AUTHORS:  Hammoud AO, Wilde N, Gibson M, Parks A, Carrell DT, and Meikle AW.
PLACE OF STUDY:  University of Utah School of Medicine
PUBLICATION:  Fertility and Sterility
PUBLICATION DATE:  December 2008
ABSTRACT:

BACKGROUND:  To study the effect of male obesity on sperm parameters and erectile dysfunction.  METHODS:  Body Mass Index (BMI) was divided into 3 groups:  normal (BMI<25 kg/m2), overweight (25 kg/m2 ≤BMI<30 kg/m2), and obese (BMI≥30 kg/m2).  Sperm parameters were evaluated in the 3 weight status groups.  RESULTS:  The prevalence of oligozoospermia (low sperm count) and prevalence of low progressive motile sperm count both increased with increasing BMI.  The incidence of erectile dysfunction did not vary across BMI categories.  CONCLUSIONS:  Male obesity is associated with increased incidence of low sperm concentration and low sperm progressive motility.

EXPLANATION AND SUMMARY OF FINDINGS:

Body mass index (BMI) is a measure of a person’s weight status.  BMI is calculated using a person’s weight and height [weight (in kilograms)/height (in meters)2].  The BMI number obtained (see link to BMI calculator below), determines if a given person is in the underweight, normal weight, overweight, obese, or morbidly obese category.  As a premise to the study, the authors point out that there is recent and rapid increase in the prevalence of obesity in the developed world.  Furthermore, the authors state that male obesity has been shown to disturb the hormonal milieu in men leading to a decrease in levels of testosterone and an increase in level of estrogen, which can lead to decreased sperm production.  In order to examine the effect of weight status on sperm parameters, the authors evaluated semen analyses from 390 men (average age = 32.8 years).  Men were categorized as normal weight, overweight, or obese based on their BMI (see abstract above).  Semen parameters were compared among the three weight status groups.  The prevalence of oligozoospermia (low sperm count=sperm concentration of < 20 million sperm/ml) increased from 5.3% in the normal weight group, to 9.5% in overweight patients, to 15.6% in obese patients.  The prevalence of low progressive motile sperm count (defined as < 5 million progressively motile sperm per ejaculate) increased from 3.2% in normal weight patients, to 6.5% in overweight patients, to 10.9% in obese patients.  The authors concluded that there is a strong negative relationship between increasing weight status and altered sperm parameters which may translate into male factor infertility.

 WHAT DR. MOR THINKS:  
   
Maintaining a balanced healthy lifestyle is important.  Routine exercise, combined with a balanced diet, is essential for your general and reproductive health.  If you can, strive towards a normal BMI (18.5-24.9).  In couples who plan to have a child where the male partner is overweight or obese, the findings of the above study suggest that it would be reasonable to obtain a semen analysis early on in the process.  If the semen analysis is minimally to moderately abnormal, and the couple has not been able to conceive for several months, an intrauterine insemination may be helpful.

The findings of the above study must be interoperated with caution.  Being a male who is overweight or obese does not necessarily suggest infertility.  However, it may suggest that an overweight or obese weight status is a risk factor for male factor infertility.      

The California Center for Reproductive Health can help you in achieving your weight and reproductive goals.  We specialize in evaluation and treatment of male factor infertility.  Please contact us for additional information.