Adaptation of the body during pregnancy

By

Dr. Ahmed

Adaptations to pregnancy

These adaptations are attributed to;

The hormones of pregnancy

Mechanical pressures arising from the enlarging uterus

Other issues.

These adaptations; Protect the woman`s normal physiologic

functioning

Meet the metabolic demands pregnancy imposes on her body

Provide a nurturing environment for fetal development and growth.

The pregnant woman, her partner and

family must all adjust to the reality of

pregnancy and anticipated new roles as

mother, father, grandparent or sibling.

Body systems affected by pregnancy

Other body systemsReproductive system

oCardiovascular

oRespiratory

oUrinary

oGastrointestinal

oMusculoskeletal

oIntegumentary

oMetabolic changes

oEndocrine

oImmunological

oUterus

oCervix

oOvaries and fallopian

Tubes

ovagina

oVulva

oBreast

Uterus:The phenomenal uterine growth in the first trimester

is simulated by high levels of estrogen and progesterone.

Size: increase to 20 times of its non-pregnant size due to increased vasculariy, hyperplasia and hypertrophy.

Weight: increase from 50 grams – 1000 grams.

Volume: increases from less than 10 ml to 5000 ml.

Contraction: Braxton Hicks sign ( irregular, painless intermittent uterine contraction).

Shape: changes from that of an inverted pear to that of soft globular or spherical. Later it become ovoid and rises out of the pelvis into the abdominal cavity.

Uterus: continue-

Endometrium : consists of 3 layers:

1. Decidua basalis

2. Decidua capsularis

3. Decidua vera

Cervix: 1. Goodell’s sign; softening of cervix

2. Operculum ( mucus plug)

Ovaries and fallopian tubes:

Involution due to suppression of FSH

Vagina:

Chadwick’s sign; bluish color, cervix,

vagina

Hypertrophy and hyperplasia

Leukorrhea , acid pH 3.5 to 6 (a

whitish or yellowish discharge of

mucus from the vagina).

Vulva:

Increased vascularity

Fat deposition causes labia majora to

close and partially cover introitus.

Breasts:

3-4 weeks: prickling, tingling sensation

6 weeks: developing ducts and glands

8 weeks: bluish surface veins are visible

8-12 weeks: Montgomery’s glands become

more prominent, primary areola become

darker.

16-18 weeks: colostrum expresses.

Secondary areola appears.

Adaptation of other body systems

Cardiovascular system:

Slight enlargement of myocardium

Shift in chest contents:

- Heart is displaced upwards and to the left

Heart rate increases by 10 to 15 b/m

Blood volume increases 40-50% physiological anemia

Hemoglobin and hematocrit decrease in relation to increased plasma volume

Cardiac output increases by 30% during the 1st and 2nd trimesters.

Respiratory system:

The upper respiratory tract becomes more vascular in response to estrogen that can result in nasal stuffiness, epistaxis, voice changes, impaired hearing and a sensation of fullness in the ears..

Enlarged uterus prevent the lungs from expanding shortness of breath.

Basal metabolic rate increases and oxygen requirement increases by 30 to 40 ml\min.

Urinary system:

Frequency of micturition due to pressure

of the growing uterus.

Decreased bladder capacity and bladder

tone.

Renal functions changes:

Changes occur to accommodate an increased

workload while maintaining stable electrolyte

balance.

Increased glomerular filtration rate.

Glucosuria may occur.

Gastrointestinal system:

Gums become hyperemic and have a tendency to bleed.

Ptyalism is seen in some women.

Smooth muscle relaxation occurs related to increased progesterone production; this can cause:

Decreased peristalsis and constipation.

Heartburn, slowed gastric emptying and esophageal regurgitation.

Hemorrhoid from the pressure of the gravid uterus.

Appetite usually increases, after a temporary decrease due to nausea and vomiting.

Musculoskeletal system:

Alteration in posture can result in lordosis

( waddling gait due to increased level of

progesterone and relaxing hormone).

Diastasis recti is associated with enlarged

uterus in some women.

Relaxation and increased mobility of

joints occur because of the relaxing

hormone.

A, Normal position in no pregnant woman. B,

Diastasis recti abdominis in pregnant woman.

Integumentary system (cutaneous changes)

Chloasma is the brownish “ mask of

pregnancy”.

Nipples, areolae, axilae, vulva and

perineum all darken.

Striae graviderium ( stretch marks)

appear on the breasts and abdomen.

Striae gravidarum,

Metabolic changes:

Increase metabolic rate.

Increase the demands for carbohydrate,

protein and minerals.

Weight gain of 9-11 kg.

Water requirement is increased to supply

fetus, placenta and amniotic fluid.

Endocrine system: FSH and LH production is suppressed.

Thyroid gland enlarges, resulting in increased iodine metabolism.

Pancreas: Insulin production is increased throughout pregnancy to compensate for placental hormone insulin antagonism.

Ovaries produce: Estrogen

Progesterone

Relaxing hormone.

- Relaxing can regulate the mother’s cardiovascular and renal systems to help them adapt to the increase in demand for oxygen and nutrients for the foetus.

Immunological system:

Resistance to infection is decreased.

Maternal IgG levels are decreased.

Maternal IgM levels remain unchanged.

Pregnancy signs and symptoms

Presumptive evidence: woman

reports

Signs:Amenorrhea.

Breast changes.

Chloasma and lina nigra.

Chadwick’s sign; bluish color of the

cervix during pregnancy.

Abdominal enlargement and striae.

1.Presumptive evidence: continued-Symptoms:Nausea and vomiting

Urinary frequency

Weight gain

Constipation

Fatigue

Quickening

Breast tenderness, tingling, and heaviness.

2.Probable evidence : Noted by examiner

Goodell’s sign - softening of cervix

Chadwick’s sign - bluish color, cervix, vagina

Hegar’s sign - softening of lower uterine segment

◦ Enlarged abdomen

◦ Pigmentation changes

◦ Stretch marks

Ballottement- A method of diagnosing pregnancy, in which the uterus is pushed with a finger to feel whether a fetus moves away and returns again.

Positive pregnancy test

Palpation of fetal outline

Figure 7–4 Hegar’s sign, a softening of the isthmus of the uterus, can be determined by the examiner during a vaginal examination.

3. Positive ; Noted by examiner - only

caused by pregnancy;

Hearing of fetal heart rate.

Fetal movement palpable by the

examiner

Fetal parts felt by examiners.

Visualization of the fetus by

ultrasound.

Positive evidence:

.