Obese men produced less amount of sperm and had higher levels of abnormalities, which can reduce chances of conceiving and increase the risk of miscarriage. [1]
In the study, doctors examined patient records for 5,316 men attending Aberdeen Fertility Centre between 1990 and 2007. A body mass index (BMI) above 30 is classed as clinically obese. [1]
The study found that obese men produced 60% less seminal fluid than men with a healthy BMI, and had 40% higher levels of abnormal sperm. [1] Other studies have suggested an association between male obesity and increased DNA damage in the sperm, which can be associated with reduced fertility as well. [2]
The mechanism for the relationship could be explained in one or more of the following ways -- different hormone levels in obese men, simple overheating of the testicles caused by excessive fat in the area, poorer semen quality because of lifestyle and diet. [2]
However, the study also found that severely underweight men, i.e. BMIs less than 19, also had poorer sperm quality. [1]
Thus, the newest low-tech fertility treatment may be a diet. Men who are trying for a baby with their partners should first try to achieve an ideal body weight. [2]
Another study of more than 12,000 couples undergoing fertility treatments has found that pregnancy rates drop and miscarriages increase when the father is older than 40. However, how a father's age influences fertility is still unclear.[3]
Fertility specialists suggest in vitro fertilization [IVF] or intracytoplasmic sperm injection (ICSI) — a technique that places sperm directly into an egg — to couples when either partner is over age 40. [3]
Please discuss with your doctor for more information and advice. This article can not be used as medical advice. Reference: [1] Ian Sample Lower fertility in men linked to obesityThe Guardian,Thursday July 10, 2008 [2] Newest fertility treatment may be a diet Thu Jul 10, 2008 4:15am BST [3] Dad's Age Plays Role In Fertility CBS News July 8, 2008