Skip to main content

Table 3 Decomposition of the total effect of ART on the odds of TOF into a direct effect and indirect effect mediated through multiple pregnancies

From: Assessing the role of multiple pregnancies in the association between tetralogy of Fallot and assisted reproductive techniques: a path-analysis approach

Art Total effect Direct effect Indirect effect Estimated size of the indirect effect
  Unadjusted OR* 95% CI Adjusted§ OR* 95% CI Unadjusted OR* 95% CI Adjusted OR* 95% CI Unadjusted OR* 95% CI Adjusted OR* 95% CI  
None 1.0 ref. 1.0 ref. 1.0 ref. 1.0 ref. 1.0 ref. 1.0 ref.  
All methods combined 1.9 1.2 – 3.1 2.6 1.5 – 4.5 1.7 1.0 – 2.8 2.1 1.2 – 3.7 1.1 1.0 – 1.4 1.2 1.0 – 1.5 20.9%
IO$ only 1.4 0.7 – 2.9 2.1 1.0 – 4.7 1.3 0.7 – 2.6 1.8 0.9 – 3.9 1.1 1.0 – 1.2 1.2 1.0 – 1.3 19.1%
IVF£ only 2.2 1.0 – 4.7 2.8 1.2 – 6.7 1.8 0.8 – 3.8 2.1 0.9 – 5.2 1.2 0.9 – 1.6 1.3 1.1 – 1.7 27.8%
IVF+ICSI¥ 3.1 1.0 – 10.0 3.5 1.1 – 11.2 2.8 0.9 – 8.9 3.1 0.9 – 10.1 1.1 1.0 – 1.3 1.1 0.9 – 1.4 11.1%
IVF +/- ICSI 2.4 1.3 – 4.6 3.0 1.6 – 5.8 2.1 1.0 – 4.3 2.4 1.2 – 4.6 1.2 0.9 – 1.5 1.3 1.0 – 1.6 22.3%
  1. *Odds ratios (OR) represent the odds of a birth (including live births, stillbirths and pregnancy terminations) with TOF (cases) relative to the odds of a birth with one of the malformed controls (club-foot, angioma, skin abnormality, polydactyly, syndactyly, and congenital hip dislocation).
  2. §Adjustment was made for maternal age, occupation, geographic origin, paternal age and year of birth.
  3. $Inductors of ovulation.
  4. £In vitro fertilization.
  5. ¥IVF with intracytoplasmic sperm injection.