Maternal and fetal responses to labor

Physiologic and psychologic effects of labor on the mother

Physiologic effects: Cardiovascular system:

S ٍٍٍٍtrenuous work on the heart causing increased cardiac output, blood pressure and pulse rate.

During a contraction blood flow to the uterus decreases which leads to increase blood amount in the general circulation and thus increase in the peripheral resistance and resulting in increase in blood pressure (systole and diastole).

Blood loss (300 – 500 ml) aids in reducing blood volume.

Blood pressure: with the increased cardiac output during contractions, systolic blood pressure rises an average of 15mm Hg with each contraction.

When lying in supine position and pushes, her BP can drop leading to hypotension (upright or side lying position during the second stage can help avoid such a problem

Hemopoietic system:

Leukocytosis or sharp increase in WBCs possibly due to stress and heavy exertion (reaching 25,000/mm³ to 30,000/mm³ cells.

Respiratory system: With increased cardiovascular output, the

body responds with increased respiratory rate to provide oxygen leading to hyperventilation

Consumption of Oxygen is up to 100% during the second stage (similar to running)

Temperature regulation:

Increased muscular activity during labour leads to increased body temperature (1 degree)

Diaphoresis and evaporation helps the body to lose temperature

Fluid balance: Factors affecting fluid balance:

Increased rate of respiration Diaphoresis (insensible water loss) Withholding fluid during labor

All may necessitate IV fluid replacement

Urinary system: With decreased fluid intake, kidneys begin

concentration urine to preserve fluid and electrolytes

Increased specific gravity (1.020 -1.030) Protein in urine due to protein breakdown

(muscle exertion) Loss of sense of bladder filling (tone)

which leads to overfilling. (During labor a woman must void every 2 hours)

Musculoskeletal system: Relaxin (released from ovaries) during

pregnancy resulted in softening cartilage between bones (symphysis pubis and sacro coccyx joints) lead to backache and pain at pubis during walking

Gastrointestinal system: Fairly inactive during labor Prolonged time of stomach emptying

explain why food intake is restricted during labor

Loose bowel movements

Neurologic and sensory responses: Responses related to pain (increased

pulse and respiratory rate) Pain due to contraction and perineal

stretching

Psychological responses to labor

Fatigue: Generally tired at the end of pregnancy Lack of sleep

Fear: Fear of labor (remind mother of the

process taught earlier).

Cultural influences

Fetal responses to labor: Neurologic system: uterine contractions

exert pressure on fetal head results in increased intracranial pressure.

Decreased fetal heart rate by 5 bpm during a contraction. This decrease appears on the fetal monitor as an early deceleration pattern (normal during labor)

Cardiovascular system: With contractions the uterus is arteries are

sharply constricted and cotyledons filling halts leading to reduced oxygen and nutrients

Integumentary system: Minimal petachiae or echymotic areas on

the fetus, caput succedaneum

Musculoskeletal system: Contractions encourage full flexion attitude

Respiratory system: Labor assists in the maturation of

surfactant production by alveoli Pushing aids in clearing the lung fluid

Danger signs of labor

Feat signs: High or low fetal heart rate

FHR: 120 – 160bpm More than 16o or less than 120 means possible

fetal distress

Meconium staining: a green color in the amniotic fluid: episode of loss of sphincter control allowing meconium to pass into meconium

Fetal Hypxia

Normal in breech presentation

Hyperactivity: normally the fetus is quiet during labor and hyperactivity indicates hypoxia is occurring (Need for oxygen)

Fetal acidosis: Blood pH below 7.2 is a sign of acidosis

Maternal Danger signs: 1. Rising or falling blood pressure

Increase of systole greater than 140 mmHg (more than 30 mmHg) or 90 of diastole (more than 15 mmHg) are indicative of pregnancy induced hypertension.

Falling Bp is indicative of intrauterine hemorrhage

2. Abnormal pulse: Normal pulse increases slightly during the

second stage of labor due to exertion Increased to more than 100 bpm is

indicative of hemorrhage

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3. Inadequate or prolonged contractions: Normally contractions increase in

frequency, duration, severity. If contractions become less intense, shorter in duration or less frequent it indicates uterine exhaustion or inertia ( may need Cesarean birth)

4. Pathologic retraction ring: A sign of extreme uterine stress and

impending uterine rupture Observe the abdominal contour

periodically

5. Abnormal lower abdominal contour:

A full bladder during labor is manifested as a round bulge on the lower anterior abdomen. This isa danger sign for tow reasons: 1. Bladder injury by fetal head pressure 2. Pressure of full bladder inhibits fetal

head descent

Increasing apprehension: May be a sign of oxygen deprivation or

internal hemorrhage