What Is Pregnancy? How Do I Know If I Am Pregnant?

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Main Category: Pregnancy / Obstetrics
Also Included In: Women's Health / Gynecology
Article Date: 04 Jun 2009 - 10:00 PDT

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Put simply, if any of these signs and symptoms apply to you, there is a good chance you are pregnant. The first symptom is a must, the others are possibilities. In other words, if your breasts are tender but your period has come, you are not pregnant - you must have a missed period. 1. Missed period. 2. Nausea with or without vomiting. 3. Tiredness. 4. Dizziness. 5. Breast changes. 6. Breast tenderness. 6. Frequent urination.

Nausea generally affects pregnant women during the first three to four months of the pregnancy. Tiredness tends to be more acute during the first and last three months.

How do I know if I am pregnant?

If you suspect you are pregnant, you have two options towards finding out:

• See your doctor.
• Buy a home pregnancy test.

If the home pregnancy test confirms you are pregnant you should go to a doctor or midwife for further confirmation. Not only will the doctor find out whether you are pregnant, he/she will also make sure you receive proper advice and support right from the start. In the UK midwives are usually based at GP (general practitioner, primary care physician) surgeries, a midwife unit, or a local hospital.

Pregnancy is diagnosed by detecting the presence of HCG (human chorionic gonadotropin) in the woman's blood or urine. GCG is a pregnancy hormone which is present in a woman as soon as she becomes pregnant, even before her period is due. The more HCG there is in the woman the higher are her chances of having a multiple pregnancy. However, this needs to be confirmed with an abdominal, or transvaginal scan. The scan can tell how many embryos there are, as well as checking where exactly in the womb the embryo is located.

What is pregnancy? The start of conception

A male sperm penetrates an egg and fertilizes it. This usually happens in the woman's fallopian tube after ovulation (the matured egg was released from one of her ovaries).

Sperm has 23 chromosomes, including one of two types of sex chromosomes - X chromosome or Y chromosome. A sperm with an X chromosome that fertilizes an egg will produce a girl, while a Y chromosome sperm will produce a boy. Each egg also has 23 chromosomes. 46 chromosomes are required to make a human. The fusion of sperm and egg makes 46.

As soon as it is fertilized, the zygote starts to divide; it continues doing so until there is a cluster of cells. After five to seven days of dividing and growing, it attaches itself to the wall of the uterus (womb) and puts out root-like veins called villi. The villi make sure the embryo is well anchored to the lining of the uterus. These villi will eventually become the placenta, which feeds and protects the embryo/fetus.

Through the placenta the embryo/fetus receives its oxygen and nutrition, and expels waste.

What is the difference between an embryo, a fetus and a zygote?

The embryo exists from the implantation of the zygote (fusion of sperm and ovum) to when all the organs are formed (around 12 weeks) when it becomes a fetus.

When the sperm and egg meet (fuse) a zygote is produced. The cells of the zygote start multiplying (dividing) many times. The zygote grows and develops in the fallopian tubes. The moment it is implanted in the wall of the uterus it becomes an embryo. The difference between a zygote and an embryo is the timing.

The embryo continues developing until most of the organs are formed - around the 12th week. When all the organs are there it becomes a fetus.

The word zygote comes from the Greek word zygotes, meaning "yoked". The Greek word zygon means "yoke". The word embryo comes from the Medieval Latin word embryo, which comes from the Greek word embryon, meaning "young animal, fruit of the womb, that which grows". The word fetus comes from the Latin word fetus, meaning "offspring, bringing forth, hatching of young".

The development or the embryo is rapid - specialized cells create the vital organs, including the bones, muscles, blood, and the nervous system.

When the embryo becomes a fetus it is about 1 inch (2.4cm) long. Most of its internal organs are formed. The external features, such as the ears, mouth, nose, and eyes are evident, while fingers and toes start to appear.

As the fetus gets bigger, so does the uterus. The fetus is surrounded by a fluid, called amniotic fluid. Just before a woman gives birth her "waters break", that water is the amniotic fluid.

The fetus lives in this fluid and swallows it constantly. An amniotic test can be carried out during the pregnancy to find out about the baby's health.

Most pregnancies last from 37 to about 42 weeks. Health care professionals calculate the delivery date 40 weeks from the date of conception (the date the sperm and egg fused). According to the National Health Service, UK, only about 1 in every 20 births actually takes place on the due date. A baby who is born before 37 weeks after conception is considered pre-term (premature).

A pregnancy has 3 trimesters

• The 1st trimester
  These are the first 13 weeks of the pregnancy. The baby develops the fastest during this period and becomes almost fully formed by the end of it. Women say this trimester is when they are most likely to feel tired, nausea, and breast tenderness.


• The 2nd trimester
  This is from the 14th to 26th week of the pregnancy. During this trimester it becomes obvious that the mother is pregnant. As well as weighing more because of the growing baby, the expanded uterus, the placenta, and the amniotic fluid, the mother lays down extra reserves of fat. The baby continues to grow and develop. During the second trimester the mother will feel the baby's movements, as will others if they place their hands on the mothers stomach - sometimes movement may be observed without touching.


• The 3rd trimester
  This is from week 27 until the baby is born. During this trimester the baby will build up fat stores, and continue growing rapidly. The baby's lungs will develop, as will his/her sense of hearing, taste and sight. The mother may experience backache and find it harder to get into the right position for a good night's sleep. The mother will also be urinating more often as the baby and everything around him/her presses against her bladder. She may also experience contractions that take place many days or weeks before the birth - they are called Braxton Hicks contractions - these are not the contractions of labor.

Antenatal care

A team of health care professionals are involved in helping the mother and baby through the 9 months of pregnancy. They include GPs, midwives, and obstetricians - they may also include nutritionists and physical therapists. Antenatal care is all about monitoring the progress of the baby and mother. In the UK there are usually about 10 antenatal appointments for a mother's first baby, and about 7 for subsequent pregnancies.

The first antenatal appointment usually takes place within the first 12 weeks of pregnancy. A doctor or midwife will talk to the mother about her general health, and also find out whether there are health issues that may need additional treatment or care. The mother will also be informed about other pregnancy care services in her area, as well as any benefits she is entitled to from the state. Advice will also be ongoing regarding lifestyle and diet. The mother's bodyweight will be measured - if she is seriously over- or underweight she will be offered additional care. They will also check her blood pressure and test her urine for protein. When there is protein in the urine it could indicate a kidney problem, or even diabetes.

Ultrasound scan - this uses sound waves and produces an image of the baby inside the mother. An ultrasound scan will be offered towards the end of the first trimester. The scan can also better predict when the baby is likely to be born. The mother will also know whether she is carrying just one baby, or more. Another scan will be offered between 18 to 20 weeks - this second scan can confirm whether the baby is developing normally. In the UK, and most other countries, the mother does not have to have a scan if she does not want to.

The following tests will also be offered, the mother can refuse them, however, they may help detect possible conditions, most of them treatable, which may affect the health of the mother or the baby:

• Anemia (deficiency of red blood cells) - a mother's iron requirement increase considerably when she is pregnant. Iron is crucial for the production of hemoglobin, the protein in red blood cells that carries oxygen to other cells. The amount of blood in a pregnant woman can be nearly 50% higher than normal. She will need more iron to make more hemoglobin. She will also need more iron for the baby and the placenta.


• Down's syndrome - the risk of having a baby with Down's syndrome increases with age. For a woman in her 20s the risk is 1 in 1,500, in her 30s 1 in 800, at 35 it is 1 in 270, at 40 it is 1 in 100, and at 45 it is 1 in 50. Screening can be done to find out whether the baby has Down's syndrome.


• Hepatitis B - infection with hepatitis B virus is a problem for the pregnant mother. The risk is not only for herself, but also for the baby as she might pass the virus to the baby. In the USA approximately 1 in every 500 to 1,000 pregnant women has hepatitis when she gives birth. The incidence could be higher because many women who are infected show no signs.


• Migraine - women who suffer from migraines should tell their doctors. A growing number of doctors are becoming aware of the effect migraines may have on pregnancy. A study found that migraine sufferers have a higher risk of stroke, heart disease, blood clots and hypertension during pregnancy.


• Gestational diabetes - a number of women develop diabetes during their pregnancy. It has very few symptoms and is most commonly diagnosed through screening during the pregnancy.


• HIV - a woman who is infected with HIV risks passing the virus on to her baby during pregnancy, during labor and delivery, and also through breastfeeding. If the infected mother takes no preventive drugs and also breastfeeds there is a 20% to 45% chance of infecting the baby. Modern drugs can effectively prevent HIV transmission from mother to baby during pregnancy, labor and delivery.


• Rubella (German measles) - the risk of being exposed to rubella during pregnancy in most developed countries is very small. However, the mother needs to know whether she is immune. If a mother becomes infected during early pregnancy it could be devastating for the baby. The risk of miscarriage would be high, and the baby could be born with multiple birth defects and developmental problems.


• Syphilis - this is a fairly easy sexually transmitted disease to cure. Syphilis can seriously harm both the mother and the baby if untreated.

Antenatal classes

These classes are aimed at helping the mother prepare for the birth. They should inform her about what to expect during labor and delivery, what pain relief and delivery options there are, how to keep herself physically fit, how to care for her infant, relaxation techniques, and what common emotions are frequently experienced by mothers during pregnancy, labor and delivery, and afterwards. In the UK and many other countries there are special antenatal classes for mothers who are carrying more than one baby.

Complications during pregnancy

The following conditions are commonly experienced by mothers during their pregnancy:

• Anemia
• Constipation
• Genital infections
• Hemorrhoids
• Hypertension (high blood pressure)
• Hypotension (low blood pressure)
• Gum disease
• Nausea and vomiting
• Urinary tract infections
• Heartburn
• Moodiness

The following are complications of pregnancy:

• Miscarriage - about 25% of all pregnancies in the UK end in miscarriage. The majority of miscarriages happen during the first trimester. Most women notice vaginal bleeding as the first indication, occasionally accompanied with abdominal pain, or backache. Many women describe the pain as similar to menstrual pains. Vaginal bleeding does not necessarily mean a miscarriage will happen.


• Ectopic pregnancy - this is when the zygote is implanted somewhere else, not in the lining of the uterus. This is a potentially fatal condition for the mother because it can cause serious internal bleeding. Symptoms may include pain at the tip of the shoulder, vaginal bleeding, pain on one side of the abdomen, pain when urinating or passing stools.


• Pre-eclampsia - this term refers to hypertension (high blood pressure) either during the pregnancy or just after delivery. The woman's blood pressure rises, there is protein in her urine, and she has edema (fluid retention). The woman's face, hands, feet, and ankles may swell. She may gain weight rapidly, have vision problems, abdominal pain and headaches. In the UK approximately 10% of pregnant women develop pre-eclampsia. Most cases are easy to treat. For some, it can be severe. Pre-eclampsia usually occurs during the third trimester. A study found that women who experience pre-eclampsia during pregnancy have more heart attacks, strokes and blood clots later in life than women without the condition.


• Placenta previa - the placenta covers part of the cervix, and sometimes all of it. The cervix is the exit from the uterus, where the baby will come through when he/she is born. Some women with placenta previa bleed. If it continues blocking the cervix the baby will have to be delivered by cesarean section. Most cases of placenta previa sort themselves out before the baby is born.


• Obstetric cholestasis - bile builds up in the blood. It is a rare condition, but can cause serious complications, such as a premature birth.


• Molar pregnancy - this is also uncommon. The sperm fertilized the egg, but the zygote does not become an embryo because of some genetic anomaly. However, the placenta continues to develop and the pregnancy hormone HCG continues to be present in the blood at a very high level. All molar pregnancies end up in miscarriage. Most cases are detected either by ultrasound or following tests after the mother reports bleeding.


• Stillbirth - a stillborn baby is one who is born after 24 weeks of pregnancy but shows no signs of life after delivery.

Steps for the best pregnancy

There are some things the mother can do to reduce risks of complications for her and her baby:

• Physical Activity - Most pregnant women should do some kind of moderate exercise. Not only does exercise help in general health and bodyweight control, it also prepares the mother for a more successful labor and delivery.
  
  What sort of exercise is done depends on the mother and how her pregnancy is progressing. Midwives and doctors should be consulted regarding any exercise program. Some exercises, such as contact sports, should be avoided. An interesting study found that pregnant mothers who did do exercise spent less time watching TV or using a computer at home, compared to pregnant mothers who did now exercise - even though most who did no exercise said they did not have time.


• Maintaining good bodyweight - a study found that babies born to obese mothers may have an increased risk of asthma. Doctors used to advise all women to gain weight during pregnancy. However, n new research says obese women should not gain weight during pregnancy.


• Stop smoking - a pregnant mother who smokes regularly significantly increases the chances of having an underweight or premature baby. A study found that women who smoke during pregnancy risk delivering aggressive kids. Another study found that mothers who smoke early in pregnancy are more likely to give birth to infants with heart defects.


• Alcohol consumption - the consumption of alcohol while pregnant can harm the baby. A study showed that pregnant women who binge drink early in their pregnancy increase the likelihood that their babies will be born with oral clefts.


• Marijuana/cannabis - both marijuana and cannabis might have harmful effects on the unborn baby. Experts are not sure what the effects might be.


• Overworking - a study found that too much work can cause pregnancy problems.


• Medications - a pregnant mother should only take medicines that her doctor has prescribed or allowed.


• Complementary medicines - an expectant mother should not assume an alternative therapy is safe just because it is natural.


• Avoid air pollution - a new study found that the growth of the fetus may be affected if the mother is exposed to air pollution. Avoiding air pollution is hard if the mother lives in a highly polluted area - however, certain strategies may help, such as opening windows on the side of the house with less pollution coming in, going to the shops, etc., at certain times of day, and avoiding certain streets.


• Some types of fish - some types of fish have high levels of mercury, especially shark, marlin, swordfish and barracuda. Tuna fish from some parts of the world may have mercury - as of June 2009 it appears that tuna from Spain is the safest. The UK Department of Health recommends a maximum intake of 2 tuna steaks or 4 medium-sized cans of tuna per week.


• Diet - a pregnant mother should follow a healthy and balanced diet that must include plenty of fruits, vegetables, whole grains. Several studies have shown that eating fish is good for the mother and baby. Fluid intake should be increased to at least two liters per day. Not only will fluids help get rid of toxins and waste more effectively, they will also help prevent nausea and constipation.


• Caffeine - a pregnant mother should avoid, or at least cut down, on her caffeine intake. A study found that consuming caffeine at any time during pregnancy is associated with an increased risk of fetal growth restriction (low birth weight).


• Vitamins and supplements - only take what the doctor or midwife advise you to. Folic acid is usually recommended as this lowers the risk of neural tube defects (e.g. spina bifida) for the baby. In the UK the National Health Service recommends 400 micrograms of folic acid per day as soon as a woman thinks she may be pregnant (or when she begins trying for a baby). In fact, a study found that women who take folic acid for one year before they become pregnant significantly reduce the risk of premature birth. You should not take vitamin A supplements.


• Avoiding bacterial infections from food - measures need to be taken to avoid infection from salmonella or listeriosis, which could harm the baby. The following foods should be avoided by pregnant women, according to the National Health Service, UK:
  
  
  • Cheeses that have been ripened with mould, these include Brie, Camembert, and blue-veined cheese.
  
  
  • Pate. This also includes vegetable pates.
  
  
  • Undercooked ready-prepared meals.
  
  
  • Uncooked foods which are usually consumed cooked, such as steak tartar.
  
  
  • Raw eggs, mayonnaise with raw eggs.
  
  
  • Some cured meats which have not been cooked - salami, for example, may increase a pregnant woman's risk of developing toxoplasmosis, an infection that can harm the unborn baby.
  
  The pregnant mother should make sure she washes her hands before handling food, as well as washing all fruit and vegetables before consuming them. In fact, this practice is recommended for people who are not pregnant too.


• Gardening - there are infections that can be picked up from soil and some animal feces. Wearing gloves and washing hands before and after gardening helps protect the pregnant mother from becoming infected.


• Cat feces - cat feces can cause toxoplasmosis, which may affect the baby. A pregnant woman should avoid all contact with cat feces, cat litters and feces in soil.

Written by Christian Nordqvist

Original article date: 24 Feb 2006
Article updated: 04 June 2009

Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today