A zygote inherits one sex chromosome, the X chromosome, from the egg. It also inherits a sex chromosome from the sperm. This may be either an X or Y chromosome. If the sperm contained an X chromosome, the fetus will be female XX. If the sperm contained a Y chromosome, the fetus will be male XY. At 3 weeks pregnant, the fertilized egg, or zygote, measures 0. The zygote will spend several days making its way down the fallopian tube.
During this time, it develops into a morula, a ball of 12—15 cells. As time goes on, it will become a bigger collection of cells called a blastocyst.
At week 4 , the blastocyst implants into the wall of the uterus. The blastocyst contains an inner and an outer part. The inner part will ultimately develop into the embryo. The outer part will become the placenta, an outer shell that will provide protection and nourishment to the growing embryo.
At this point, the baby is a cluster of cells measuring approximately 0. Around the beginning of week 5 , doctors will likely start referring to the baby as an embryo, and it will be about the size of a sesame seed. You may need to take a break from strenuous exercise during pregnancy, and a doctor can help modify or develop a healthful exercise plan. During the first 6 weeks of pregnancy, there may be no indications of pregnancy.
This means the implantation takes place about 7 to 8 days after fertilization of the egg. The time required for implantation in both the cases, normal pregnancy and pregnancy through IVF, is more or less the same.
How long does it take for the embryo to implant in the uterus? Here is a step by step guide: When you engage in unprotected sex, sperm passes through the vagina and get past the cervix to reach up to the fallopian tubes. Here, a sperm is most likely to combine with an egg. When the sperm combines with the egg, fertilization takes place. The fertilized egg then travels up to the uterus for implantation.
At the same time, it continues to grow in size even as its cells divide and reproduce. Once this fertilized egg finds the right spot in the uterine wall to attach itself, it gets ready to implant at that spot. With implantation, the fertilized egg gets attached to the uterus lining and the pregnancy starts. So, the embryo implantation time in the uterus is generally 7 to 14 days after you have had sex. How much does it cost to get your eggs frozen?
Know More. If you want to confirm the results of your urine test — or if you want a faster result — talk to your doctor about getting a blood test. The hormone hCG can be detected in the blood as soon as a week after conception. In many cases, this cramping is mild, and it may not be accompanied by bleeding or spotting.
There are many signs and symptoms of early pregnancy, so if you suspect you may be pregnant, consider taking a home pregnancy test or calling your doctor to schedule lab testing.
There are many other reasons why you might experience cramping between periods. This includes Mittelschmerz, a German word that describes the cramp that can be felt by some women as the egg is released from the ovary.
Cramping from gas or digestive ailments can be sharp and occur in the lower abdomen. This should resolve itself. If your pregnancy test result is positive, schedule an appointment with your doctor. They can walk you through your options and discuss any concerns you may have. Implantation bleeding or spotting usually goes away on its own. Still, you may want to mention any bleeding or other vaginal discharge to your doctor, especially if the bleeding is heavy or accompanied by cramping.
In some cases, bleeding, painful cramping, or passing fluid or tissue from your vagina may be a sign of miscarriage or ectopic pregnancy. A chemical pregnancy is an early pregnancy loss that occurs shortly after implantation.
Chemical pregnancies may account for 50 to 75 percent of all…. When it comes to emergency contraception, there can be a lot of confusion. Motile sperm can survive in the female reproductive tract for up to five days. Egg transport begins at ovulation and ends once the egg reaches the uterus. Following ovulation, the fimbriated, or finger-like, end of the fallopian tube sweeps over the ovary.
Adhesive sites on the cilia, which are located on the surface of the fimbriae, are responsible for egg pickup and movement into the tube. The cilia within the tube, and muscular contractions resulting from the movement of the egg, create a forward motion. Transport through the tube takes about 30 hours.
Conditions such as pelvic infections and endometriosis can permanently impair the function of the fallopian tubes, due to scarring or damage to the fimbriae. Following ovulation, the egg is capable of fertilization for only 12 to 24 hours. Contact between the egg and sperm is random. Once the egg arrives at a specific portion of the tube, called the ampullar-isthmic junction, it rests for another 30 hours. Fertilization — sperm union with the egg — occurs in this portion of the tube.
The fertilized egg then begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive the egg.
Defects in the fallopian tube may impair transport and increase the risk of a tubal pregnancy, also called ectopic pregnancy. A membrane surrounding the egg, called the zona pellucida, has two major functions in fertilization. First, the zona pellucida contains sperm receptors that are specific for human sperm. Second, once penetrated by the sperm, the membrane becomes impermeable to penetration by other sperm. Following penetration, a series of events set the stage for the first cell division.
The single-cell embryo is called a zygote. Over the course of the next seven days, the human embryo undergoes multiple cell divisions in a process called mitosis.
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