Thus, it becomes possible for them to pass to the ovulated egg. It is interesting that during ovulation, women experience a hormonal surge, which is accompanied by an increase in libido, as well as frequent mood swings. This can take from three minutes to five days. Surprisingly, but in most cases, only one of them takes part in fertilization.
From a biological point of view, the following stages of fertilization are distinguished:. Due to the peristaltic movements of the ciliated epithelium, the zygote moves along the fallopian tubes into the uterine cavity.
The fertilized egg is actively dividing. Upon reaching the uterus, the fertilized egg splits into two unequal parts. The smaller one will form the placenta, which will act as an organ of blood circulation, nutrition, respiration and excretion of the embryo.
The embryo will spend here all the time of intrauterine development. There are no useless processes in nature. Every detail is thought out to the smallest detail. We discover the whole world: mysterious, complex and delightful, when we are interested in the issues of conception and human development! Ovulation is the best time to conceive a baby The process of conception occurs as a result of the fusion of the female and male germ cells. What happens to the egg during ovulation? From a biological point of view, the following stages of fertilization are distinguished: denudation.
At this time, the egg is covered with a layer of specific cells that form a protective barrier for the nucleus. To get to the outer layer of the egg, sperm secrete a special enzyme called hyaluronidase. Under its influence, the protective layer of the egg liquefies, passing the most active male gametes into the middle; during the second stage, sperm penetrate through the egg membrane.
During this period, the formation of the female pronucleus, is completed, containing the maternal genetic material; the third stage is characterized by the penetration of one spermatozoid less often two or three into the cytoplasm of the egg.
Interestingly, only the head of the sperm gets in, and the tail disappears as unnecessary. Because both cells come from the exact same egg cell and sperm cell, identical twins will have the same DNA, the same sex, and a nearly identical appearance. At the point of ovulation, the uterus wall is thick. The American College of Obstetrics and Gynecology ACOG considers someone pregnant only once the embryo is successfully implanted against the uterine wall. In other words, implantation marks the beginning of a pregnancy.
The embryo, however, might not implant. Emergency contraception , intrauterine devices IUDs , and infertility could prevent the embryo from implanting. In the event that ovulation has already occurred when you take Plan B, the U. Food and Drug Administration notes that it may prevent a fertilized egg from implanting. An IUD works by thickening cervical mucus. This can both prevent ovulation and create an environment that kills or immobilizes sperm, preventing the possibility of fertilization.
Rather, they prevent pregnancy from happening. IUDs and emergency contraceptive pills are both extremely effective forms of contraception. According to the World Health Organization , both are 99 percent effective at avoiding pregnancy.
About 90 percent of ectopic pregnancies occur when the embryo implants in one of the fallopian tubes. It could also attach to the cervix or abdominal cavity. Ectopic pregnancies are medical emergencies that need prompt treatment to prevent a tube rupture.
After implantation occurs, the placenta forms. At this point, your body will produce the hormone human chorionic gonadotropin hCG. According to Mayo Clinic , hCG levels should double every two to three days in the early stages of pregnancy. Pregnancy tests work by detecting hCG in your body. You can either test your urine, as with home pregnancy tests, or test your blood via your healthcare provider.
This will make it easier for the test to measure your hCG levels. Most babies are born in week 39 or Week 1 is actually retroactively counted from the first day of your last period. 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. However, soon after fertilization in some cases, and increasingly as time goes on, you may experience:. A pregnancy test is likely to produce an accurate result if a person takes it 1 week after the first day of the next expected period. Learn more. Fetal macrosomia is a condition wherein a baby is born at a heavier birth weight than usual.
Learn more about fetal macrosomia here. A study links air pollution to almost 6 million premature births each year. Indoor air pollution is responsible for two-thirds of these perinatal….
Amniotic fluid embolism is a dangerous pregnancy complication that develops due to a severe allergic reaction. Learn more about it, including symptoms,. Pregnancy dreams can be more realistic, detailed, or frightening than usual. However, they are not usually a cause for concern. Learn more here. Your pregnancy at week 3.
Medically reviewed by Debra Sullivan, Ph. Fertilization How does it happen? What are chromosomes?
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