What is Prenatal Development? Prenatal Development- is the process by which a baby-to-be grows inside the mother. The process normally takes about nine months for a full term pregnancy, one that goes to completion. A full term pregnancy lasts 280 days which is 40 weeks, this is counting the first day of your last menstrual period. Doctors will refer to a full term pregnancy anywhere between 38-42 weeks. Why do you think it varies by two weeks?
Timeline of Pregancy The timeline of pregnancy can be divided into three trimesters, or a three month time periods.
First Trimester It begins at the moment of conception. The Zygote- the first 8 weeks after the conception. The zygote contains all of the genetic information (DNA) necessary to become a child. Half of the genetic information comes from the mother' s egg and half from the father' s sperm. The zygote spends the next few days traveling down the Fallopian tube and divides to form a ball of cells.
First Trimester The zygote continues to divide, creating an inner group of cells with an outer shell. This stage is called a blastocyst. The inner group of cells will become the embryo, while the outer group of cells will become the membranes that nourish and protect it. The blastocyst reaches the womb (uterus) around day 5, and implants into the uterine wall on about day 6. At this point in the mother's menstrual cycle, the lining of the uterus has grown and is ready to support a fetus. The blastocyst sticks tightly to the lining, where it receives nourishment via the mother's bloodstream.
First Trimester • The Embryo- developing baby is called this after 8 weeks. • During this time cells continue to develop rapidly. In a few weeks the embryo is the size of the head of a pin. • There is rapid growth, and the baby's main external features begin to take form. It is during this critical period (most of the first trimester) that the growing baby is most susceptible to damage. The following can interfere with the baby's development: • Alcohol, certain prescription and recreational drugs, and other substances that cause birth defects • Infection (such as rubella) • Nutritional deficiencies • X-rays or radiation therapy
Three Layers That Form Humans Ectoderm-outer layer of cells becomes the skin, hair and nails. It also forms the nervous system. Mesoderm- or middle layer, eventually grows the bones, muscles, blood vessels, and some eternal organs such as the heart, kidneys, and reproductive organs. Endoderm- internal cell layer eventually becomes the stomach, liver and lungs.
First 9 Weeks http://www.babycenter.com/2_inside-pregnancy-weeks-1-to-9_10302602.bc
Changes in You- Could You Be Pregnant? 10. Tender, swollen breasts-One of the early signs of pregnancy is sensitive, sore breasts caused by increasing levels of hormones. 9. Fatigue-No one knows for sure what causes early pregnancy fatigue, but it's possible that rapidly increasing levels of the hormone progesterone are contributing to your sleepiness. You should start to feel more energetic once you hit your second trimester. 8. Implantation bleeding-Some women have a small amount of vaginal bleeding around 11 or 12 days after conception (close to the time you might notice a missed period). The bleeding may be caused by the fertilized egg burrowing into the blood-rich lining of your uterus— but no one knows for sure. The bleeding is very light (appearing as red spotting or pink or reddish-brown staining) and lasts only a day or two. (Let your practitioner know if you notice any bleeding or spotting, particularly if it's accompanied by pain, since this can be a sign of an ectopic pregnancy.) 7. Nausea or vomiting-If you're like most women, morning sickness won't hit until about a month after conception. (A lucky few escape it altogether.) But some women do start to feel queasy a bit earlier. And not just in the morning, either — pregnancy-related nausea and vomiting can be a problem morning, noon, or night.
Symptoms 6. Increased sensitivity to odors If you're newly pregnant, it's not uncommon to feel repelled by the smell of a bologna sandwich or cup of coffee and for certain aromas to trigger your gag reflex. Though no one knows for sure, this may be a side effect of rapidly increasing amounts of estrogen in your system. You may also find that certain foods you used to enjoy are suddenly completely repulsive to you. 5. Abdominal bloating Hormonal changes in early pregnancy may leave you feeling bloated, similar to the feeling some women have just before their period arrives. 4. Frequent urination Shortly after you become pregnant, you may find yourself hurrying to the bathroom all the time. Why? Mostly because during pregnancy the amount of blood and other fluids in your body increases, which leads to extra fluid being processed by your kidneys and ending up in your bladder. 3. A missed period If you're usually pretty regular and your period doesn't arrive on time, you'll probably take a pregnancy test long before you notice any of the above symptoms 2. Your basal body temperature stays high If you've been charting your basal body temperature and you see that your temperature has stayed elevated for 18 days in a row, you're probably pregnant. 1. The proof: A positive home pregnancy test In spite of what you might read on the box, many home pregnancy tests are not sensitive enough to detect most pregnancies until about a week after a missed period. So if you decide to take one earlier than that and get a negative result, try again in a few days.
10-14 Weeks http://www.babycenter.com/2_inside-pregnancy-weeks-1-to-9_10302602.bc
Key Terms During Pregnancy Placenta- the spongy, vascular organ that supplies the baby with maternal blood and nutrients through the umbilical cord. Umbilical Cord- The umbilical vein supplies the fetus with oxygenated, nutrient-rich blood from the placenta. Afterwards the umbilical arteries return the deoxygenated, nutrient-depleted blood. Amniotic Fluid- the liquid surrounding and protecting the baby within the amniotic sac throughout pregnancy. Amniotic Sac- the membrane within the uterus that contains the baby and the amniotic fluid.
Diagnostic Testing Chorionic Villus Sampling (CVS): This diagnostic test involves collecting cells from the placenta, which are then sent to a lab for genetic analysis. CVS can identify whether your baby has any of hundreds of chromosomal abnormalities and other genetic disorders. It's done in the first trimester, usually between 11 and 12 weeks, making it an earlier alternative to another diagnostic genetic test called amniocentesis, which is done between 16 and 20 weeks. This test is 99% accurate.
Diagnostic Testing Amniocentesis- is a prenatal test that allows your healthcare practitioner to gather information about your baby's health and development from a sample of your amniotic fluid. This is the fluid that surrounds your baby in the uterus. Amniocentesis is usually done when a woman is between 16 and 20 weeks pregnant. Women who choose to have this test are primarily those at increased risk for genetic and chromosomal problems, in part because the test is invasive and carries a small risk of miscarriage.
Ultrasound Imaging Ultrasound Imaging- is a process that uses sound waves to create video and still images of the fetus inside the uterus. The ultrasound image is called a sonogram. http://www.babycenter.com/2_ultrasound-exam_3658842.bc
Miscarriage Miscarriage is the loss of a pregnancy in the first 20 weeks. About 15 to 20 percent of known pregnancies end in miscarriage, and more than 80 percent of these losses happen before 12 weeks. This doesn't include situations in which you lose a fertilized egg before you get a positive pregnancy test. Studies have found that 30 to 50 percent of fertilized eggs are lost before a woman finds out she's pregnant, because they're lost so early that she goes on to get her period about on time -- in other words the woman doesn't realize she was pregnant at all. If you lose a baby after 20 weeks of pregnancy, it's called a stillbirth.
What causes a miscarriage? Between 50 and 70 percent of first trimester miscarriages are thought to be random events caused by chromosomal abnormalities in the fertilized egg. Most often, this means that the egg or sperm had the wrong number of chromosomes, and as a result, the fertilized egg can't develop normally. In other cases, a miscarriage is caused by problems that occur during the delicate process of early development — for example, when an egg doesn't implant properly in the uterus or an embryo has structural defects that don't allow it to continue developing. Since most healthcare practitioners won't do a full-scale workup after a single miscarriage, it's usually impossible to tell why the pregnancy was lost. And even when a detailed evaluation is performed — say after you've had two or three consecutive miscarriages — the cause still remains unknown in about half of cases.
Miscarriage Once your baby has a heartbeat — usually visible on ultrasound at around 6 weeks — your odds of having a miscarriage drop significantly. Coping with miscarriage- Understand that it's not your fault.• Give yourself time to heal.• Take time off from work.• Don't expect your partner to grieve in the same way.• Don't close yourself off from others.• Get support
What kinds of things might put me at a higher risk for miscarriage? • Age: Older women are more likely to conceive babies with chromosomal abnormalities, and to miscarry them as a result. In fact, 40-year-olds are about twice as likely to miscarry as 20-year-olds. • A history of miscarriages: Women who have had two or more miscarriages in a row are more likely than other women to miscarry again. • Certain chronic diseases or disorders: Poorly controlled diabetes, certain inherited blood clotting disorders, certain autoimmune disorders (such as antiphosphilipid syndrome or lupus), and certain hormonal disorders (such as polycystic ovary syndrome). • Uterine or cervical problems: Having certain uterine abnormalities or a weak or abnormally short cervix (known as cervical insufficiency). • A history of birth defects or genetic problems: Having had a child with a birth defect, or a family history (or a partner with a family history) of genetic problems. Your risk of miscarriage also rises with each child you bear and if you get pregnant within three months after giving birth
• Smoking, drinking, and using drugs: Smoking a lot, drinking too much alcohol, and using drugs like cocaine and ecstasy during pregnancy can all increase your risk for miscarriage. And some studies show an association between drinking four or more cups of coffee a day and a higher risk of miscarriage. Infections • Taking certain medications: Some medications have been linked to increased risk of miscarriage, so it's important to ask your caregiver about the safety of any medications you're taking even while you're trying to conceive. This goes for prescription and over-the-counter drugs, including nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and aspirin. • Exposure to environmental toxins: Environmental factors that might increase your risk include lead; arsenic; some chemicals, like formaldehyde, benzene, and ethylene oxide; and large doses of radiation or anesthetic gases. • Paternal factors: Little is known about how the father's condition may contribute to a couple's risk for miscarriage, though the risk increases with the father's age. Researchers are studying the extent to which sperm could be damaged by environmental toxins but still manage to fertilize an egg. Some studies have found a greater risk of miscarriage when the father has been exposed to mercury, lead, and some industrial chemicals and pesticides.
Second Trimester 13-24 Weeks http://www.babycenter.com/2_inside-pregnancy-weeks-15-to-20_10308111.bc
What’s happening in the second trimester? Lanugo-Downy hair on the body of the fetus and newborn baby. It is the first hair to be produced by the fetal hair follicles, usually appearing on the fetus at about five months of gestation. It is very fine, soft, and usually un-pigmented. Although lanugo is normally shed before birth around seven or eight months of gestation, it is sometimes present at birth. This is not a cause for concern: lanugo will disappear within a few days or weeks
What’s happening in the second trimester? His or her sex organs are now fully formed. Their eyes are fused shut but they can sense light and will often move and squint if a bright light is shine on the uterus.
What does an ultrasound around 16-20 weeks determine? Check your baby's heartbeatTo make sure it's normal, she'll measure the number of beats per minute. Confirm your baby's locationThis is to make sure your baby's growing inside your uterus and your pregnancy isn't ectopic, meaning the embryo is lodged in a fallopian tube or elsewhere other than the uterus. But in most cases, you would have had symptoms of an ectopic pregnancy early on and a scan done at that point to confirm the problem. Measure your baby's sizeThe sonographer will measure your baby across the skull, along the thighbone, and around the abdomen in an attempt to make sure he's about the size he should be for his age. If this is your first ultrasound and your baby is more than two weeks behind or ahead of where he should be, size-wise, it's likely that your due date is off and you'll be given a new one. If your practitioner has any concerns about how your baby is growing, she'll order one or more follow-up ultrasounds to check his progress.
What does an ultrasound around 16-20 weeks determine? Check to see if there's more than one babyBy now you'll probably already know if you're carrying twins or higher multiples. Most women pregnant with multiples measure large in their first trimester and have an ultrasound at that point to confirm the number of babies. Check the location of the placentaIf the placenta is covering the cervix (placenta previa), it can cause painless but severe bleeding later in the pregnancy. If your practitioner detects this condition, she'll most likely order a follow-up scan early in your third trimester to see if the placenta is still covering the cervix. In the meantime, don't panic! Only a small percentage of placenta previas detected on an ultrasound before 20 weeks are still there at delivery. Assess the amount of amniotic fluid in the uterusIf the sonogram shows that you have too much or too little amniotic fluid, there may be a problem. You'll have a complete work-up to see if the cause can be identified, and your practitioner may want to monitor you with regular ultrasounds.
What does an ultrasound around 16-20 weeks determine? Check the baby for physical abnormalitiesYour practitioner will look closely at your baby's basic anatomy, including his head, neck, chest, heart, spine, stomach, kidneys, bladder, arms, legs, and umbilical cord to make sure they're developing properly. If you've had any suspicious results from a multiple marker or first trimester screening, or if there's any other cause for concern, the technician will do a more thorough (level II) scan to check for signs of a birth defect or Down syndrome. Try to determine your baby's sexIf you'd like to find out whether your baby's a boy or a girl, you usually can at the mid-pregnancy ultrasound (16 to 20 weeks), unless, for example, your child's hand is covering his genitals during the scan. In some cases, it's important for your practitioner to know your baby's sex — for example, if the baby is thought to be at risk for certain congenital conditions.