In order to achieve a clinical pregnancy rate higher than that achieved following initial adoption of in-vitro fertilization embryo transfers, more than one embryo is transferred. This has led to a substantial increase in unwanted multiple pregnancy rates with IVF as compared with natural conception. What is therefore required is a simple, clinically useful embryo scoring system, to reflect embryo developmental potential, which will enable the selection of the optimal number of embryos to transfer in order to achieve the maximum pregnancy rate with a low incidence of high order multiple pregnancies. We believe that the Cumulative Embryo Score (CES) achieves these aims. On the day of embryo transfer the grade of each embryo transferred was multiplied by the number of blastomeres to produce a score for each embryo, and summation of the scores obtained for all the embryos transferred gave the CES. The grouped pregnancy rates obtained rose as the CES increased to maximum of 42. A continued increase in the CES above 42 did not result in any further rise in the pregnancy rate. However, an analysis of all our IVF pregnancies showed that the multiple pregnancy rate continued to rise above a CES of 42. By restricting the CES per embryo transfer to 42, 78% of triplet pregnancies and 100% of the quadruplet IVF pregnancies could have been predicted and potentially avoided.

No abstract

Uterine arterial blood flow was studied at defined times during the ovarian or menstrual cycles. Transvaginal colour pulsed ultrasound was used to identify the vessels in 23 healthy women. Blood flow impedance as reflected by the pulsatility index (PI) was determined for both arteries on 132 occasions. There was no significant difference in the PI values between the right and left arteries. The average PI value was used for subsequent analysis (range 0.5-5.6; mean 2.8). Peak mean PI values occurred on day 1 of menses (4.6), the day of the plasma oestradiol peak (3.7) and the day of the LH peak plus 3 (2.9). The lowest mean PI values (indicating the least impedance to blood flow) occurred on the day of the LH peak minus 6 (2.6), and the day of the LH peak plus 9 (1.9). There are complex temporal relationships between uterine blood flow, ovarian morphology, the concentrations of plasma oestradiol and progesterone and the thickness of the endometrium.