(19) Pregnant Woman Flashcards
Pregnancy Hormonal Changes:
Estrogen
- promotes endometrial growth that supports the early embryo
- stimulates marked enlargement of the pituitary gland (by up to 135%) and increased prolactin output from its anterior lobe, which readies breast tissue for lactation
- contributes to the hypercoagulable
state that puts pregnant women at four to five times higher risk for thromboembolic events, primarily in the venous system
Pregnancy Hormonal Changes:
Progesterone
- levels increase throughout pregnancy, leading to increased tidal
volume and alveolar minute ventilation, though respiratory rate remains constant; respiratory alkalosis and subjective shortness of breath result from these changes - Lower esophageal sphincter tone resulting from rising levels
of estradiol and progesterone contributes to gastroesophageal reflux - relaxes tone in the ureters and bladder, causing hydronephrosis (in
the right ureter more than the left) and an increased risk of bacteriuria
Pregnancy Hormonal Changes:
HCG
- has five variant subtypes
- Two are produced by the placenta and support progesterone synthesis in the corpus luteum, stabilizing the endometrium and effectively preventing loss of the early embryo to menstruation
- Serum and urine pregnancy assays test primarily for the two pregnancy-related HCG variants; three isoforms are produced by different cancers and the pituitary gland
Pregnancy Hormonal Changes:
Placental Growth Hormone
- influences fetal growth and the development of preeclampsia
- implicated in insulin resistance after midpregnancy and in gestational diabetes, which carries a lifetime risk of progressing to type 2 diabetes of up to 60%
Pregnancy Hormonal Changes:
Thyroid function
- changes include an increase in thyroid-binding globulin due
to rising levels of estrogen and stimulation of thyroid-stimulating hormone (TSH) receptors by HCG - results in a slight increase, usually in the normal range, in serum concentrations of free T3 and T4, while serum TSH concentrations appropriately decrease
- This transient apparent “hyperthyroidism” should be considered physiologic.
Pregnancy Hormonal Changes:
relaxin
secreted by the corpus luteum and placenta and is involved in the
remodeling of reproductive tract connective tissue to facilitate delivery, increased
renal hemodynamics, and increased serum osmolality. Despite its
name, relaxin does not affect peripheral joint laxity during pregnancy. Weight
gain, especially around the gravid uterus, and shifts in the center of gravity
contribute to lumbar lordosis and other musculoskeletal strain.
Pregnancy Hormonal Changes:
Erythropoietin
increases during pregnancy, which raises erythrocyte mass.
Plasma volume increases to a greater extent, causing relative hemodilution
and physiologic anemia, which can protect against blood loss during birth.
Cardiac output increases but systemic vascular resistance decreases, resulting
in a net fall in blood pressure, especially during the second trimester and
returning to normal by the third trimester.
Pregnancy Hormonal Changes:
Basal Metabolic Rate
increases 15% to 20% during pregnancy, increasing daily
energy demands by an estimated 85, 285, and 475 kcal/d in the first, second,
and third trimesters, respectively.
Pregnancy Anatomic Changes:
Breasts
breasts become moderately enlarged due to hormonal
stimulation that causes increased vascularity and glandular hyperplasia. By the
third month of gestation, the breasts become more nodular. The nipples become
larger and more erectile, with darker areolae and more pronounced Montgomery
glands. The venous pattern over the breasts becomes visibly more prominent as
pregnancy progresses. In the second and third trimesters, some women secrete
colostrum, a thick, yellowish, nutrient-rich precursor to milk. Breast tenderness
may make them more sensitive during examination.
Pregnancy Anatomic Changes:
uterus
Muscle cell hypertrophy, increases in fibrous and elastic tissue, and
development of blood vessels and lymphatics all contribute to growth of the uterus.
The uterus increases in weight from ∼70 g at conception to almost 1,100 g at
delivery, when it accommodates from 5 to 20 L of fluid.1 In the first trimester, the
uterus is confined to the pelvis and shaped like an inverted pear; it may retain its
prior anteverted (forward-leaning), retroverted (backward-leaning), or retroflexed
(backward-bent) position. By 12 to 14 weeks, the gravid uterus becomes externally
palpable as it expands into a globular shape beyond the pelvic brim.
Beginning in the second trimester, the enlarging fetus pushes the uterus into an
anteverted position that encroaches into the space usually occupied by the bladder,
triggering frequent voiding. The intestines are displaced laterally and superiorly.
The uterus stretches its own supporting ligaments, causing “round ligament
pain” in the lower quadrants. Often, slight dextrorotation to accommodate the
rectosigmoid structures on the left side of the pelvis leads to greater discomfort
on the right side as well as increased right-sided hydronephrosis.1 Growth patterns
of the gravid uterus are shown in Figure 19-4. Sagittal depictions of the
gravid abdomen during each trimester appear in Figures 19-5 to 19-7.
Pregnancy Anatomic Changes:
Vagina
Increased vascularity throughout the pelvis gives the vagina a bluish
color, known as Chadwick sign. The vaginal walls appear deeply rugated due to
thicker mucosa, loosening of connective tissue, and hypertrophy of smooth
muscle cells. Normal vaginal secretions may become thick, white, and more
profuse, known as leukorrhea of pregnancy. Increased glycogen stores in the
vaginal epithelium give rise to a proliferation of Lactobacillus acidophilus, which
lowers the vaginal pH. This acidification protects against some vaginal infections,
but at the same time, increased glycogen may contribute to higher rates of vaginal
candidiasis.
Pregnancy Anatomic Changes:
Cervix
At ∼1 month after conception,
the cervix softens and also turns bluish or
cyanotic in color, reflecting the increased
vascularity, edema, and glandular hyperplasia
throughout the cervix.1 Hegar sign is the
palpable softening of the cervical isthmus,
the portion of the uterus that narrows into
the cervix, illustrated in Figure 19-8. This
cervical remodeling involves rearrangement
of the cervical connective tissue that decreases
collagen concentration and facilitates dilatation
during delivery. Copious cervical secretions
fill the cervical canal soon after
conception with a tenacious mucus plug that
protects the uterine environment from
outside pathogens and is expelled as bloody
show at delivery.
Pregnancy Anatomic Changes:
Adnexae
Early in pregnancy, the corpus luteum, which is the ovarian follicle
that has discharged its ovum, may be prominent enough to be felt on the affected
ovary as a small nodule; this disappears by
midpregnancy.
Pregnancy Anatomic Changes:
External Abdomen
As the skin
over the abdomen stretches to ac commodate
the fetus, purplish striae gravidarum
or “stretch marks” and a linea nigra, a
brownish black pigmented vertical stripe
along the midline skin, may appear
(Fig. 19-9). As tension on the abdominal
wall increases with advancing pregnancy,
the rectus abdominis muscles may separate
at the midline, called diastasis recti. If
diastasis is severe, especially in multiparous
women, only a layer of skin, fascia, and
peritoneum may cover the anterior uterine
wall, and fetal parts may be palpable
through this muscular gap.
Common Concerns in Pregnancy:
Amenorrhea
all trimesters
High levels of estrogen, progesterone, and HCG build up the endometrium and prevent
menses, causing missed periods which are often the first noticeable sign of
pregnancy
Common Concerns in Pregnancy:
Heartburn
all trimesters
Progesterone relaxes the lower esophageal sphincter, allowing gastric contents to
reflux into the esophagus. The gravid uterus also exerts physical pressure against
the stomach, contributing to reflux symptoms
Common Concerns in Pregnancy:
Urinary Frequency
all trimesters
Increases in blood volume and filtration rate through the kidneys result in increased
urine production, while pressure from the gravid uterus reduces potential space for
the bladder. Dysuria or suprapubic pain should be investigated for urinary tract
infection
Common Concerns in Pregnancy:
Vaginal discharge
all trimesters
Asymptomatic milky white discharge, leukorrhea, results from increased secretions
from vaginal and cervical epithelium due to vasocongestion and hormonal changes.
Any foul-smelling or pruritic discharge should be investigated.
Common Concerns in Pregnancy:
Constipation
all trimesters
Constipation results from slowed gastrointestinal transit due to hormonal changes,
dehydration from nausea and vomiting, and the supplemental iron in prenatal
vitamins
Common Concerns in Pregnancy:
Hemorrhoids
all trimesters
Hemorrhoids may be caused by constipation, decreased venous return from increasing
pressure in the pelvis, compression by fetal parts, and changes in activity level
during pregnancy.
Common Concerns in Pregnancy:
Backache
all trimesters
Hormonally induced relaxation of the pelvic ligaments contributes to musculoskeletal
aches. Lordosis required to balance the gravid uterus contributes to lower back
strain. Breast enlargement may contribute to upper backaches.
Common Concerns in Pregnancy:
N/V
1st trimester
This is poorly understood but appears to reflect hormonal changes, slowed gastrointestinal
peristalsis, alterations in smell and taste, and sociocultural factors. Hyperemesis
gravidarum is vomiting with weight loss of >5% of prepregnancy weight.
Common Concerns in Pregnancy:
Breast tenderness/tingling
1st trimester
Pregnancy hormones stimulate the growth of breast tissue, which causes swelling and
possible aching, tenderness, and tingling. Increased blood flow can make delicate
veins more visible beneath the skin.
Common Concerns in Pregnancy:
fatigue
1st/3rd trimester
Fatigue is related to the rapid change in energy requirements, sedative effects of progesterone,
changes in body mechanics due to the gravid uterus, and sleep disturbance.
Many women report increased energy and well-being during the second
trimester
Common Concerns in Pregnancy:
lower abdominal pain
2nd trimester
Rapid growth in the second trimester causes tension and stretching of the round ligaments
that support the uterus, causing sharp or cramping pain with movement or
position change.
Common Concerns in Pregnancy:
abdominal striae
2nd or 3rd trimester
Stretching of the skin and tearing of the collagen in the dermis contribute to thin,
usually pink, bands, or striae gravidarum (stretch marks). These may persist or fade
over time after delivery
Common Concerns in Pregnancy:
Contractions
3rd trimester
Irregular and unpredictable uterine contractions (Braxton Hicks contractions) are rarely
associated with labor. Contractions that become regular or painful should be evaluated
for onset of labor.
Common Concerns in Pregnancy:
Loss of mucus plug
3rd trimester
Passage of the mucus plug is common during labor but may occur prior to the onset of
contractions. As long as there are no regular contractions, bleeding, or loss of fluid,
loss of the mucus plug is unlikely to trigger the onset of labor.
Common Concerns in Pregnancy:
Edema
3rd trimester
Decreased venous return, obstruction of lymphatic flow, and reduced plasma colloid
oncotic pressure commonly cause lower extremity edema. However, sudden severe
edema and hypertension may signal preeclampsia.
Pregnancy:
Common Concerns
● Initial prenatal history
● Confirmation of pregnancy
● Symptoms of pregnancy
● Concerns and attitudes toward the pregnancy
● Current health and past clinical history
● Past obstetric history
● Risk factors for maternal and fetal health
● Family history of patient and father of the newborn
● Plans for breastfeeding
● Plans for postpartum contraception
● Determining gestational age and expected date of delivery