In case you missed it, sperm count has been grabbing global headlines — "Sperm count drop 'could make humans extinct'" blared one news headline — and receiving significant news coverage for the past few months. The attention comes in the wake of alarming findings revealed in a new medical study: Sperm counts have fallen nearly 60 percent among adult men in Europe, North America, Australia and New Zealand in just the past four decades.

The study did not delve into possible causes for the decline, but other studies of male fertility have linked low sperm counts to environmental and lifestyle factors such as exposure to certain chemicals, pesticides and toxins; smoking; alcohol consumption, poor diet and nutrition habits; obesity; stress; heat exposure; and too much time spent watching TV, among others.

A brief overview of sperm

It shouldn't come as a huge surprise that the study attracted so much attention, considering there are millions of couples who are unable to conceive due to sperm-related problems. In fact, more than one in five couples suffer from infertility, and about 40 percent of those infertility cases result from male fertility issues — low sperm count, slow sperm motility (movement) and abnormal sperm morphology (size and shape) top the list of the most common male problems.

Here is an in-depth look at these three medical conditions:

Low sperm count

The World Health Organization (WHO) classifies normal, healthy sperm count as 20 million sperm per one milliliter of semen; a count of 10 million sperm per milliliter or lower is considered low.

During ejaculation, a man with a healthy sperm count releases 60 to 100 million sperm. Conception requires just a single sperm to fertilize the female egg (ovum), and most sperm won't survive the entire journey that begins in the vagina and ends in the fallopian tubes.

Conception is much more difficult when the man suffers from low sperm count. Couples may be able to boost their chances of getting pregnant by timing intercourse for peak fertility days and times. Your doctor or fertility specialist can make specific recommendations based on your individual situation and medical profile.

Slow sperm motility

After low sperm count, slow sperm motility, a condition known as asthenozoospermia or asthenospermia, is the second most common male fertility problem. Sperm motility refers to the movement and swimming of sperm. In men with the condition, sperm move at a much slower speed, and some sperm may have difficulty moving in a forward direction. While healthy sperm swim at a speed of at least 25 micrometers per second, swim speeds may reach only five to ten micrometers per second in men with asthenospermia.

Time is critical to a successful conception. Once the female egg is released, the egg stays viable for only 12 to 14 hours. That's barely enough time for the healthiest sperm to reach the egg, and a nearly impossible obstacle when slow sperm motility is an issue.

Abnormal sperm morphology

The third most common male fertility problem involves sperm of abnormal size and/or shape. Normal, healthy sperm have oval-shaped heads and long tails. In abnormal sperm, the head or tail appears defective; the head may have an unusual shape or be larger than normal, while the most common tail defects are crooked and double tails.

These defects may have an impact on the sperm's ability to reach the egg and penetrate it properly. Bear in mind that it is not uncommon to have a large percentage of sperm that are abnormally shaped. And abnormal morphology doesn't determine whether one is fertile or infertile.

Specialized knowledge and expertise

Most male fertility issues , including the sperm-related conditions discussed above, produce no apparent physical symptoms, so it's important to consult a specialist if you're having trouble conceiving or suspect you may be experiencing a fertility-related problem.

The Fertility & IVF Clinic at Bumrungrad International Hospital features an expert team of doctors and embryologists. The team uses internationally standardized equipment and procedures to diagnose and treat men and women with fertility problems and help couples achieve pregnancy. For more information or to arrange an appointment with a fertility specialist, call +66 2011 2364 or book an appointment online via the Bumrungrad website.