Signs of pregnancy
presumptive (subjective signs) Amenorrhea, nausea, vomiting, increased urinary frequency,
excessive fatigue, breast tenderness, quickening at 18–20 weeks
probable (objective signs) Goodell sign (sof
...
Signs of pregnancy
presumptive (subjective signs) Amenorrhea, nausea, vomiting, increased urinary frequency,
excessive fatigue, breast tenderness, quickening at 18–20 weeks
probable (objective signs) Goodell sign (softening of cervix)
Chadwick sign (cervix is blue/purple)
Hegar’s sign (softening of lower uterine segment)
Uterine enlargement
Braxton Hicks contractions (may be palpated by 28 weeks)
Uterine soufflé (soft blowing sound due to blood pulsating through the placenta)
Integumentary pigment changes
Ballottement, fetal outline definable, positive pregnancy test (could be hydatidiform mole,
choriocarcinoma, increased pituitary gonadotropins at menopause)
positive (diagnostic signs) Fetal heart rate auscultated by fetoscope at 17–20 weeks or by Doppler at
10–12 weeks
Palpable fetal outline and fetal movement after 20 weeks
Visualization of fetus with cardiac activity by ultrasound (fetal parts visible by 8 weeks)
Pregnancy and fundal height measurement
Signs of pregnancy (presumptive, probable, positive)
Pregnancy and fundal height measurement As pregnancy progresses, the
fundus rises out of the pelvis (Figure 29-1). At 12 weeks’ gestation, the fundus is
located at the level of the symphysis pubis. By week 16, it rises to midway between
symphysis pubis and the umbilicus. By 20 weeks’ gestation, the fundus is typically at the
same height as the umbilicus. Until term, the fundus enlarges approximately 1 cm per
week. As the time for birth approaches, the fundal height drops slightly. This process,
which is commonly called lightening, occurs for a woman who is a primigravida around
38 weeks’ gestation but may not occur for the woman who is a multigravida until she
goes into labor
Naegele’s rule
Add seven days to the first day of your LMP and then subtract three months. For
example, if your LMP was November 1, 2017: Add seven days (November 8, 2017).
Subtract three months (August 8, 2017).
The EDD is calculated by adding seven days to the first day of the last menstrual period, subtracting
three months and adding one year.
This formula is known as Naegele's Rule. For example, if the patient's last menstrual period, LMP,
was on August 10, 2019, the EDD would be calculated as follows. LMP equals August 10, 2019 plus
seven days. August 17, 2019, minus three months. May 17, 2019 plus one year and that equals May
17, 2020.
Hematological changes during pregnancy
During pregnancy, the heart is displaced upward and to the left within the chest cavity
by the gravid uterus’s pressure on the diaphragm. As pregnancy progresses, the risk for
inferior vena cava and aortic compression leading to supine hypotension increases
when the woman lies in a supine position. To avoid hypotension and potential syncope,
the woman should be advised to lie in a left lateral position. Hemodynamic changes and
anatomic changes also may alter vital signs in the pregnant woman (Table 29-2).
Cardiac output in pregnancy increases by 30% to 50% over that in women who are not
pregnant (Blackburn, 2013; Ouziunian & Elkayam, 2012). This increase
peaks in the early third trimester and is maintained until birth. Half of the total increase
in cardiac output, however, occurs by the eighth week of pregnancy (Blackburn,
2013). Therefore, women with cardiac disease may become symptomatic during the
first trimester. Stroke volume is also increased during pregnancy by 20% to 30%. These
increases in cardiac output and stroke volume allow for the 30% increase in oxygen
consumption observed during pregnancy.
TABLE 29-2 Vital Sign Changes in Pregnancy
Vital Sign Changes in Pregnancy Measurement Alterations in
Pregnancy
Heart rate
and heart
sounds
Volume of the first heart sound
may be increased with splitting.
Third heart sound may be
detected.
Systolic murmurs may be detected.
Increases by 15–20 beats/min by
32 weeks’ gestation.
Palpate the maternal pulse when
auscultating the fetal heart rate to
be able to distinguish between the
two.
Respiratory
rate
Increases by 1–2 breaths/min None
BP First trimester: same as
prepregnancy values
Second trimester: systolic BP
decreases by 2–8 mm Hg and
diastolic BP decreases by 5–15 mm
Hg due to peripheral vascular
resistance
Third trimester: gradually returns to
prepregnancy values
Use of an automated cuff may
improve accuracy of
measurement, as some pregnant
women do not have a fifth
Korotkoff sound.
Systolic and diastolic BP may be
16 mm Hg higher when taken
while the woman is sitting.
BP readings may decrease in the
maternal left lateral position.
Abbreviation: BP, blood pressure.
Data from Jarvis, C. (2016). Physical examination and health assessment (7th ed.). St. Louis, MO:
Saunders Elsevier; Ouziunian, J., & Elkayam, U. (2012). Physiologic changes during normal
pregnancy and delivery. Cardiology Clinics, 30, 317–329; Tan, E., & Tan, E. (2013). Alterations in
physiology and anatomy during pregnancy. Best Practice & Research Clinical Obstetrics &
Gynaecology, 27, 791–802.
During pregnancy, blood volume increases by 30% to 50%, or 1,100 to 1,600 mL
(Ouziunian & Elkayam, 2012), and peaks at 30 to 34 weeks’ gestation. The
increase in blood volume improves blood flow to the vital organs and protects against
excessive blood loss during birth. Fetal growth during pregnancy and newborn weight
are correlated with the degree of blood volume expansion.
Of the blood volume expansion occurring during pregnancy, 75% is considered to be
plasma (King et al., 2015). There is also a slight increase in red blood cell volume
(RBC). The blood volume changes result in hemodilution, which leads to a state of
physiologic anemia during pregnancy. As the RBC volume increases, iron demands also
increase. Leukocytosis occurs in pregnancy, with white blood cell counts increasing to
as much as 14,000 to 17,000 cells per mm3 of blood (Table 29-3). Clotting factors
increase as well, creating a risk for clotting events during pregnancy.
Systemic vascular resistance is reduced due to the effects of progesterone,
prostaglandins, estrogen, and prolactin. This lowered systemic vascular resistance, in
combination with inferior vena cava compression, is partly responsible for the
dependent edema that occurs in pregnancy. Epulis of pregnancy, or hypertrophy of the
gums accompanied by bleeding, may also occur and is due to decreased vascular
resistance and increase in the growth of capillaries during pregnancy (Jarvis, 2016).
Indications and contraindications for prescribing combined estrogen
vs. progesterone-only birth control
Progestin-only contraceptives are used continuously; there is no hormone-free interval,
as occurs with combined methods. These contraceptive methods have minimal effects
on coagulation factors, blood pressure, or lipid levels and are generally considered safer
for women who have contraindications to estrogen, such as cardiovascular risk factors,
migraine with aura, or a history of VTE. In spite of this belief, the product labeling fo
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