Our analysis found that race/ethnicity is a significant independent predictor of vasectomy utilization in the United States. Compared to white men, blacks and Hispanics are significantly less likely to undergo vasectomy even after accounting for multiple confounding variables. Prior data has shown that race predicted utilization of tubal ligation with higher rates in Hispanic and black women than other races.7,8
Furthermore, other studies have reported lower rates of vasectomy utilization among minority men.1,8,11
However, published data from prior studies has been limited to female partner report and clinic samples. Two studies relied on female partners reporting their partner’s vasectomy status.1,8
Another study queried men undergoing vasectomy at multiple locations by utilizing a questionnaire to identify demographics and motivations for vasectomy but did not provide comparison to a similar population of men not undergoing vasectomy.11
To our knowledge, this is the first population based analysis of vasectomy utilization in U.S. men.
Previous studies had suggested that education level may allow stratification of men who undergo vasectomy;1,11
however, our analyses did not find an association between education level and vasectomy utilization. This could indicate that vasectomy utilization is decided by culture rather than social or economic status. Alternatively, a majority of subjects represented lower educational levels and the data may have been underpowered to detect a difference.
Somewhat intuitively and similar to studies of tubal ligation, male sterilization rates among those ages 30 to 45 increase with marriage, age, and number of children all of which can be associated with relationship stability and successful past fertility.1,7
Bumpass found that prior abortions decreased rates of tubal ligation in women, postulating that women thereafter viewed abortion as a viable option for family planning.1
In men, our own experiences suggested that a failed or unwanted pregnancy may be the impetus for vasectomy. While there was an association between failed pregnancies which ended in miscarriage, abortion, or stillbirth leading to an increase in the rate of vasectomy on bivariate analysis, the association disappeared on multivariate analysis suggesting that other confounding variables may explain this finding.
The explanation for the racial disparity in vasectomy is uncertain. A search for cultural causes such as religion did not yield a significant effect as it did for female tubal ligation where Catholicism was protective.1,7
While insurance status had no association, the access to health care and services or counseling offered may vary by race. Indeed, other groups have shown racial differences in health care both in the NSFG and in other data sets. 12–14
Others have postulated that there may be different racial perceptions of fertility whereby masculinity is closely tied to a man’s ability to father children.15–17
As such, vasectomy may be perceived as emasculating in certain cultures.
Indeed, it is crucial that providers adequately counsel patients about all reproductive options and ensure proper understanding of the true risks, benefits and alternatives of vasectomy. Examination of men who father a child after vasectomy may suggest instances of poor patient - provider communication. The majority (56.3%, 9/16) had a child within six months of their vasectomy. However, there is also a group of 4 men who had a child nine to twelve months after vasectomy. This group may represent those who had an unintended pregnancy by having unprotected intercourse while motile sperm remained in their ejaculate.18,19
The literature suggests that approximately three months are required for the motile sperm count to reach zero, and it should be confirmed with a semen analysis prior to unprotected intercourse. By our analysis, men who underwent vasectomy had a 10 fold lower rate of condom use compared to their counterparts. Men must be properly educated to continue to use protection until sterility can be assured after vasectomy. Even with time, there is a failure rate to vasectomy with unintended pregnancies occurring at a rate of 0.1%.20,21
Among men surveyed by the NSFG, two men had a child over two years from the time of their vasectomy, however, this must be interpreted with caution as the circumstances of these pregnancies cannot be ascertained.
Additional limitations of this study merit mention. The NSFG is a cross sectional study which surveys participants at a single point in time often several years after the vasectomy. While race will remain constant, other variables such as educational level or income could conceivably change with time. In addition, certain variables (e.g. income) could be incorrectly reported by participants. Such misreporting would likely occur randomly leading to a regression to the mean and favor the null hypothesis. Despite this, income remained a significant predictor of vasectomy. Lastly, the low number of Asian men in this sample preclude accurate analysis of factors associated with vasectomy in this population.