also cause nausea, diarrhea, and exhaustion, just to make you feel really terrible during your periods. Taking anti-inflammatory medications such as ibuprofen can help with the symptoms.
Hanging Out with the Guys
Compared to women, guys let it all hang out, reproductively speaking. The external male reproductive organs include the penis, scrotum, and the testicles. Take a look at what every guy should have. See Figure 2-2 for a graphic portrayal of your average man.
Illustration by Kathryn Born
FIGURE 2-2: The male reproductive organs.
The penis
The number-one guy concern is probably related to penis size: How do I compare to everyone else? For those obsessed, here are the standards: normal length when flaccid, or limp, 3.9 inches; stretched (still limp), 4.8 inches; erect, 5 to 7 inches, with an average erect size of 5.1 inches. We hope that bit of info made most of you fellows feel better. A small penis, less than 1.9 inches limp, is usually able to impregnate as long as it can get the sperm into the vagina, up toward the cervix. Size is rarely an issue in infertility.
Size may not matter, but function does. If you have seen commercials for erectile dysfunction (ED), you may be comforted to know that even athletes and famous men have problems with erectile dysfunction (ED), also known as impotence. As nice as it is to know that you’re not alone, this condition can be an embarrassing detriment to getting pregnant. Impotence, the inability to have or sustain an erection, is more common as men get older; as many as 50 percent of men between the ages of 40 and 70 have had problems with impotence. Impotence can be caused by diseases such as diabetes or by chronic conditions, such as alcohol abuse, or it can be a side effect of medications. (We discuss impotence in Chapter 12.) ED can be a problem that occurs as patients move through treatment for infertility. Performance anxiety and the sterile nature of fertility treatments may cause ED. Adjusting the environment or using frozen sperm specimens collected under less stressful conditions can help reduce ED.
The testicles
Testicles are the sperm production and warehouse site. Here, as in many other places on the human body, nature has been generous and given two of the same body part (testicles, in this instance), in case something happens to one. Testicles first develop inside the abdomen and gradually descend outside the body by the time a baby boy is born. At birth, about 4 in 100 boys have undescended testicles, properly called cryptorchidism. Testicles need to be kept a few degrees cooler than 98 degrees for sperm to develop properly, so to prevent future infertility, doctors usually recommend surgery to lower the testicles outside the body as soon as the baby is a year old.
The testicles are contained in a pouch of skin called the scrotum. In about 80 percent of men, the left testicle is bigger and hangs lower. Sometimes the scrotum is abnormally large, which can be caused by a hydrocele (a collection of fluid inside the scrotum), or by a varicocele (dilated or varicose veins in the scrotum). These conditions can be surgically corrected. If left alone, they can raise the temperature of the testes and may cause infertility.
Sperm — 200 million of them!
Nature designed women to have one child at a time — which is why most women will release a single egg every month. The eggs enter the fallopian tube. The tube has a very special environment designed to meet the metabolic needs of the egg and the early developing embryo. The tube also has cells with hair-like projections so that the egg and then the embryo can be transported to the uterus. Sperm fertilize the egg in the fallopian tube. A normal ejaculate may contain over 100 million sperm, but only about 100–1,000 actually make it to the egg. The sperm have proteins on their surface that match proteins on the shell of the egg and allow the sperm to bind to the shell of the egg. The sperm do not mechanically pierce the egg; they release proteins that biochemically digest a pathway through the shell, and once near the egg, bind to the egg. The egg then brings the sperm inside. There are packages of proteins just inside the wall of the egg that are released once a sperm enters. They harden the shell and prevent fertilization by more than one sperm. The fertilized egg is now called an embryo and will grow to an 8-32 cell embryo in the fallopian tube before being transported to the uterus.
Why are there so many more sperm than eggs? Because it’s a long way through the uterus and up the tubes, and because only 50 percent (of a good sperm sample) of the sperm know how to swim forward, and because some of them are barely moving, a tremendous number of sperm are needed to ensure that a few hundred will get through to the egg. Their journey is like one of you trying to swim across the Pacific Ocean. If there were 200 million of you, maybe a few hundred would make it. Imagine if you had to fertilize an egg when you finally got there! (We talk about sperm and male factor issues much more in Chapter 12.)
Putting Male and Female Parts Together
Now that you know how all your parts work, are you ready to have a baby? Yes? Then it’s time to have sex. No, not right now. (Well, okay, if you must, but proper timing will enhance the chance for pregnancy.) So it is important to have sex when the timing is right. How do you know when the timing is right? This is more than just mood lighting and foreplay. To get pregnant, you need to be close to ovulation.
Recognizing signs of ovulation
It normally takes between 10 and 14 days to mature a good egg and release it, so if you have 28- to 30-day cycles, you may ovulate sometime between day 14 and day 16 of your cycle. Shorter cycles have an earlier ovulation day, and longer cycles a later ovulation day. How do you know if you’ve ovulated? Some women experience a sharp pain when they ovulate, called mittelschmertz, or have a vaginal discharge; however, these symptoms are very subjective and are not reliable indicators of ovulation. A more reliable method is correctly using
