Does alcohol consumption affect the outcome of Frozen Embryo Transfer (FET) in adults of reproductive age?

Does Alcohol Affect Frozen Embryo Transfer (FET) Outcomes?

Yes, alcohol consumption negatively impacts FET and all assisted reproductive technology outcomes, and couples should abstain from alcohol prior to and during fertility treatment procedures.

Evidence for Alcohol's Impact on Fertility Treatment

Female Alcohol Consumption Effects

Alcohol consumption by women undergoing assisted reproductive technology significantly reduces success rates across multiple parameters:

• Women consuming alcohol experience a 13% decrease in the number of eggs retrieved for each additional drink per day consumed in the year before IVF/GAMETE procedures 1

• The risk of IVF failure increases 4.14-fold with alcohol intake of 12 grams/day during the week before treatment, and 2.86-fold during the month before 2

• Women drinking at least 4 drinks per week have a 16% lower live birth rate (OR 0.84) compared to those drinking fewer than 4 drinks weekly 2

• The risk of not achieving pregnancy increases 2.86 times when women consume alcohol 1 month prior to the procedure 1

• Miscarriage risk increases 2.21 times when alcohol is consumed 1 week before the IVF/GAMETE procedure 1

Male Alcohol Consumption Effects

Paternal alcohol use also significantly impairs fertility treatment outcomes:

• Men consuming one additional drink per day increase the risk of not achieving a live birth by 2.28 to 8.32 times, depending on timing relative to the procedure 1

• Beer consumption specifically affects live births with odds ratios ranging from 5.49 to 45.64 times increased risk 1

• Male alcohol consumption increases miscarriage risk by 2.70 to 38.04 times when consumed ≤1 month before and during IVF/GAMETE procedures 1

Embryo Quality Impact

Alcohol consumption directly compromises embryo quality:

• Women who consume alcohol produce significantly more Class B embryos (86.96%) compared to Class A embryos (4.35%) 3

• A statistically significant relationship exists between the amount of alcohol consumed and embryo class quality (p=0.005) 3

• Women consuming >25 grams of ethyl alcohol daily produce 72.72% Class B embryos, compared to 44.44% in sporadic drinkers and 30% in abstainers 3

Guideline-Based Recommendations

Preconception Counseling

All women of reproductive age undergoing fertility treatment should be screened for alcohol use:

• The European Association for the Study of the Liver recommends that pregnant women should be screened for alcohol use and referred for management when appropriate 4

• For women with alcohol-related conditions, delaying conception until abstinence is achieved is strongly recommended 4

• Alcohol use in pregnancy is strongly associated with increased risk of preterm birth and small for gestational age infants 4

Clinical Implications for FET Specifically

While the provided evidence primarily addresses fresh IVF cycles, the biological mechanisms apply equally to FET:

• Alcohol affects ovarian function through disruption of the hypothalamic-pituitary axis, leading to anovulation and hormonal imbalances that persist beyond acute consumption 4

• Excess alcohol intake directly affects ovarian function independent of liver disease 4

• The endometrial receptivity and implantation environment are compromised by alcohol's effects on estrogen metabolism and hormonal regulation 4

Practical Clinical Algorithm

For Women Undergoing FET:

1. Screen all patients for alcohol consumption using validated tools before initiating FET cycles 4

2. Counsel complete abstinence starting at least 1 month before the FET cycle (ideally longer given the 2.86-fold increased failure risk with consumption 1 month prior) 2, 1

3. Maintain abstinence through the FET procedure and early pregnancy period given the 2.21-fold increased miscarriage risk 1

For Male Partners:

1. Counsel complete abstinence for at least 1 month before the FET cycle 1

2. Emphasize that male alcohol consumption affects outcomes independently of female consumption 1

Critical Caveats

The evidence shows dose-dependent effects, but no safe threshold has been established:

• One large Danish cohort study 5 found no significant association between low-to-moderate alcohol intake and IVF outcomes, but this contradicts multiple other studies showing harm even at low levels 2, 1, 3

• The Danish study acknowledged potential for non-differential exposure misclassification and confounding 5

• Given the conflicting evidence and the established biological mechanisms of harm, the safest recommendation remains complete abstinence 2, 1

Brief interventions can reduce alcohol consumption:

• Randomized controlled trials show that brief interventions significantly decrease drinks per drinking day among at-risk drinkers undergoing IVF 6

• Both brief intervention and assessment-only approaches contribute to decreased alcohol use 6

Bottom Line for Clinical Practice

Advise all couples undergoing FET to completely abstain from alcohol for at least 1 month before the procedure and throughout early pregnancy. The evidence demonstrates clear harm from both maternal and paternal alcohol consumption on egg quality, fertilization rates, embryo quality, implantation, pregnancy achievement, and live birth rates 2, 1, 3. While one study suggested low-to-moderate consumption may be safe 5, the preponderance of evidence and biological plausibility support complete abstinence as the standard of care 2, 1, 3.