Pre-Implantation Genetic Diagnosis. Patient Education. To become pregnant , the following steps must occur: Sperm transport — The sperm must be deposited and transported to the site of fertilization.
Egg transport — Ovulation must occur and the egg must be "picked up" by the tube. Fertilization and embryo development — Union between the sperm and egg must result. Implantation — The embryo must implant and begin to grow in the uterus. These steps are described below. Sperm Transport The transport of sperm depends on several factors: The sperm must be capable of propelling themselves through the environment of the female vagina and cervix. This environment, which is under cyclic hormonal control, must be favorable to admit the sperm without destroying them.
The sperm must possess the capability of converting to a form that can penetrate the cell membrane of the egg capacitation. Egg Transport Egg transport begins at ovulation and ends once the egg reaches the uterus. Fertilization and Embryo Development Following ovulation, the egg is capable of fertilization for only 12 to 24 hours. Implantation Once the embryo reaches the blastocyst stage, approximately five to six days after fertilization, it hatches out of its zona pellucida and begins the process of implantation in the uterus.
Recommended reading. Eating Right Before and During Pregnancy It is important to get the nutrients you need both before getting pregnant and during your pregnancy. Infertility Risk Factors Maternal age is probably the most significant factor related to a woman's ability to conceive.
Ovulation Induction Ovulation induction uses hormonal therapy to stimulate egg development and release, or ovulation, the goal being to produce a single, healthy egg. Reducing Your Risk of Infertility Your overall health is a reflection of your reproductive health.
Reproductive Surgery in Women Some women have difficulty conceiving because of problems in their reproductive system such as a congenital malformation and require surgery. The Menstrual Cycle Hormones secreted by the hypothalamus, the pituitary and the ovary are the messengers that regulate the menstrual cycle.
There, the sperm will penetrate and fertilize an egg. Once fertilized, the egg travels down the fallopian tube toward the womb, or uterus, where it will implant in the uterine wall. Beginning in the ninth week of pregnancy, and until the pregnancy ends, doctors call the developing baby a fetus. The egg comes either from a donor or a woman who wishes to become pregnant. In a laboratory, a specialist doctor works to fertilize the egg with donated sperm.
The goal is for at least one fertilized egg to implant and develop. When the egg and sperm unite, they form a zygote. The zygote contains 46 chromosomes: 23 from the female and 23 from the male. The chromosomes determine the genetic make-up of the fetus, including its sex and inherited physical characteristics, such as:.
They may also help shape factors such as personality, intelligence, and the risk of some health conditions. 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. In a blood test, hCG will show up as soon as six to eight days after you ovulate, indicating that you are pregnant. One caution: Don't decide whether you're pregnant based on how you feel. The signs of early pregnancy resemble premenstrual symptoms, and include breast swelling and tenderness, bloating, nausea, and fatigue. During these early weeks, the embryo continues to grow as cells multiply and take on specific functions in a process known as differentiation.
These specialized cells will eventually form your baby's organs and body parts. This stage of development is crucial, so if you know you are pregnant or even suspect that you could be , it's important to avoid alcohol, street drugs, and tobacco. Avoid these substances throughout your entire pregnancy, but the first 12 weeks --during which the basic formation of organs and body parts is nearly complete -- are especially crucial.
Also, don't take any prescription or over-the-counter drugs without checking with your doctor to ensure they're safe to use during pregnancy. By four weeks, the embryo is made up of three distinct layers. The inner layer will gradually develop into the lungs, liver and digestive system; a middle layer will be the baby's bones, muscles, kidneys, heart, and sex organs; and an outer layer will eventually form the skin, hair, eyes, and nervous system. By the end of the second week after fertilization, you may also begin to experience the first signs of morning sickness.
About 70 percent of all pregnant women have some traces of morning sickness, but the severity of the condition can vary from mild nausea to daily bouts of violent vomiting. For some women, symptoms are not confined to the morning, either: many complain of a rocky stomach at the end of the day. Experts believe that morning sickness is caused by the increase in hormones coursing through the system of a pregnant woman. You may also feel more fatigue than usual: Many women feel extremely tired during their first trimester of pregnancy.
Experts attribute this fatigue to the additional work your body has to do, now that it is making a baby. Trying to get pregnant can be both an exciting and nerve-wracking time. Some women do notice signs and symptoms that implantation has occurred.
Signs may include light bleeding, cramping, nausea, bloating, sore breasts, headaches, mood swings, and possibly a change in basal body temperature. Additionally, most women experience no signs of implantation at all and are in fact pregnant. Keep in mind that even if you have implantation symptoms, it takes a few days for enough hCG to build up to turn a test positive.
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