As you seek to learn ways to help you have a baby, you will run into a lot of scientific details. Knowing the general concept of how a healthy baby is brought to life will help you better understand these details.
Advanced organisms, including us human beings, reproduce by SEXUAL REPRODUCTION. In contrast, simpler organisms, such as bacteria and amoebae reproduce by ASEXUAL REPRODUCTION. Imagine if we reproduced asexually, just like an amoeba. Then, when it came time to make a baby, a piece of ourselves would pinch off and become another organism identical to ourselves. However, that is not the case. We reproduce sexually, meaning it requires two separate organisms (father and mother) to each contribute half of their genetic influence. These come together to make a new person who has a 50/50 combination of the genetics of the two parents. One marvelous advantage of our reproducing this way is the ability to generate nearly infinite diversity. It's the reason that all of us (except for identical twins) are genetically unique.
All babies, including ourselves way back at one time, start out as an embryo. What makes each embryo different is the special genetic information within the DNA. The unique information encoded in our DNA is what regulates our physical features such as eye color, potential height or vulnerability to diabetes.
When a husband and wife set out to create a baby, they each contribute half of their genetic information to create a new person. Each time they do this, they send out a random combination comprising half of the billion bits of genetic information in their DNA. This is the reason that a man and woman can produce a different child each time, rather than having children who are exact replicas of each other.
What are gametes? A human being is composed of many cells. Estimates range from 10 trillion (10 million million) to 100 trillion cells per person. Each of the cells in our bodies contains the same full set of DNA with the exception of sperm cells and egg cells. These are collectively known as gametes and are special in that they only contain half the DNA of other regular cells. The reason they contain half is so that one sperm and one egg can add together to make a fertilized embryo that has a normal full set (half plus half) of genes.
As you and your spouse try to conceive, it may help your understanding to remind yourselves that you are essentially attempting to combine your genetic information by way of your sperm and your eggs. Anything short of one perfect sperm uniting with one perfect egg will fail to produce a healthy baby.
In future posts, we'll learn the important differences between how sperm and eggs function to affect your odds of getting pregnant.