Table 4. Association between the number of transferred high quality embryos and single and multiple pregnancy rates by age group
Single gestation
n (%)
 
PR
Multiple gestation
n (%)
 
PR
 
P* Value
Age group Nº Embryos
1 13 (100) - 0 (00.0) - 0.009
≤ 35 years 2 142 (69.3) 1.00 63 (30.7) 1.00 -
3 38 (59.4) 0.85 26 (40.6) 1.32 -
4 2 (100) - 00 (00.0) - -
 
1 9 (100) - 0 (00.0) - 0.004
36 e 39 years 2 46 (68.7) 1.00 21 (31.3) 1.00 -
3 26 (63.4) 0.92 15 (36.6) 1.17 -
4 1 (16.7) 0.24 5 (83.3) 2.66 -
 
1 11 (100) - 0 (00.0) - 0.001
≥ 40 years 2 24 (96.0) 1.00 1 (04.0) 1.00 -
3 28 (84.8) 0.88 5 (15.2) 3.80 -
4 4 (66.7) 0.69 2 (33.3) 8.32 -
* P for linear trend test (chi-square Pearson)