Maternal Cardiovascular Changes and Signs of Labor
Cardiovascular Changes in the Mother
The cardiovascular response is influenced by multiple factors: individual, specific to each woman, and predictable, among which include posture, mode of delivery, and anesthesia or analgesia used.
- Minute volume: There is a further increase in cardiac output. Each uterine contraction causes changes in cardiac output as a function of the body position that the woman takes. During the second stage, the minute volume increases up to 50% and during delivery up to 80%.
- Heart rate: During the period of expansion, the heart rate decreases to 80 beats per minute. During the second stage of labor, the heart rate increases to 100 beats per minute. The heart rate normalizes 10 minutes after delivery.
- Stroke volume: Increases by 60%-80% and decreases at the end of the second stage of labor.
- Blood pressure: A modest increase is produced during contractions. In the second stage of labor, it increases to 20mm Hg systolic and 15mm Hg diastolic. It returns to normal after delivery.
- Volemia: No significant changes during labor. In the first 72 hours, it decreases by 25%. At the end of the puerperium, it is normal.
- Venous pressure: It remains constant throughout gestation in the portion of the body located above the uterus but is increased in the portion located below the pelvis.
Leopold Maneuvers
- Used to delimit the fundus and know which fetal pole occupies it.
- Feeling on either side of the uterus allows one to know where the back and small parts are.
- Try to cover with one hand the fetal pole in front of the pelvis.
- With both hands, try to cover the presentation to complete the discovery of the third.
Approach to the Signs of Labor
- Lightening: Two weeks before labor begins, primigravidas note that the uterus falls below the abdomen. The placement of the fetus in the brim of the pelvis is called lightening. It reduces pressure from the uterus against the diaphragm, and the pregnant woman can breathe more easily. The uterus puts pressure on the bladder again and causes urinary frequency.
- False Labor: The contractions of false labor are an exaggeration of the Braxton-Hicks contractions that occur during pregnancy. They are painful, short-lived, and at irregular intervals. They are relieved by walking. The difference between false and true labor is that in false labor, the cervix does not dilate.
- Show (mucus plug): Just before real labor begins, the patient has a small amount of pink vaginal discharge. This is called the show and is the cervical canal mucus plug mixed with some blood. Labor usually begins 24 hours after the onset of the show.
- Spontaneous rupture of the membranes: Occasionally, this occurs before labor. The dangers that accompany spontaneous rupture of the membranes include infection and cord prolapse. The membranes that surround and contain the fetus and amniotic fluid act as a protective barrier against infection. When they break, this barrier disappears, and they become very susceptible to infection. Take the temperature at frequent intervals in search of fever due to infection. Vaginal examinations are done only when absolutely necessary and with the utmost hygiene.