Perinatal Risks Associated with Early Vanishing Twin Syndrome following Transfer of Cleavage- or Blastocyst-Stage Embryos

Table 7

Term low birth weight and multiple logistic regression to account for confounding variables.

Term LBW	Standard error	Adjusted OR; (95% CI)	P
Age (<35 versus ≥35 years)	0.46	0.86 (0.59–7.80)	0.76
Duration of ovarian stimulation (<9 versus ≥9 days)	0.73	0.92 (0.35–3.08)	0.33
Gonadotropin dose (<2000 versus ≥2000 IU)	0.42	0.83 (0.44–6.09)	0.38
Peak E2 level (<2000 versus ≥2000 pg/Ml)	0.32	0.92 (0.16–1.86)	0.48
Total number of oocytes (<10 versus ≥10)	0.39	0.94 (0.09–1.82)	0.25
Blastocyst-stage ET (yes versus no)	0.47	0.91 (0.28–3.83)	0.84

LBW: low birth weight; E₂: estradiol; ET: embryo transfer.