Summary of “Vasectomy Reversal Semen Analysis: New Reference Ranges Predict Pregnancy”

***Trost Commentary and Key Take-Home Points***

This is one of the most helpful and impactful manuscripts currently available relating to vasectomy reversals in my opinion.  It is also one of the manuscripts that we refer to most often for patients post-operatively.  The main reason for this importance is because it helps to define numbers which are predictive of pregnancy post-operatively.  Specifically, how likely are you to get pregnant if you have a specific sperm concentration, motility, or morphology result?  The limitations with the manuscript are small numbers (only 139 men) and the exclusion of men who had unknown pregnancy outcomes or those who used assisted techniques (significantly overinflates the actual pregnancy rate).  It also only considers pregnancies among people who achieved a pregnancy in the first 18 months.  In other words, if you had a pregnancy at month 19, you would not be considered to have had a pregnancy in the current study.  So, these limitations hurt the study a bit (and undermine the reliability of findings a little), but it is still one of the most helpful studies of its kind out there as it provides specific thresholds for increasing the likelihood for a successful pregnancy. 


Vasectomy is a common method of contraception, though 6% of men who undergo vasectomies end up requesting a reversal. Some of the reasons for choosing a reversal could be a new partner, desire for more children, death of a child, etc. Several factors affect vasal patency including obstructive interval, vasal fluid characters and type of surgical procedure. The majority of studies done on the effectiveness of vasectomy reversals have tested the return of sperm to the ejaculate, while few address the rate of pregnancy following the reversal. 

Materials and Methods

The current study included 139 men with vasectomy reversals who had a known spontaneous pregnancy and excluded men with unknown pregnancy outcomes or who used assisted reproduction to attain a pregnancy. There were 2 groups of patients, group 1 were men who had a spontaneous pregnancy within 18 months of the reversal and group 2 were men who did not have a spontaneous pregnancy within 18 months. 

Vasectomy reversal surgeries were performed as either a formal two-layer or modified one-layer reconstruction. A vasoepididymostomy (VE) was performed on men where no sperm or sperm parts appeared in the vasal effluent fluid. Patients underwent either bilateral vasovasectomy (VV), unilateral VV/VE, bilateral VE, unilateral VV or unilateral VE. A semen analysis was done 6 weeks post-operatively and patients were stratified based on semen volume, sperm concentration, total motility and normal strict morphology. 


For the 139 men in the study the overall patency rate was 91.8% and 49.6% achieved a spontaneous pregnancy within 18 months. The pregnancy outcome was significantly affected by the type of surgery performed, with the highest rate of success after bilateral VV. The presence of sperm or sperm parts was also significant 95.6% of men in group 1 had sperm or sperm parts while this was the case in only 65.7% of group 2. Additionally, group 1 also showed significantly higher sperm concentration, total motility, total motile concentration and normal morphology. 


While semen analysis is the standard evaluation for male fertility, it is limited in its ability to accurately predict pregnancy rates. Our findings show a much lower semen parameter value is needed to cause a spontaneous pregnancy than the WHO had originally specified. This makes vasectomy reversal an effective, safe and affordable option for those who desire more children. Some other studies done on this topic have similarly shown that the pregnancy rates are significantly influenced by obstructive interval, vasal fluid sperm quality, while other studies have seen less correlation. 

Data from this study shows a significant difference in efficacy depending on the type of vasectomy reversal performed. Bilateral VV had the highest success rates, and little difference was seen between formal two-layer or modified one-layer techniques. 


Despite the small sample size and short follow up time, this study validates the efficacy and safety of vasectomy reversals and stimulates further investigation into the appropriate reference ranges of semen analysis.   


Majzoub A, Tadros NN, Polackwich AS, Sharma R, Agarwal A, Sabanegh E Jr. Vasectomy reversal semen analysis: new reference ranges predict pregnancy. Fertil Steril. 2017 Apr;107(4):911-915. doi: 10.1016/j.fertnstert.2017.01.018. Epub 2017 Mar 7. PMID: 28283266.

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