Research Article

Theoretical Model of the Relationship between Single Embryo Transfer Rate and Multiple Pregnancy Rate in Japan

Table 2

Approximation formula with 𝑅 2 .

Types of ARTApproximation formula
Linear approximationQuadratic approximationExponential approximation

Fresh
 IVF-ET π‘Œ = βˆ’ 0 . 2 5 𝑋 + 2 2 . 7 8 ( 𝑅 2 = 0 . 9 9 2 ) π‘Œ = 0 . 0 0 3 2 𝑋 2 βˆ’ 0 . 6 1 𝑋 + 3 1 . 9 8 ( 𝑅 2 = 1 ) π‘Œ = 3 9 . 7 0 4 e x p ( βˆ’ 0 . 0 2 8 𝑋 ) ( 𝑅 2 = 1 )
   π‘Œ ( 𝑋 = 1 0 0 ) βˆ’2.04 3.79 2.41
 ICSI π‘Œ = βˆ’ 0 . 2 4 𝑋 + 2 0 . 5 8 ( 𝑅 2 = 0 . 9 9 6 ) π‘Œ = 0 . 0 0 2 6 𝑋 2 βˆ’ 0 . 5 0 𝑋 + 2 6 . 9 0 ( 𝑅 2 = 1 ) π‘Œ = 3 4 . 5 7 8 e x p ( βˆ’ 0 . 0 2 8 𝑋 ) ( 𝑅 2 = 1 )
   π‘Œ ( 𝑋 = 1 0 0 ) βˆ’3.08 3.25 2.10
 Subtotal π‘Œ = βˆ’ 0 . 2 4 𝑋 + 2 1 . 8 2 ( 𝑅 2 = 0 . 9 9 2 ) π‘Œ = 0 . 0 0 3 2 𝑋 2 βˆ’ 0 . 5 8 𝑋 + 3 0 . 3 9 ( 𝑅 2 = 1 ) π‘Œ = 3 7 . 6 4 5 e x p ( βˆ’ 0 . 0 2 8 𝑋 ) ( 𝑅 2 = 1 )
   π‘Œ ( 𝑋 = 1 0 0 ) βˆ’2.58 4.04 2.29

Frozen
 Frozen
 (intra-uterine)
π‘Œ = βˆ’ 0 . 2 5 𝑋 + 2 3 . 6 0 ( 𝑅 2 = 0 . 9 9 9 ) π‘Œ = 0 . 0 0 1 9 𝑋 2 βˆ’ 0 . 4 9 𝑋 + 3 1 . 5 1 ( 𝑅 2 = 1 ) π‘Œ = 6 8 . 0 8 3 e x p ( βˆ’ 0 . 0 3 5 𝑋 ) ( 𝑅 2 = 0 . 9 9 8 )
   π‘Œ ( 𝑋 = 1 0 0 ) βˆ’1.09 1.22 2.06
 Subtotal π‘Œ = βˆ’ 0 . 2 4 𝑋 + 2 3 . 3 7 ( 𝑅 2 = 0 . 9 9 9 ) π‘Œ = 0 . 0 0 2 0 𝑋 2 βˆ’ 0 . 5 0 𝑋 + 3 1 . 6 1 ( 𝑅 2 = 1 ) π‘Œ = 6 5 . 5 9 0 e x p ( βˆ’ 0 . 0 3 4 𝑋 ) ( 𝑅 2 = 0 . 9 9 8 )
   π‘Œ ( 𝑋 = 1 0 0 ) βˆ’0.98 1.59 2.19

Grand total π‘Œ = βˆ’ 0 . 2 4 𝑋 + 2 2 . 2 0 ( 𝑅 2 = 0 . 9 9 6 ) π‘Œ = 0 . 0 0 2 4 𝑋 2 βˆ’ 0 . 5 2 𝑋 + 3 0 . 5 2 ( 𝑅 2 = 1 ) π‘Œ = 4 6 . 1 4 8 e x p ( βˆ’ 0 . 0 3 𝑋 ) ( 𝑅 2 = 0 . 9 9 9 )
   π‘Œ ( 𝑋 = 1 0 0 ) βˆ’1.40 2.03 2.30

ART: assisted reproductive technology.
IVF-ET: 𝑖 𝑛
𝑣 𝑖 𝑑 π‘Ÿ π‘œ fertilization and embryo transfer.
ICSI: intracytoplasmic sperm injection.
X: SET pregnancy rate. π‘Œ : multiple pregnancy rate.