Transcript anatomical and physiological changes during pregnancy

ANATOMICAL AND
PHYSIOLOGICAL
CHANGES
DURING PREGNANCY
PHYSIOLOGICAL CHANGES IN
PREGNANCY
Reproductive organs
I. Uterus:
The muscular organ holding the fetus during
pregnancy, nourishment of the fetus through the
placenta. It is divided into the body (Corpus, and
fundus)and the cervix.
 During pregnancy, the uterus increases in weight
from 60 to 1000g. In size, it changes from 6.5 to 32
cm. In a non pregnant state, the uterus is situated in
the pelvic cavity. During pregnancy, it expands into
the abdominal cavity. In addition to the growing
foetus, uterine expansion is caused by an increase in
connective tissue and in the size and number of blood
vessels supplying the uterus
Uterine change during pregnancy
:
b) Ligamentous supports:
1) Round ligaments are fibrous cords attaching to the uterus
and libia majora During pregnancy, they become
elongated and hypertrophied. They supportthe uterus in its
move from the pelvic cavity into the abdominal cavity.
2) Broad ligaments are large folds of peritoneum separating
the pelvis into the anterior and posterior divisions. The
lower portion of the ligament is known asthe cardinal
ligaments, it attaches the lateral aspect of the uterus to the
supravaginal area of the cervix.
3) Utero sacral ligaments attach the sacrum to the posterior
aspect of the cervix to support the cervix.
c) Cervix:
The portion of the uterus connecting the body of the
uterus and the vagina.
1) The internal os joins the body of the uterus with
the cervix.
2) The external os opens into the vagina.
3) During pregnancy, the cervix is closed. A mucus
plug forms over the cervix ,providing a protective
barrier between the vagina and the uterine
contents.
4) During labour and delivery, the cervix shortens
(or effaces) and widens (or dilates), effectively
disappearing. A 10 cm opening is left between the
uterus and the vagina to allow for passage of the
foetus into the birth canal.
5) If the cervix begins dilating prematurely, it is
sometimes stitched together during the second
trimester, until the foetus in mature. This
procedure is known as a cerclage.
II. Ovaries:
The organs storing ova. Through hormonal
influence , one ovum is developed per month. It
then travels into the fallopian tube and has the
potential to be fertilized. One ovary is located on
either side of the uterus, encased in the posterior
aspect of the broad ligaments.
III. Fallopian tubes:
The ducts bringing mature ova from the ovaries
to the uterus via peristaltic action.
a) The fallopian tubes connect the uterine cavity to
the abdominal cavity, near to the ovary. The
opening at the abdominal site is lined with cilia
to promote the peristalsis necessary to convey the
ovum into the tube.
b) They are situated in the superior margin of the
broad ligaments

IV. Vagina:
The connecting passage between the uterus and
the perineum, serving as the birth canal
a) The anterior borders include the bladder and the
urethra.
b) Laterally, the ureters and broad and round
ligaments lie.
c) Posteriorly, the peritoneum and the rectovaginal
fascia.
RESPIRATORY SYSTEM
During pregnancy, the body is in a state of
hyperventilation due to high level of
progesterone.
a. Breathing becomes more costal than abdominal.
Additionally, most women are mouth breathers
during pregnancy.
b. Anatomically. the diaphragm is progressively
elevated. Possibly because of expansion and
elevation of the rib cage. Uterine pressure during
the first and second trimesters does not appear to
be a factor in this phenomenon
METABOLIC AND ENDOCRINE CHANGES
1. Relaxin is a hormone secreted by the corpus
luteum. the endocrine body located in the ovary
at the site of the ruptured ovarian follicle.
a. Relaxin softens connective tissue during
pregnancy in preparation for labour and
delivery. when the pelvis must open to allow for
the birth of the foetus. Relaxin. However is not
specific to the pelvis. Other joints can also be
affected.
b. Relaxin peaks in early and late pregnancy.
Women with chronic joint instability may notice
an increase in symptoms during these times.
c. Relaxin has also been speculated to increased in the
non pregnant
women after ovulation and throughout the menstrual
period. This may cause softening of the joints and
pain in affected women.
2. Other major hormones effecting a woman during
pregnancy include estrogen, progesterone. human
placental lactogen, and
3. Edema is present in the hands. feet. face and eyelids.
This is due in part to sodium and water retention.
Additionally. hormones circulating by the placenta.
ovaries, and adrenal cortex cause increased capillary
permeability, which contributes to the edema many
pregnant women experience.
MUSCULOSKELETAL SYSTEM

Abdominal muscles are stretched to the point of
their elastic limit by the end of pregnancy.
Hormonal influence on the ligaments is profound
producing systemic decrease in ligamentous
tensile strength and an increase in mobility of
structures supported by ligaments and may
predispose the patient to joint injury especially in
the weight-bearing joints of the back, pelvis and
lower extremities. The pelvic floor muscles must
withstand the weight of the uterus, the floor
drops as much as 2.5 cm.
Postural changes:
During pregnancy, postural changes occur to
accommodate for abdominal growth.
a. These changes include forward head, rounded
shoulders, increased lumbar lordosis, hyperextended
knees, and pronated feet.
b. The center of gravity changes, resulting in changes in
balance.
c. Muscular changes are also typical. often noted
alterations include shortened hip flexors, lower back
musculature, and pectorals. Abdominal muscles,
neck, and upper back muscle groups elongate. This
may promote stretch weakness or adaptive
shortening.
Postural changes in pregnancy
Bones and joints:
There is tendency to decalcification of bones,
sublaxation of joints due to softening of ligaments
by relaxin hormone. It is more marked in
sacroiliac joint and symphysis pubis, leading to
waddling gait.
CUTANEOUS SYSTEM
Cutaneous system
Due to overstretching of the skin, the elastic
fiber may rupture together with small blood
vessels and so red streaks appear; known as
striae gravida rum. They are usually more
marked below the umbilicus, on the breasts and
may appear on the buttocks and thighs. In some
women they are not marked or even don't
appear during pregnancy. After labour, the red
striae become pale silvery white due to fibrosis
and are known as (striae albicantes).
Linea nigra
Pigmentation: It is due to suprarenal changes, it
usually begins to appear after
the 4th month. The pigmentation may appear
anywhere but the commonest sites
are:
1. Linea nigra: which is a line of pigmentation
between the umbilicus and the
symphysis pubis.
2. Increased pigmentation of the nipple as primary
areola and appearance of the
secondary areola.
Stria gravidarum
3. Cloasma gravidarum or mask face of pregnancy
which is butterfly
pigmentation of the forehead, nose, upper lip and
the adjoining parts of the
checks. This pigmentation may persist but the
cloasma gravidarum usually
disappears.
Falling of hairs and brittleness of nails may occur
during pregnancy.
Butterfly pigmentation
MATERNAL WEIGHT GAIN
There are no reliable data available for weight gain in
the first 12 weeks of
pregnancy. But in normal pregnancy the average gain
0.3 Kg/week up to 18 is
weeks, 0.45 Kg/week from 18-28 weeks and a slight
reduction with a rate of 0.360.41 Kg/week until term.
Failure to gain weight and sometimes slight weight loss
may occur in the last 2
weeks. The average weight gain for primigravidae for
the inhal pregnancy is 12.5
Kg. and is probably about 0.9 Kg. less for
multigravidae. Acute excessive weight
gain is commonly associated with abnormal fluid
retention.
Weight gain is produced by:
Fetus 3.63-3.88 Kg
Placenta 0.48-0.72 Kg
Amniotic fluid 0.72-0.97 Kg
Uterus and breasts 2.42-2.66 Kg
Blood and fluid 1.94-3.99 Kg
Muscle and fat 0.48-2.91 kg
total= 9.70-14.55Kg
NERVOUS SYSTEM
Functional changes may appear especially in
neurotic women as :
-sleepy, depressed
-while others become irritable, excited and suffer
from insomnia.
-The nausea and vomiting may have a neurotic
element.
-Change of appetite such as refusal of some types
food. of
-Neuralgias