this study, groups of younger (<30 years) and older (>35 years) women undergoing assisted reproduction treatments were compared with regards to clinical pregnancy and spontaneous abortion rates following in vitro fertilization (IVF) or gamete intra-Fallopian transfer (GIFT). Response to different ovarian stimulation protocols was also assessed for the 2 groups. The significance of the relationship between maternal age, clinical pregnancy rates, spontaneous abortion rates and the type of treatment and stimulation protocol employed, was tested using a series of binomial distributions. The results indicated that maternal age adversely affects both clinical pregnancy rates and rates of spontaneous abortion, when summed across treatments and stimulation protocols. However, while the age/outcome relationship held for IVF, the GIFT by age relationship was not significant. Stimulation protocols using clomiphene citrate (CC) or gonadotrophin agonists (GnRHa) may impact negatively on older women. Since it is unlikely that these data will be replicated on larger prospective samples, the basis for counselling couples about the advisability of undergoing assisted reproduction after the maternal age of 35 years should incorporate both a knowledge of the statistical trends reported in both the literature and national registers, and careful assessment of each participant's unique characteristics and responses to treatment.