Table 3. Variables for Predicting the risk of ectopic pregnancy after in vitro fertilization-embryo transfer.
Variables OR (95% CI) p ORAdj (95% CI) p
Agonist GnRH Protocol .98 (.89-1.00) .737 0.72 (.85-1.11) .727
Day of embryo transfer - D3 1.91 (1.08-3.39) .025 2.35 (1.27-4.35) .006
Fresh embryo transfer 1.04 (.60-1.81) .879 0.86 (.50-1.48) .596
Endometrial thickness (mm)
<8mm
  8–12
>12
1
1.21 (.40-3.65)
1.16 (.36-3.73)
-
.785
.905
1
1.15 (.38-3.48)
1.06 (.32-3.47)
-
.805
.916
Two or more embryos transferred 2.53 (1.12-5.70) .025 2.26 (1.01-5.21) .050
Embryo classification
  Good Quality
  Poor Quality
  Mixed
1
1.12 (.36-3.45)
.85 (.38-1.89)
-
.837
.704
1
1.25 (.40-3.91)
0.89 (.40-1.91)
-
.692
.778
Age > 37 1.32 (.80-2.18) .269 1.43 (.68-3.01) .339
Endometriosis 1.59 (.9 -2.67) .077 1.60 (.95-2.70) .730
Tubal factor 2.07 (1.25-3.41) .004 2.08 (1.25-3.44) .04
Previous Miscarriage 2.09 (1.02-4.29) .044 1.82 (.87-3.81) .11

OR: odds ratio, ADJ: adjusted, CI: confidence interval, D3: embryos transferred on third day of development, ET: Embryo transfer. Univariate OR and multivariate OR conditional logistic regressions were used to analyze the relationship between the risk factors and ectopic pregnancy. All variables were adjusted in OR adj by female age, year of treatment and number of mature oocytes.