Normal Pregnancy in a Female
William Carey University
Dr. Robin C. Dennis
The pathology of pregnancy is a long, complex process that involves the fertilization of an ovum and its growth into a fetus. Pregnancy introduces a variety of hormonal changes to the human body, so it is important to understand how this process and these physiological changes affect women and the developing fetus. A typical pregnancy lasts about nine months, and it is important that pregnant women understand pregnancy and what goes on during each phase of the process. In addition, the female body and the developing embryo are susceptible to a range of health issues, so a number of complications can occur between conception and birth. By equipping patients with accurate information and helping them understand the process of pregnancy, as well as potential risks and complications, nurses can help patients become more aware of their body, the one developing in them, and the decisions that they make leading up to childbirth. Background
A large number of the risks and complications associated with pregnancy are greatest from seventeen to fifty six days after conception, “before [the] first obstetric visit, and before many women know they are pregnant” (‘Preconception’, 2009). As a result, issues that can be minimized or prevented often become larger problems in the later stages of pregnancy. For this reason, it is suggested that couples use a form of contraception to plan ahead and prevent unexpected pregnancy. This planning “facilitate[s] [the] desired timing of pregnancy” and helps couples consider other factors such as “maternal age and interpregnancy interval,” which are both important for determining the risks and complications that may occur during pregnancy (‘Preconception’, 2009). In addition, tracking menstrual cycles also helps couples more accurately determine the date of conception and “encourages prenatal care” (‘Preconception’, 2009). It should be noted, however, that no studies have proven preconception care to reduce and/or prevent complications that may occur later in a later phase of pregnancy. Planning pregnancy and accurately tracking the date of conception, though, makes patients more likely to receive early prenatal care, which can help reduce some of the stress and anxiety that women experience while pregnant (‘Preconception’, 2009) Physiological Changes in a Normal Pregnancy
As mentioned previously, pregnancy brings the onset of several major physiological changes in the female body. Women experience several symptoms or “presumptive signs” that may be indicators of pregnancy (Jarvis, 2012, p. 824). Several of these presumptive signs include “amenorrhea, breast tenderness, nausea, fatigue, and increased urinary frequency” (Jarvis, 2012, p. 824). In addition to presumptive signs, women also experience “positive signs of pregnancy” (Jarvis, 2012, p. 824), which are direct causes of pregnancy and more accurate indicators. These changes usually take place in major organ systems. According to Luks (2011) the major organ systems affected are as follows: 1. Cardiovascular, 2. Respiratory, 3. Gastrointestinal, 4. Renal, 5. Hematologic (p. 93). Each of these organ systems experience major changes as a result of pregnancy. For instance, there is "[around a] 40% increase in cardiac output and circulating blood volume [in pregnant women]” (Luks, 2011, p. 90). This takes place during the first trimester, but it continues throughout pregnancy and spikes during the third trimester. This change in the cardiovascular system is normal and is handled well by most women; however, it can cause problems in women with cardiovascular issues, such as “valvular lesions … [and] pulmonary hypertension” (Luks, 2011, p. 90). Much like the cardiovascular system, the respiratory system experiences “minute ventilation increases[,] … [which eventually] reach levels [of] 30%-50% greater than the non-pregnancy baseline” (Luks, 2011, p. 91). The hematologic system undergoes increases in “red blood cell mass … [by] 15%-30%, … [and] plasma volume expands[,] [while] hemoglobin concentration and hematocrit fall” (Luks, 2011, p. 92). A recent study from Abduljalil (2012) states that the increase in plasma volume is primarily caused by an increase in body water, which helps plasma settle in the “vascular bed” (p. 373). Gastrointestinal changes include “impaired esophageal sphincter function,” which may cause gastro fluids to enter the lungs; however, results from Abduljalil’s studies in 2012 show that “gastric emptying” does not change in healthy women who are pregnant (p. 377). Last in the major organ systems mentioned, is the renal system, which experiences an increase in blood flow, anywhere from 60% to 80% above baseline (Luks, 2011, p. 92). These changes, in conjunction with other hormonal factors, also cause the renal pelvis to dilate (Luks, 2011, p. 92). In contrast, Abduljalil argues that studies on blood flow to the liver are not always accurate because not much is known and the data on the subject often conflicts (2012, p. 377). As mentioned previously, pregnant women are susceptible to a wide range of health issues; however, all of the changes discussed in this section are common and expected during a normal pregnancy. Stages of Pregnancy
Pregnancy in females occurs sometime after ovulation, when the ovum accepts “viable” sperm. This takes place in the phillopian tube, and the fertilized ovum, or blastocyst, begins to grow (Jarvis, 2012, p. 824). The growth of the blastocyst’s cells progresses quickly and it attaches itself to the uterine wall around day twenty to twenty-four. Once settled, the cells in the outer layer of the blastocyst form into the placenta, which supports serves as an “endocrine organ” to support the growth and development of the fetus throughout pregnancy. The placenta also releases important hormones, which trigger changes in the mother’s body to “prepare [her] for birth and lactation.” Progesterone and estrogen are two hormones that are vital to the developments that take place in the mammary ducts and uterus (Jarvis, 2012, p. 824). According to Jarvis (2013), pregnancy typically lasts “280 days from the first day of the last menstrual period,” or 9 months, which are split into three trimesters (p. 824). First Trimester – Embryonic Period
Fertilization takes place during the first trimester and once the blastocyst attaches itself to the wall of the uterus, progesterone and estrogen are released into the body to prepare for pregnancy. “Nausea … vomiting[,] … low blood sugar, … enlarging [of the] uterus, [mood swings,] and fatigue” (Jarvis, 2012, p. 824) are all symptoms that pregnant women will typically experience in the first trimester. The cause for some of these symptoms is unknown, but many can be attributed to the effects of estrogen and progesterone on the body (Jarvis, 2012, p. 824). Over the course of the first nine weeks, the blastocyst develops into an embryo and eventually becomes a fetus. The placenta grows and continues to release hormones and the woman’s uterus begins to cause push up against the bladder, causing frequent urination. Weight gain around the waistline is also common (Tan, 2008, p. 40). The baby continues to develop and amniotic fluid builds up around it. The umbilical cord is also well developed and circulates blood to the infant. Second Trimester
At around 18 weeks, the fetus has developed. According to Tan (2008), “reflex movements [are formed] that allow your baby’s elbows to bend, legs to kick and fingers to form a fist” (p. 42). Because of this, the woman may experience “quickening” caused by the fetus’s movement (Tan, 2008, p. 42). According to Tan (2008), these movements are quick “flutters” that occur “halfway through pregnancy” (p. 42). They can also be used to determine if the “‘dates’” for the pregnancy are accurate (Tan, 2008, p. 42). A less mature form of breast milk called “colostrum” begins to develop in the woman’s breast, and signs of pregnancy, such as “darken[ed] nipples” begin to appear (Jarvis, 2012, p. 825). Most notably, the blood pressure in the woman drops to its lowest and may cause symptoms of fatigue and light-headedness. This drop in blood pressure is due to the development of the fetus and blood pressure is at its lowest around 20 weeks (Jarvis, 2012, p. 825). Several gastrointestinal changes take place during this time as well; “[i]intestines are … displaced by the growing uterus,” and the increase in progesterone “often cause[es] constipation” (Tan, 2008, p. 42). During this time, the fetus becomes more developed and “[the] arms, hands, fingers, legs, feet and toes will be completely formed” (Tan, 2008, p. 42). Third Trimester
During the third trimester, blood pressure returns to normal pregnant state, the baby is highly developed, and several important physical effects take place in the woman’s body to prepare for labor. According to Tan (2008), during this phase the baby is big enough to be felt through the abdomen and it is responsive to noise. It also develops eyesight, brain and nervous system functions, and movement in the eyelids (p. 43). The woman’s uterus has now shifted above the navel, and other physical changes like stretch marks are visible due to continuous weight gain. By the end of the third trimester, the baby will be fully formed and ready to be born. A few weeks before labor, the head of the fetus “drops” or shifts down the pelvis. Also, the cervix starts thinning out and dilating, and the mucosal plug that was formed in the birth canal begins to shift out as the baby moves down (Jarvis, 2012, p. 826). A woman between 37 and 42 weeks is considered “in term” and will be ready to go into labor. Health Measures
Current State of Weight Management Education
One of the most common health measures that women deal with during pregnancy is weight gain. Studies show that obesity significantly increases the risk of complications during pregnancy. In the United Kingdom, studies show that 18% of pregnant women are obese before pregnancy. This poses serious risks, such as “hypertension[,] … thrombosis[,] … gestational diabetes, … greater risk of infections[,] and delivery complications” (Avery & Brown, 2012, p. 378). It also increases the baby’s risk of developing abnormalities such as “spina bifida and oral clefts” (Avery & Brown, 2012, p. 378-79). For these reasons, it is important that pregnant women are aware of weight management and given accurate information to educate themselves. Recent studies show that most pregnant women do not receive detailed information about “nutrition and exercise” as it pertains to weight gain. According to a recent study by Avery and Brown (2012), “Only 64.3% of women reported that they had received diet and/or exercise advice from a healthcare source” (Avery & Brown, 2012, p. 384). This number is very low when considering the major role that health and weight play in pregnancy. Women are typically only give “dietary leaflets” and the issue of weight management is usually not given as much attention as it should be (Avery & Brown, 2012, p. 384). With this in mind, this section serves as a reminder that pregnancy is a complex process that brings the onset of several major biological and physiological changes. Weight management should be considered as an important component of a normal pregnancy, and although it is not a directly integrated into the process with current literature, its importance should be noted for the purposes of this paper.
This overview of the pregnancy process, the risks and complications, and the brief review on health and weight management are essential topics that should be thoroughly understood by nurses and patients who are expecting or plan to have a child. Pregnancy is a long, complex process that results in a wide range of physical, biological, and emotional changes in women, so it is best to prepare for the process by becoming educated early and possibly considering preconception planning. Proper knowledge and planning ahead are the best ways one can prepare for the long process of pregnancy, and ultimately it is this planning and preparation that helps individuals make responsible decisions throughout pregnancy and up until childbirth.
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