Within 24 hours after fertilization, the egg that will become your baby rapidly divides into many cells . By the 8th week of pregnancy, the embryo develops into a fetus. There are about 40 weeks to a typical pregnancy. These weeks are divided into three trimesters.
When does a pregnancy start?
The start of pregnancy is actually the first day of your last menstrual period. This is called the gestational age, or menstrual age. It’s about 2 weeks ahead of when conception actually occurs. Though it may seem strange, the date of the first day of your last period will be an important date when determining your due date . your Healthcare provider will ask you about this date and will use it to figure out how far along you are in your pregnancy.
How does conception work?
Each month, your body goes through a reproductive cycle that can end in one of two ways. You will either have a menstrual period or become pregnant. This cycle is continuously happening during your reproductive years- from puberty in your teen years to menopause around age 50.
In a cycle that ends with pregnancy, there are several steps. First, a group of eggs ( called oocytes) gets ready to leave the ovary for ovulation( release of the egg). The eggs develop in small, fluid – filled cysts called follicles. Think of these follicles as small containers for each immature egg. Out of this group of eggs, one will become mature and continue on through the cycle. This follicle then suppresses all the other follicles in the group. The Other follicles stop growing at this point.
The mature follicle now opens and releases the egg from the ovary. This is ovulation. Ovulation generally happens about 2 weeks before your next menstrual period begins. It’s generally in the middle of your cycle.
After ovulation, the opened( ruptured) follicle develops into a structure called the Corpus luteum. This secretes (releases) the hormones progesterone and estrogen. Progesterone helps prepare the endometrium( lining of the uterus). This lining is the place where a fertilized egg settles to develop . If you don’t become pregnant during a cycle ,this lining is what is shed during your period.
On average, fertilization happens about 2 weeks after your last menstrual period. When the sperm penetrates the eggs, changes occur in the protein coating of the egg to prevent other sperm from entering.
At the moment of fertilization, your baby’s genetic make-up is complete, including its sex. The gender of your baby depends on what sperm fertilizes the egg at the moment of conception. Generally ,women have a genetic combination of XX and men have XY. Women provide each egg with an X. Each sperm can be either an x or y. If the fertilized egg and sperm is a combination of anX and Y, its a boy. If there are 2 Xs, it’s a girl.
What happens right after conception?
With in 24 hours after fertilization, the egg begins rapidly dividing into many cells. It remains in the fallopian tube for about three days after conception. Then the fertilized egg (now called a blastocyte) continues to divide as it passes slowly through the fallopian tube to the uterus. Once there, its next job is to attach to the endometrium. This is called implantation.
Before implantation though, the blastocyte breaks out of its protective covering. When the blastocyte makes contact with the endometrium, the 2 exchange hormones to help the blastocyte attach. Some women notice spotting( slight bleeding) during the one or 2 days when implantation happens . This is normal and is not something you should worry about. At this point, the endometrium becomes thicker and the cervix (the opening between your uterus and birth Canal ) is sealed by a plug of mucus . Within 3 weeks, the blastocyte cells ultimately form a little ball, or an embryo . By this time, the first Nerve cells have formed.
Your developing fetus has already gone through a few name changes in the first few weeks of pregnancy. Generally, it’s called an embryo from conception until the 8th week of development . After the 8 week, it’s called a fetus until it’s born.
How early can I know I am pregnant?
From the moment of conception, the hormone human chorionic gonadotropin ( hCG ) will be present in your blood. This hormone is created by the cells that form the Placenta (food source for the growing foetus ). It’s also the hormone detected in a pregnancy test. Even though this hormone is there from the beginning, it takes time for it to build within your body. It typically takes three to four weeks from the first day of your last period for the HCG to increase enough to be detected by pregnancy test.
When should I reach out to my health care provider about a new pregnancy?
Most Healthcare providers will have you wait to come in for an appointment until you have had a positive home pregnancy test. These tests are very accurate once you have enough hCG circulating throughout your body. This can be a few weeks after conceptions. It’s best to call your health care provider once you have a positive pregnancy test to schedule your first appointment.
When you call, your Healthcare provider may ask you if you are taking a prenatal vitamin. These supplements contain Folic acid . It’s important that you get a at least 400 mcg of Folic acid each day during a pregnancy to make sure the fetus’s neural tube( beginning of the brain and spine) develops correctly. Many Healthcare providers suggest that you take prenatal Vitamins with Folic acid even when you are not pregnant . If you were not taking prenatal vitamins before your pregnancy, your provider may ask you to start as early as possible.
What’s the timeline for fetal development?
The foetus will change a lot throughout a typical pregnancy. This time is divided into three stages, called trimesters. Each trimester is a set of about three months. your Healthcare provider will probably talk to you about fetal development in terms of weeks. So, if you are 3 months pregnancy, you are about 12 weeks. you will see distinct changes in the foetus, and yourself, during each trimester.
Traditionally, we think of a pregnancy as a 9 month process . However, this is not always the case. A full term pregnancy is 40 weeks, or 280 days. Depending on what months you are pregnant during( some are shorter and some longer )and what week you deliver, you could be pregnant for either nine months or 10 months. This is completely normal and healthy.
Once you get close to the end of your pregnancy ,There are several category names you might hear regarding when you go into labour. These labels divide up the last few weeks of pregnancy. They are also used to look out for certain complications in newborns. Babies that are born in the early term period or before may have a higher risk of breathing, hearing or learning issues than babies born a few weeks later in the full term time frame. when you are looking at these levels, it is important to know how they are written. you may see the week first (38) and then you will see two numbers separated by a slash Mark( 6 / 7). This stands for how many days you currently are in the gestational week . So, if you see 38 6 / 7, it means that you are on day 6 hour of your 38 week .
The last few weeks of pregnancy are divided into the following groups:
- Early term : 37 0 / 7 weeks through 38 6 / 7 weeks.
- Full term : 39 0/ 7 weeks through 40 6 / 7 weeks.
- Later term : 41 0 / 7 weeks through 41 6 / 7 weeks .
- Post term : 42 0 / 7 weeks and on.
Talk to your Healthcare provider about any questions you may have about gestational age and due date.
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