Impact of men's dairy intake on assisted reproductive technology outcomes among couples attending a fertility clinic.

Intake of full-fat dairy has been linked to lower semen quality but whether this leads to decreased fertility is unknown. To address this question, we prospectively evaluated the association of men's dairy intake with treatment outcomes of subfertile couples undergoing assisted reproductive technology (ART). We followed 142 men from couples undergoing infertility treatment with ART at an academic fertility centre between 2007 and 2014. Couples completed dietary assessments prior to treatment, and the female partners underwent a total of 248 ART cycles. Multivariable generalized linear mixed models were used to examine the association of dairy intake with fertilization, implantation, clinical pregnancy and live birth rates adjusting for age, body mass index, smoking status, total exercise time, dietary patterns, alcohol, caffeine, total energy intake, and female dairy intake. Intake of dairy foods, regardless of their fat content, was not associated with fertilization, implantation, clinical pregnancy or live birth rates. The adjusted live birth rates (95% confidence interval) for couples in increasing quartiles of men's dairy intake were 0.42 (0.25, 0.60), 0.25 (0.13, 0.42), 0.26 (0.15, 0.41), and 0.44 (0.27, 0.63) (p linear trend = 0.73). Results remained similar after adjustment for female partner intake of dairy foods. Overall, men's dairy intake was not associated with treatment outcomes of couples undergoing ART.