Table 5. Life Table of egg survival and probabilities during the first two weeks of development derived solely from Hertig’s data.

The table is modelled on Leridon’s life table ²⁶ and includes his values for survivors and data from Hertig ⁵. Probabilities are also shown for each stage of the early development process. Medians and 95% confidence intervals derived from a bootstrap analysis of Hertig’s data indicate the precision in the estimates for fertilisation and embryo loss in the first two weeks. *Although Leridon’s values are based on Hertig, they do not fully match. Leridon reports losses of 15 and 27 in the first and second weeks respectively. However, Hertig’s 60% loss of abnormal pre-implantation embryos implies 25 (0.6 × 42) losses in the first week leaving 58, and 16 (58 × (6/21)) losses in the second week, leaving 42. ^¥A value of π _SOC = 0.90 was used to avoid the calculation of probabilities greater than 1.

Week after Ovulation	Biological Description	Survivors (Leridon 26)	Survivors (Hertig 5)	Bootstrap Median [95% CIs]
	Number of Cycles	100	100	100 [100, 100]
0	Fertilised Eggs	84	83	84 [39, 227]
1	Implanted Embryos	69*	58	58 [41, 74]
2	Missed First Period	42	42	42 [26, 59]
Probabilities	Biological Description	Probabilities	Probabilities	Bootstrap Median [95% CIs]
π SOC × π FERT	Fertilisation per cycle	0.84	0.83	0.84 [0.39, 2.27]
π FERT (when π SOC = 0.90 ¥)	Fertilisation per ideal insemination	0.93	0.93	0.93 [0.43, 2.52]
π HCG	Fertilised egg implanting	0.82*	0.70	0.69 [0.27, 1.28]
π CLIN	Implanted egg to clinical recognition	0.61*	0.71	0.71 [0.50, 0.91]
π HCG × π CLIN	Fertilised egg to clinical recognition	0.50	0.50	0.50 [0.20, 0.88]