Pregnancy (redirected from pregnancy edema)

Pregnancy 

Definition

The period from conception to birth. After the egg is fertilized by a sperm and then implanted in the lining of the uterus, it develops into the placenta and embryo, and later into a fetus. Pregnancy usually lasts 40 weeks, beginning from the first day of the woman's last menstrual period, and is divided into three trimesters, each lasting three months.

Description

Pregnancy is a state in which a woman carries a fertilized egg inside her body. Due to technological advances, pregnancy is increasingly occurring among older women in the United States.

First month

At the end of the first month, the embryo is about a third of an inch long, and its head and trunk-plus the beginnings of arms and legs-have started to develop. The embryo receives nutrients and eliminates waste through the umbilical cord and placenta. By the end of the first month, the liver and digestive system begin to develop, and the heart starts to beat.

Second month

In this month, the heart starts to pump and the nervous system (including the brain and spinal cord) begins to develop. The 1 in (2.5 cm) long fetus has a complete cartilage skeleton, which is replaced by bone cells by month's end. Arms, legs and all of the major organs begin to appear. Facial features begin to form.

Third month

By now, the fetus has grown to 4 in (10 cm) and weighs a little more than an ounce (28 g). Now the major blood vessels and the roof of the mouth are almost completed, as the face starts to take on a more recognizably human appearance. Fingers and toes appear. All the major organs are now beginning to form; the kidneys are now functional and the four chambers of the heart are complete.

Fourth month

The fetus begins to kick and swallow, although most women still can't feel the baby move at this point. Now 4 oz (112 g), the fetus can hear and urinate, and has established sleep-wake cycles. All organs are now fully formed, although they will continue to grow for the next five months. The fetus has skin, eyebrows, and hair.

Fifth month

Now weighing up to a 1 lb (454 g) and measuring 8-12 in (20-30 cm), the fetus experiences rapid growth as its internal organs continue to grow. At this point, the mother may feel her baby move, and she can hear the heartbeat with a stethoscope.

Sixth month

Even though its lungs are not fully developed, a fetus born during this month can survive with intensive care. Weighing 1-1.5 lbs (454-681 g), the fetus is red, wrinkly, and covered with fine hair all over its body. The fetus will grow very fast during this month as its organs continue to develop.

Seventh month

There is a better chance that a fetus born during this month will survive. The fetus continues to grow rapidly, and may weigh as much as 3 lb (1.3 kg) by now. Now the fetus can suck its thumb and look around its watery womb with open eyes.

Eighth month

Growth continues but slows down as the baby begins to take up most of the room inside the uterus. Now weighing 4-5 lbs (1.8-2.3 kg) and measuring 16-18 in (40-45 cm) long, the fetus may at this time prepare for delivery next month by moving into the head-down position.

Ninth month

Adding 0.5 lb (227 g) a week as the due date approaches, the fetus drops lower into the mother's abdomen and prepares for the onset of labor, which may begin any time between the 37th and 42nd week of gestation. Most healthy babies will weigh 6-9 lb (2.7-4 kg) at birth, and will be about 20 in. long.

Causes and symptoms

The first sign of pregnancy is usually a missed menstrual period, although some women bleed in the beginning. A woman's breasts swell and may become tender as the mammary glands prepare for eventual breastfeeding. Nipples begin to enlarge and the veins over the surface of the breasts become more noticeable.

Nausea and vomiting are very common symptoms and are usually worse in the morning and during the first trimester of pregnancy. They are usually caused by hormonal changes, in particular, increased levels of progesterone. Women may feel worse when their stomach is empty, so it is a good idea to eat several small meals throughout the day, and to keep things like crackers on hand to eat even before getting out of bed in the morning.

Many women also feel extremely tired during the early weeks. Frequent urination is common, and there

Pregnancy usually lasts 40 weeks in humans, beginning from the first day of the woman's last menstrual period, and is divided into three trimesters. The illustration above depicts the position of the developing fetus during each trimester.

(Illustration by Electronic Illustrators Group.)

may be a creamy white discharge from the vagina. Some women crave certain foods, and an extreme sensitivity to smell may worsen the nausea. Weight begins to increase.

In the second trimester (13-28 weeks) a woman begins to look noticeably pregnant and the enlarged uterus is easy to feel. The nipples get bigger and darker, skin may darken, and some women may feel flushed and warm. Appetite may increase. By the 22nd week, most women have felt the baby move. During the second trimester, nausea and vomiting often fade away, and the pregnant woman often feels much better and more energetic. Heart rate increases as does the volume of blood in the body.

By the third trimester (29-40 weeks), many women begin to experience a range of common symptoms. Stretch marks may develop on abdomen, breasts, and thighs, and a dark line may appear from the navel to pubic hair. A thin fluid may be expressed from the nipples. Many women feel hot, sweat easily and often find it hard to get comfortable. Kicks from an active baby may cause sharp pains, and lower backaches are common. More rest is needed as the woman copes with the added stress of extra weight. Braxton Hicks contractions may get stronger.

At about the 36th week in a first pregnancy (later in repeat pregnancies), the baby's head drops down low into the pelvis. This may relieve pressure on the upper abdomen and the lungs, allowing a woman to breathe more easily. However, the new position places more pressure on the bladder.

A healthy gain for most women is between 25 and 35 pounds. Women who are overweight should gain less; and women who are underweight should gain more. On average, pregnant women need an additional 300 calories a day. Generally, women will gain three to five pounds in the first three months, adding one to two pounds a week until the baby is born. An average, healthy full-term baby at birth weighs 7.5 lb (3.4 kg), and the placenta and fluid together weigh another 3.5 lb. The remaining weight that a woman gains during pregnancy is mostly due to water retention and fat stores. Her breasts, for instance, gain about 2 lb. in weight, and she gains another 4 lb due to the increased blood volume of pregnancy.

In addition to the typical, common symptoms of pregnancy, some women experience other problems that may be annoying, but which usually disappear after delivery. Constipation may develop as a result of food passing more slowly through the intestine. Hemorrhoids and heartburn are fairly common during late pregnancy. Gums may become more sensitive and bleed more easily; eyes may dry out, making contact lenses feel painful. Pica (a craving to eat substances other than food) may occur. Swollen ankles and varicose veins may be a problem in the second half of pregnancy, and chloasma may appear on the face.

Chloasma, also known as the "mask of pregnancy" or melasma, is caused by hormonal changes that result in blotches of pale brown skin appearing on the forehead, cheeks, and nose. These blotches may merge into one dark mask. It usually fades gradually after pregnancy, but it may become permanent or recur with subsequent pregnancies. Some women also find that the line running from the top to the bottom of their abdomen darkens. This is called the linea nigra.

While the above symptoms are all considered to be normal, there are some symptoms that could be a sign of a more dangerous underlying problem. A pregnant woman with any of the following signs should contact her doctor immediately:

Diagnosis

Many women first discover they are pregnant after a positive home pregnancy test. Pregnancy urine tests check for the presence of human chorionic gonadotropin (hCG), which is produced by a placenta. The newest home tests can detect pregnancy on the day of the missed menstrual period.

Home pregnancy tests are more than 97% accurate if the result is positive, and about 80% accurate if the result is negative. If the result is negative and there is no menstrual period within another week, the pregnancy test should be repeated. While home pregnancy tests are very accurate, they are less accurate than a pregnancy test conducted at a lab. For this reason, women may want to consider having a second pregnancy test conducted at their doctor's office to be sure of the accuracy of the result.

Blood tests to determine pregnancy are usually used only when a very early diagnosis of pregnancy is needed. This more expensive test, which also looks for hCG, can produce a result within nine to 12 days after conception.

Once pregnancy has been confirmed, there are a range of screening tests that can be done to screen for birth defects, which affect about 3% of unborn children. Two tests are recommended for all pregnant women: alpha-fetoprotein (AFP) and the triple marker test.

Other tests are recommended for women at higher risk for having a child with a birth defect. This would include women over age 35, who had another child or a close relative with a birth defect, or who have been exposed to certain drugs or high levels of radiation. Women with any of these risk factors may want to consider amniocentesis, chorionic villus sampling (CVS) or ultrasound.

Other prenatal tests

There are a range of other prenatal tests that are routinely performed, including:

Treatment

Prenatal care is vitally important for the health of the unborn baby. A pregnant woman should be sure to eat a balanced, nutritious diet of frequent, small meals. Women should begin taking 400 mcg of folic acid several months before becoming pregnant, as folic acid has been shown to reduce the risk of spinal cord defects, such as spina bifida.

No medication (not even a nonprescription drug) should be taken except under medical supervision, since it could pass from the mother through the placenta to the developing baby. Some drugs, called teratogens, have been proven harmful to a fetus, but no drug should be considered completely safe (especially during early pregnancy). Drugs taken during the first three months of a pregnancy may interfere with the normal formation of the baby's organs, leading to birth defects. Drugs taken later on in pregnancy may slow the baby's growth rate, or they may damage specific fetal tissue (such as the developing teeth), or cause preterm birth.

To have the best chance of having a healthy baby, a pregnant woman should avoid:

Nutrition

Women should begin following a healthy diet even before they become pregnant. This means cutting back on high-calorie, high-fat, high-sugar snacks, and increasing the amount of fruits, vegetables and whole grains in her diet. Once she becomes pregnant, she should make sure to get at least six to 11 servings of breads and other whole grains, three to five servings of vegetables, two to four servings of fruits, four to six servings of milk and milk products, three to four servings of meat and protein foods, and six to eight glasses of water. She should limit caffeine to no more than one soft drink or cup of coffee per day.

Prognosis

Pregnancy is a natural condition that usually causes little discomfort provided the woman takes care of herself and gets adequate prenatal care. Childbirth education classes for the woman and her partner help prepare the couple for labor and delivery.

Key terms

Alpha-fetoprotein — A substance produced by a fetus' liver that can be found in the amniotic fluid and in the mother's blood. Abnormally high levels of this substance suggests there may be defects in the fetal neural tube, a structure that will include the brain and spinal cord when completely developed. Abnormally low levels suggest the possibility of Down' syndrome.

Braxton Hicks' contractions — Short, fairly painless uterine contractions during pregnancy that may be mistaken for labor pains. They allow the uterus to grow and help circulate blood through the uterine blood vessels.

Chloasma — A skin discoloration common during pregnancy, also known as the "mask of pregnancy" or melasma, in which blotches of pale brown skin appear on the face. It is usually caused by hormonal changes. The blotches may appear in the forehead, cheeks, and nose, and may merge into one dark mask. It usually fades gradually after pregnancy, but it may become permanent or recur with subsequent pregnancies. Some women may also find that the line running from the top to the bottom of their abdomen darkens. This is called the linea nigra.

Embryo — An unborn child during the first eight weeks of development following conception (fertilization with sperm). For the rest of pregnancy, the embryo is known as a fetus.

Fetus — An unborn child from the end of the eights week after fertilization until birth.

Human chorionic gonadotropin (hCG) — A hormone produced by the placenta during pregnancy.

Placenta — The organ that develops in the uterus during pregnancy that links the blood supplies of the mother and baby.

Rhythm method — The oldest method of contraception with a very high failure rate, in which partners periodically refrain from having sex during ovulation. Ovulation is predicted on the basis of a woman's previous menstrual cycle.

Spina bifida — A congenital defect in which part of the vertebrae fail to develop completely, leaving a portion of the spinal cord exposed.

Prevention

There are many ways to avoid pregnancy. A woman has a choice of many methods of contraception which will prevent pregnancy, including (in order of least to most effective):

Resources

Organizations

Healthy Mothers, Healthy Babies National Coalition. 409 12th St., Washington, DC 20024. (202) 638-5577.

National Institute of Child Health and Human Development. 9000 Rockville Pike, Bldg. 31, Rm. 2A32, Bethesda, MD 20892. (301) 496-5133.

Positive Pregnancy and Parenting Fitness. 51 Saltrock Rd., Baltic, CT 06330. (203) 822-8573.

Other

Doulas of North America http://www.dona.com.

Planned Parenthood. http://www.plannedparenthood.org.

Pregnancy Information. http://www.childbirth.org.

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pregnancy /preg·nan·cy/ (preg´nan-se)

1. the condition of having a developing embryo or fetus in the body, after union of an oocyte and spermatozoon.preg´nant

Pregnancy—Uterine levels.

2. the period during which one is pregnant; see gestation period, under period.

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abdominal pregnancy  ectopic pregnancy within the abdominal cavity.

ampullar pregnancy  ectopic pregnancy in the ampulla of the uterine tube.

cervical pregnancy  ectopic pregnancy within the cervical canal.

combined pregnancy  simultaneous intrauterine and extrauterine pregnancies.

cornual pregnancy  pregnancy in one of the horns of a bicornuate uterus.

ectopic pregnancy , extrauterine pregnancy development of the embryo outside the uterine cavity.

Diagram showing locations of ectopic (extrauterine) pregnancy.

false pregnancy  development of the signs of pregnancy without the presence of an embryo.

heterotopic pregnancy  combined p.

interstitial pregnancy  ectopic pregnancy in the part of the uterine tube within the uterine wall.

intraligamentary pregnancy , intraligamentous pregnancy ectopic pregnancy within the broad ligament.

molar pregnancy  conversion of the early embryo into a mole.

multiple pregnancy  presence of more than one fetus in the uterus at the same time.

mural pregnancy  interstitial p.

ovarian pregnancy  ectopic pregnancy occurring in an ovary.

phantom pregnancy  false pregnancy due to psychogenic factors.

postterm pregnancy  one that has extended beyond 42 weeks from the onset of the last menstrual period or 40 completed weeks from conception.

tubal pregnancy  ectopic pregnancy within a uterine tube.

tuboabdominal pregnancy  ectopic pregnancy partly in the fimbriated end of a uterine tube and partly in the abdominal cavity.

tubo-ovarian pregnancy  ectopic pregnancy occurring partly in the ovary and partly in a uterine tube.

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preg·nan·cy (prgnn-s)

n.

1. The condition of a woman or female mammal from conception until birth; the condition of being pregnant.

2. The period during which a woman or female mammal is pregnant. Also called cyesis.

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pregnancy,

n the gestational process that lasts approximately forty weeks in humans, during which a fertilized egg develops into a distinct individual within the mother's uterus.

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pregnancy (preg´nncē),

n the gestational process, comprising the growth and development within a woman of a new individual from conception through the embryonic and fetal periods to birth. Pregnancy lasts approximately 266 days from the day of fertilization, but is clinically considered to last 280 days (40 weeks, or 10 lunar months) from the first day of the last menstrual period.

pregnancy gingivitis,

n See gingivitis, pregnancy.

pregnancy tumor,

n See granuloma, pregnancy; granuloma, pyogenic.

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pregnancy

the condition of having a developing embryo or fetus in the body, after union of an ovum and spermatozoon. The duration of pregnancy in each animal species varies widely. See also gestation.

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abdominal pregnancy

ectopic pregnancy within the peritoneal cavity.

pregnancy diagnosis

see pregnancy tests (below).

Pregnancy diagnosis by rectal examination in a cow. By permission from Parkinson TJ, England GCW, Arthur GH, Arthur's Veterinary Reproduction and Obstetrics, Saunders, 2001

pregnancy duration

see gestation period.

ectopic pregnancy, extrauterine pregnancy

development of the fertilized ovum outside the cavity of the uterus. The site of implantation usually is one of the uterine tubes. Not recorded as occurring in animals.

pregnancy edema

see udder edema.

pregnancy failure

includes fetal resorption, fetal mummification, abortion, miscarriage.

false pregnancy, phantom pregnancy

development of all the signs of pregnancy without the presence of an embryo. Commonly seen in bitches, 40 to 60 days after estrus, associated with the persistence of corpora lutea. There may be all the signs of impending parturition with mammary development, milk and behavior changes including nest building and aggression. Tends to recur in the same bitch. Sometimes pyometra is a sequel. Called also pseudopregnancy, pseudocyesis.

pregnancy prolonged

see prolonged gestation.

pregnancy rate (overall)

the percentage of all services given to a group of females during a defined period which result in pregnancies (diagnosed at 42 days or more after service), or percentage of all females which become pregnant during a specified (usually seasonal) breeding period.

pregnancy specific protein B

a potential pregnancy diagnosis test; secreted by the trophoblastic ectoderm and present in the cow's peripheral circulation at day 24 of gestation; persists in the circulation for long periods after parturition.

pregnancy termination

in the early stages of pregnancy prostaglandins are used; in the later stages corticosteroids are used. The efficacy of the various treatments varies between the species. See also parturition induction.

pregnancy tests

cover a wide range with different tests being most satisfactory in different species. Mare—ultrasound at 24 days, rectal palpation of the uterus 30 to 35 days, serum gonadotropin levels at day 40 to 100. Cow—rectal palpation from 35 days onwards; progesterone assay in milk at day 24 after breeding. Ewes—ultrasound after 60 days, rectal probe after 70 days. Sow—estrone sulfate content of the urine at 25 days, rectal examination at 30 days, ultrasound at 28 days. Bitch, queen—palpation through the abdominal wall in a cooperative patient at 21 days, radiographic examination at day 45, ultrasound at 35 days.

pregnancy toxemia

is recorded in ruminants.

1. Ewes. Pregancy toxemia occurs only in the last month of pregnancy, most commonly in fat ewes carrying twin lambs, and in circumstances in which the feed supply is declining. See also fat ewe pregnancy toxemia.

2. Cows. Fat cows in the last 6 weeks of pregnancy and which suffer a sharp decrease in feed are subject. Dairy cows that calve in an excessively fat state and then are stressed nutritionally develop a syndrome very similar to pregnancy toxemia but called more commonly fat cow syndrome. In all of the diseases there is blindness, recumbency and severe ketosis. In early cases there may be some excitation, even convulsions.

3. in guinea pig sows, particularly obese ones, uteroplacental ischemia caused by aortic compression and iliac arterial hypoplasia occurs in late pregancy, causing lethargy, anorexia and rapid death.

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pregnancy Obstetrics The state of gestation; the period of time from confirmation of implantation of a fertilized egg within the uterus–presumptive signs of pregnancy include missed menses or a positive pregnancy test [45 CFR 46.203(b)]–until the fetus has entirely left the uterus–ie, been delivered. See At-risk pregnancy, Cervical pregnancy, Clinical pregnancy, Crisis pregnancy, Ectopic pregnancy, Fatty liver of pregnancy, High-risk pregnancy, Mole pregnancy, Multifetal pregnancy, Postterm pregnancy, Pseudopreganancy, PUPPP, Selective termination of pregnancy, Sympathy pregnancy, Teenage pregnancy, Tubal pregnancy, Unwanted pregnancy.