Pregnancy Overview

Pregnancy refers to the state when a woman carries a fetus or embryo in her uterus or womb. It happens when a woman’s egg cell is fertilized by a man’s sperm cell. Pregnancy usually lasts 40 weeks from the time of fertilization, which is about 40 weeks from the last menstrual period. Thus, the estimated date of delivery (EDD) can be determined by counting 280 days from the first day of the last menstrual period. However, there have been cases where a baby is born prematurely. This can happen anywhere from 32 to 37 weeks of gestation.

Symptoms and Diagnosis

The symptoms associated with pregnancy generally occur during the first few weeks after the baby has been conceived. Pregnancy symptoms typically include nausea and/or vomiting, tenderness in the breasts, an abnormal menstrual period or skipping the menstrual period altogether, enlargement of the breasts, darkening of the nipples, gaining weight, and more frequent urination than usual.

Implantation bleeding may be observed three or four weeks since the last menstrual period. This is caused by the implantation of the embryo in the woman’s uterus. Another sign of pregnancy is increase in body temperature. Human chorionic gonadotropin (hCG) is also detected in the woman’s urine and blood samples. In the later stages of pregnancy, the woman may start to feel the movement of the fetus in her womb.

Related Changes

The woman’s body, as it adjusts to the presence of the fetus, experiences many physiological changes in the different stages of pregnancy. The changes become more pronounced as the fetus continues to grow more and more each day.

Physical
The most obvious physical change is weight gain. The woman gains weight as her appetite increases. The weight of the growing fetus also contributes to her total body weight. Additional weight gain is caused by more water retention and more blood volume. A pregnant woman can gain 5 to 100 pounds during her entire term, although the recommended weight gain for a woman with ideal weight is only 25 to 35 pounds.

Hormonal

Pregnancy greatly affects a woman’s hormonal levels. The estrogen and progesterone levels undergo frequent increases throughout the pregnancy, resulting in the temporary halting of the menstrual cycle.

The woman’s pituitary gland enlarges by up to 50%, causing an increase in the level of the enzyme prolactin, a hormone associated with lactation. This results in the shift of ductal mammary gland structure to lobular-alveolar. The level of the parathyroid hormone also rises as the absorption of calcium in the intestine becomes greater and the calcium gets reabsorbed in the kidneys.

The woman’s body begins to conserve blood glucose in order to make it available for the fetus. This is achieved as the placenta produces placental lactogen. This hormone is also responsible for decreasing the woman’s sensitivity to insulin, a condition that results in gestational diabetes.

Cardiovascular

During the first two trimesters of pregnancy, the woman’s blood volume rises by up to 40%. This is caused by increased levels of aldosterone, which in turn results in increased volume of plasma. The number of red blood cells also rises because of increased levels of erythropoietin.

The pregnant woman’s heart rate increases. Likewise, her blood pressure rises and falls depending on the stage of pregnancy she is in. Generally, during the first trimester, blood pressure falls.

Other changes (respiratory, metabolic, renal)

There are other changes that a pregnant woman experiences as she goes through the entire process. For example, her body’s oxygen requirement is greater than pre-pregnancy days. The respiration rate also increases. Furthermore, the pregnant woman’s body needs more nutrients because of the growth of the fetus.

Nutritional Needs

A pregnant woman needs to eat balanced meals every day. Her diet should consist of the proper portions of carbohydrates, fats, proteins, and fruits and vegetables. A pregnant woman is generally advised to take folic acid. This is to avoid defects on the neural tube, which starts to develop during the first month of pregnancy. Folate can be obtained from green vegetables, spinach, and citrus fruits.

To ensure the fetus’ healthy development, the pregnant woman should take in the required micronutrients for the fetus’ growth. For example, vitamin D and calcium are both essential for the development of the fetus’ bones. Care should be taken to avoid bacterial and parasitic infection. The pregnant woman should make sure that the food she eats is clean and safe. This is because she is more prone than others to Salmonella infection; thus, eggs and poultry should be completely cooked before she eats them.

Characteristics

Pregnancy is divided into three stages — the first trimester, the second trimester, and the third trimester.

First trimester

The first trimester covers the entire process from fertilization to the third month of pregnancy. Many women may experience cramps during this stage, although this should not be cause for alarm unless the cramps are accompanied by bleeding or spotting. The placenta is formed during the first trimester. The placenta is the structure through which nutrients are transported from mother to fetus. Morning sickness is experienced by 70% of pregnant women at this stage. This eventually improves during the later stages of pregnancy. Many miscarriages happen during the first trimester.

Second trimester

The second trimester refers to the fourth, fifth, and sixth months of pregnancy. During this stage, the pregnant woman has usually gotten over morning sickness and has adjusted to the pregnancy. She also starts to gain weight. Generally, at this stage, the woman begins to feel the movements of the fetus. However, some women don’t get to experience this until the later stages of pregnancy, and this is normal. At this point, the placenta is fully developed. The fetus is also producing its own insulin and is already releasing urine. The sex of the fetus — whether it is a boy or a girl — can be determined during the second trimester.

Third trimester

This is the stage when pregnant women gain the most weight. The fetus is growing fast and gaining at least 28 grams of weight each day. It also begins to prepare itself for birth by shifting to a downward position. At this point, the mother can easily feel the movements of the baby in her womb. A premature baby has a great chance of surviving when born during the third trimester. Of course, this is achieved with the help of modern technology and specialized medical equipment.

Warning Signs

There are some warning signs to watch out for. These are conditions that may indicate serious problems in pregnancy. A pregnant woman with these symptoms or conditions should seek professional medical treatment as soon as possible.

• Presence of leaking fluid, which indicates ruptured membranes
• Vaginal pain
• Abdominal pain
• Extremely high blood pressure reaching 140/90
• Vaginal bleeding
• Sudden weight gain
• Impairment of vision
• Intense headache
• Intense chest pain
• Fainting or the feeling of being about to faint
• Gray, white, or pink vaginal discharge
• Bloody vaginal discharge
• Experiencing seizure even without a history of this condition

High-Risk Pregnancies

There are also conditions in pregnancy that should be watched out for. A woman with high-risk pregnancy is someone who has a great probability of experiencing pregnancy complications. This is usually true for women with high blood pressure and women with diabetes. Many women who get pregnant after the age of 35 may experience certain complications brought about by age, and teenagers who get pregnant may also face some complications because their bodies are not fully developed for childbirth.