Age of the uterus does not affect pregnancy or implantation rates; a study of egg donation in women of different ages sharing oocytes from the same donor.

The importance of age of the recipient (uterine age) with regards to pregnancy rate, delivery rate and miscarriage rate following oocyte donation was evaluated using retrospective data analysis of cases where two recipients from different age groups shared oocytes from a single donor and had equal numbers of embryos transferred. A total of 104 women (21-52 years of age) underwent a total of 104 cycles of oocyte donation. They were divided into groups according to age (group A: age 39 years or less and group B: age between 40 and 52 years). The minimum age difference between a pair of recipients was five years. Hormone replacement therapy (HRT) was given using oestradiol valerate (6 mg daily) for at least 10 days, followed by a combination of oestradiol with either intramuscular progesterone (100 mg daily), or vaginally administered micronized progesterone (300 microg daily). Women with ovarian function received down-regulation using a luteinizing hormone-releasing hormone (LHRH) analogue before hormone replacement was commenced. A total of 52 transfer cycles was performed in each age group and pregnancy, delivery and miscarriage rates were analysed as outcome measures; 20 pregnancies were achieved in each group (an identical pregnancy rate of 38.5%). In group A seven pregnancies miscarried out of 20 (35%), which was not significantly different from the rate in the older population, group B, where eight out of 20 pregnancies miscarried (40%). The delivery rate in group A was 25% (13 out of 52), again not significantly different from the delivery rate in group B of 23.1% (12 out of 52). In conclusion, using egg donation as a model, the decline in fecundity with age cannot be explained by uterine factors alone.

Serum placental protein 14 concentrations in the first trimester of ovum donation pregnancies.

The concentration of the endometrial glycoprotein placental protein 14 (PP14) has been measured at weekly intervals during the first trimester in serum obtained from women who had become pregnant naturally (n = 15, all singleton) or following ovum donation (n = 16, 15 singleton and one twin) after ovarian failure (n = 13), Turner's syndrome (n = 2) or post-chemotherapy (n = 1). The concentration of PP14 failed to rise in ovum donation pregnancies, and was significantly reduced compared to the concentration in natural conceptions from 5 to 13 weeks gestation (P < 0.05-0.01). These findings demonstrate that the corpus luteum is essential for the normal increase in serum PP14 in the first trimester. Furthermore, they suggest that progesterone is not the major stimulus to PP14 synthesis in early pregnancy.

Relaxin levels in ovum donation pregnancies.

STUDY OBJECTIVE: To investigate the relative contributions of the corpus luteum (CL) and the placenta to the circulating levels of relaxin during pregnancy. PATIENTS: Forty-one patients in whom pregnancy had been achieved by ovum donation. RESULTS: Relaxin was not detected in the serum of 36 patients; in the remaining 5, although it was detectable, the levels were markedly reduced when compared with those in normal pregnancies. CONCLUSION: These results demonstrate that the CL is essential for the maintenance of normal circulating levels of relaxin during pregnancy.

Pregnancies after in vitro fertilization and transfer of human blastocysts.

In a study of 29 cycles of IVF, ET was performed on day 5 after oocyte recovery when embryos had developed to the morula/blastocyst stage. Three preclinical pregnancies and three live births resulted (2 singleton and 1 twin), giving a viable PR per ET of 10%. It is concluded that while day 5 ET may well be important in terms of embryo biopsy for the preimplantation diagnosis of genetic disease, day 2 ET remains preferable for therapeutic IVF. Although these data would not support the introduction of day 5 ET into routine therapeutic IVF, delayed ET should be considered as an alternative approach to preimplantation diagnosis. Indeed, because the latter will generally involve the treatment of normal, fertile couples, it might be predicted that embryo survival rates, and thus the rate of pregnancy after day 5 ET, would be better than those presented here.