Joint impacts of cadmium exposure and anxiety on in vitro fertilization outcomes: a couple-based cohort study.

BACKGROUND

Accumulating evidence indicates that cadmium (Cd) and anxiety independently impair early embryonic development. However, the potential joint impact of these two factors on early IVF outcomes remains unclear.

METHODS

This prospective couple-based cohort study investigated the association of plasma Cd and anxiety with early IVF outcomes among 549 couples. Plasma Cd concentrations (μg/L) were measured by inductively coupled plasma mass spectrometry. Anxiety levels were evaluated with the Generalized Anxiety Disorder 7-item scale. We examined the independent and combined effects of Cd exposure and anxiety on early IVF outcomes using linear (fertilization rate and blastocyst formation rate) and Poisson (number of oocytes retrieved and high-quality embryos) regression in both individual-specific and couple-based analyses.

RESULTS

After adjusting for confounders, individual-specific analyses showed that male Cd exposure alone was associated with reductions in both the number of oocytes retrieved (percent change: -8.61%; 95% CI: -14.88, -1.88) and high-quality embryos (percent change: -13.59%; 95% CI: -24.76, -0.81). Moreover, the combined Cd/anxiety exposure demonstrated more pronounced adverse effects on the number of oocytes retrieved (percent change: -9.95%; 95% CI: -16.44, -2.98) and high-quality embryos (percent change: -16.46%; 95% CI: -27.90, -3.32) than Cd exposure alone. A lower blastocyst formation rate was also observed with combined exposure in both women (β = -0.08, 95% CI: -0.15, -0.01) and men (β = -0.07, 95% CI: -0.14, 0.00). Couple-based analyses confirmed stronger joint reductions in oocytes retrieved (percent change: -10.70%; 95% CI: -19.21, -1.30) and high-quality embryos (percent change: -20.81%; 95% CI: -35.35, -3.16), as well as the blastocyst formation rate (β = -0.11; 95% CI: -0.21, -0.02).

CONCLUSION

These findings suggest that Cd exposure and anxiety may jointly impair early IVF outcomes, particularly reducing the number of oocytes retrieved and high-quality embryos.