Be prepared: bodies, sperm, and eggs do a lot of work to achieve a pregnancy. Also, FYI, a lot of this information is based on animal research, especially events that happen deep in the reproductive tract. Before diving into conception, you should brush up on your knowledge of eggs and sperm , and of how ovulation works.
Ovulation is when an egg is released from the ovary, and is critical to the whole process. The cervix is what connects the vagina to the uterine cavity.
It has glands that produce cervical fluid also called cervical mucus , which passes through the vagina. You sometimes might see cervical fluid on your underwear or on toilet paper as you wipe. Cervical fluid characteristics change throughout the menstrual cycle :.
During and just after your period: You may not notice any cervical fluid. Between your period and ovulation: As estrogen levels rise, the amount of cervical fluid increases and becomes wetter, thicker and cloudier 2,3.
So why does this matter? In short, sperm swim best through wet and stretchy cervical mucus 3,4. If this fluid is absent or is thick and sticky, sperm have a hard time passing the cervix 3,4. The time period between when cervical fluid is ideal for sperm and ovulation is known as the fertile window.
Finally, sperm have an effect on the vagina. Normally the vagina is somewhat acidic, in order to protect against infection 5. When exposed to sperm, the vagina becomes less acidic 1,5. During your period , the uterus sheds the endometrium, which built up during the previous menstrual cycle.
After shedding, the endometrium waits for estrogen produced in the ovaries to rise. Estrogen causes the lining of the uterus to thicken by stimulating the endometrial cells to divide 2. This is different from men, who continuously make more sperm. About once a month, an egg is released from one of a woman's two ovaries.
This is called ovulation. The egg then enters the nearby fallopian tube that leads to the uterus. If a woman and a man have unprotected sexual intercourse, sperm that is ejaculated from the man's penis may reach the egg in the fallopian tube.
If one of the sperm cells penetrates the egg, the egg is fertilized and begins developing. The egg takes several days to travel down the fallopian tube into the uterus.
After it is in the uterus, a fertilized egg usually attaches to implants in the lining of the uterus endometrium. But not all fertilized eggs successfully implant.
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? This is because fertility treatments often involve transferring more than one embryo to the uterus at a time to increase the chances of pregnancy.
Fertility drugs can also result in more than one egg being released during ovulation. 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.
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