Thinking about starting a family? A little common sense coupled with an ounce or two of prevention can go a long way in having a healthy child.

Once you and your partner decide you're ready to be parents, you probably want to get the baby show on the road right away. Many couples are surprised when it takes them six months or more to conceive; after all, haven't we spent most of our reproductive lives trying not to reproduce?

For couples actively seeking pregnancy, the average time to conception is about 8-9 months for couples where the woman is under age 35, says Dr. Matan Yemini, co-director of the Diamond Institute for Infertility and Menopause in Millburn, NJ. If the woman is older, it can take even longer.

But fertility, or a lack thereof, does not rest only with the woman. You and your partner both have important roles to play. You will, after all, contribute half of your child's chromosomes. Indeed, it is your sexual chromosome make-up—XY—that determines the sex of the baby.

There are things you can do to increase both your chances of conception and your odds of having a healthy baby.

How It All Works

Let's take a brief look at what's involved in the story of "Sperm Meets Egg."

Here's the short version: The male's sperm must navigate through the female's cervical mucus (now receptive at ovulation to the sperm), travel the length of the uterus, and enter the fallopian tubes.

"Once in the fallopian tube, sperm must meet an egg, penetrate the egg's protective coating and inner membrane, and finally, fertilize the egg," according to the Atlanta Reproductive Health Centre (ARHC).

When you take into account that the female releases only one egg per month or so, the sperm's Herculean task makes your old problem of finding a Saturday night date look easy. In fact, the ARHC notes, "Human conception is a difficult and complex process, even under the best conditions." Your job, then, is to get your sperm ready for the journey of a lifetime.

What To Watch

"Being well is probably the most important thing," says Yemini. "Anything that will devastate your body or normal function will also have an effect on reproduction." In other words, your reproductive system is only as healthy as the rest of your body.

This means all the usual suspects need to go. Recreational drugs, like ]]>cocaine]]> and marijuana, and anabolic steroids can reduce sperm counts, reports Ann Douglas, author of The Unofficial Guide to Having a Baby . While men don't need to abstain from alcohol completely, " ]]>Heavy drinking]]> , in the long run, can affect hormone levels and liver function and affect conception," says Yemini.

Toss the cigarettes, too. ]]>Smoking]]> not only affects sperm production, but can also has a negative impact on the developing fetus—and the baby after it's born. ]]>Quitting]]> "may also make it easier for [your] partner to quit smoking, something that's very important," says Douglas.

If you are significantly overweight, ]]>lose some body mass]]> . According to Douglas, if you are overweight your body may produce an abundance of the female sex hormone estrogen, and this could lead to fertility problems. She also suggests avoiding exposure to substances that could be harmful to sperm.

"Toxic chemicals and radiation can potentially damage sperm production, leaving a man incapable of fertilizing an egg, or permanently damaging his genetic material."

The bottom line: When it comes to health, use common sense. If it's bad for you, it's most likely bad for your baby-to-be.

Hidden Factors

Common sense will take you only so far, though. There are a few fertility factors of which you might be unaware. Yemeni and Douglas both caution against extended use of saunas and hot tubs, as excessive heat can interfere with sperm production. Again, you don't have to stay away completely; just limit your use.

Some medications can also affect reproductive ability. According to Douglas, certain antibiotics, cimetidine (an antacid), and ]]>chemotherapeutic agents]]> can reduce sperm counts, and some blood pressure drugs can cause ejaculatory dysfunction. Talk with your doctor or pharmacist to determine if any medications you're taking may have unwanted side effects. Some men who know they are about to undergo chemotherapy elect to have their sperm frozen before the treatment regimen begins.

Too Much of a Good Thing

You might think that one of the best things you can do to get in shape is to exercise. And when it comes to exercise, more is better, right? Well, it depends.

First, take a look at what types of exercise you're doing. If you're involved in a sport that puts your genitals at risk—such as soccer, rugby, or football—make sure you wear proper protective gear. If you do get injured, seek medical attention immediately, as genital injuries can be very serious.

There's also evidence that other sports, such as bicycling, can curtail your sperm production.

"There was some hint about potential problems from bicycle riding," says Yemini. However, he feels that if your sperm production is normal, bicycling won't hurt.

The Biological Clock

It's true that the woman's age affects both a couple's ability to conceive and the health of the baby. Yemini notes that it's much easier, physically speaking, for a male to be a father when he's 60 than for a woman to become a mother later in life.

However, the man's age is still a factor. "The older the couple, the more chance of malformation," reports Yemini. He says that in the situations where a malformation is discovered via ]]>amniocentesis]]> (a procedure where a portion of the amniotic fluid is analyzed for potential problems), approximately 20% of the time the problem can be attributed to the sperm.

Amniocentesis tests are routinely recommended if the woman is over 35 years old. However, Yemeni says that if the father is over 50 years of age, an amniocentesis should be performed, regardless of the age of the mother.

Healthy Habits for Life

Speaking of age, treating yourself well now will pay off down the road. You're going to want to keep up your healthy habits for a long while to come.

"Becoming a parent is a responsibility," reminds Yemeni, who says good health isn't just for the short term. "Even a 36-year-old lawyer needs healthy parents."