How a Pregnancy is Made: Egg + Sperm = Pregnancy
Note: Euphemisms can be confusing for young people. Often caregivers shy away from using words like sperm and eggs when explaining pregnancy.
Question: How is a baby made?
Validation: What a great question.
Feedback: What do you think?
Listen to the young person's answer. This will help you understand what they are asking if they have misinformation and give you a starting point.
Clarification As Needed: Do you want to know more about your birth story or about how human babies come into the world?
Answer: Use the information that you have gotten to answer just the question that the young person is asking. Do not answer unasked questions. This is a conversation, not a lecture. Allow the young person to ask additional follow-up questions at the moment.
Confirm Understanding: Does that answer your question?
There are two kinds of cells needed to create a pregnancy: male gamete and female gamete.
A sperm (male gamete) is a tiny cell: it is so tiny you can't see just one without special equipment called a microscope. Only one is needed to make a pregnancy. The cell is important because it holds half of the information needed to create the pregnancy.
A human egg (ovum) is also very tiny, but they are the biggest human cell. This female gamete cell holds the other half of the information need to create the pregnancy.
Once the gamete's meet they combine. When this happens the half of the information from each cell combines to make a new larger cell, it is called a zygote.
This is the first step in making a pregnancy.
Note: Personalize the information as needed for your family.
Families may explain that the sperm and egg meet inside of the fallopian tube or in a special glass dish in a doctor's office.
At fertilization, the biological sex of the fetus is determined, depending on whether the egg receives an X or Y chromosome from a sperm cell. If the egg receives an X chromosome, the baby will be born a girl; a Y chromosome means the baby will be born a boy. In some cases, the X & Y aren't clear in the chromosomes and the baby may have some variation on this.
For a pregnancy to begin the zygote needs a place to grow. It grows inside of a uterus. Not everyone has a uterus, so only some people can be pregnant. The pregnancy does not grow inside of a stomach.
A uterus is a special place inside of the body below the stomach. It might look like a baby grows inside of a belly or tummy but it doesn't grow where we swallow food.
Once a zygote gets to the uterus it grows into an embryo.
The embryo is very small and fragile. When everything goes just right the new cell, with half of the information form the male and female gamete, will attach to the wall of the uterus.
Once this phase begins the cells divide and grow. They are combining to make a new unique human.
In the first month of pregnancy, the heart and lungs begin to develop, and the arms, legs, brain, spinal cord and nerves begin to form. Each of these uses information from the male and female gametes that created the pregnancy.
Twins: Sometime the cell will split and make identical twins. Fraternal twins each come from their own egg and sperm.
It takes a lot of time to create a new human. Usually from the moment the sperm and egg meet they need between 32 and 38 weeks inside the uterus growing to be able to be born.
When we talk about a new pregnancy we think about it in weeks.
Note to explain premature birth:
In some places, with the help of a lot of doctors and nurses, a baby can be born at 22-24 weeks. This means that the this only had 18-20 weeks inside the uterus. This mean that the new baby will need a lot of help. They often will stay in the hospital until they are ready, this can be weeks or months.