Physiological changes in pregnancy Flashcards
What happens to the uterus by the 12th week of pregnancy?
The uterus rises out of the pelvic cavity and becomes upright.
By which week is the uterus midway between the umbilicus and symphysis pubis?
By the 16th week.
When is the uterus just below the umbilicus?
By the 20th week.
Where is the uterus located by the 30th week?
It is midway between the umbilicus and xiphisternum.
What happens after 38 weeks of pregnancy regarding the uterus?
- Lightening occurs
- The fetus sinks down
- Fundus can be palpated below the xiphisternum.
How does lightening affect maternal breathing?
Maternal breathing usually improves after lightening.
How does the cervix change during pregnancy?
The cervix remains tightly closed during pregnancy.
What happens to the mucous in the cervix during pregnancy?
The mucous becomes thicker and more viscous.
How does the vaginal wall change during pregnancy?
The vaginal wall becomes thicker and more vascular.
How does blood supply to the venous plexus in the vagina change?
The blood supply increases.
How do the labia minora change during pregnancy?
The labia minora become more pigmented.
What changes occur in the vulva during pregnancy?
Superficial varicosities may appear, and the vulva skin becomes edematous.
What causes pain at the vulva and thigh during pregnancy?
Pudendal nerve compression.
What causes pain in the right and left iliac fossa during pregnancy?
Stretching of the round ligament.
How do pregnancy hormones affect the vascular system?
Pregnancy hormones cause vasodilation of the smooth muscle in the vascular system.
How does blood pressure change during pregnancy?
BP initially reduces until about 22–24 weeks and then rises to pre-pregnancy levels at term.
What happens to systemic vascular resistance during pregnancy?
Systemic vascular resistance falls, leading to an increase in cardiac output.
How does the ventricular muscle mass change during pregnancy?
It increases to accommodate the higher cardiac output.
When does cardiac output reach its maximum during pregnancy?
Around 28 weeks until term.
What happens to the inferior vena cava during pregnancy?
The gravid uterus exerts pressure on the IVC, which can lead to supine hypotension syndrome
How does heart rate change during pregnancy?
Heart rate increases, peaking around 32 weeks.
What happens in the supine position during labor?
Cardiac output increases by up to 25% due to uterine contractions, and stroke volume increases by up to 35%.
What is the effect of the recumbent position during labor?
It results in better hemodynamic parameters, with minimal increase in cardiac output, stroke volume, and heart rate.
What position helps avoid supine hypotensive syndrome?
Left lateral recumbent position.
Why does oxygen demand increase during pregnancy?
Due to increased oxygen consumption and metabolic demand.
How does the capillary system change in pregnancy?
Capillaries dilate, causing engorgement throughout the respiratory system, including the nasopharynx, larynx, trachea, and bronchi.
What happens to minute ventilation during pregnancy?
Minute ventilation increases by 40%.
Does the respiratory rate change during pregnancy?
No, respiratory rate does not change.
What happens to tidal volume during pregnancy?
Tidal volume increases.
How is the forced expiratory volume (FEV1) affected by pregnancy?
There is no change in FEV1.
What happens to the subcostal angle during pregnancy?
The subcostal angle increases.
How does chest circumference change during pregnancy?
Chest circumference increases.
What happens to PO2 and PCO2 during pregnancy?
PO2 increases, while PCO2 decreases.
How does total lung capacity change in pregnancy?
Total lung capacity decreases by 15%.
What happens to plasma volume and red cell mass during pregnancy?
Plasma volume increases more than red cell mass, leading to hemodilution.
How does hemoglobin concentration change during pregnancy?
Hemoglobin concentration falls.
What happens to platelet count during pregnancy?
Platelet count falls progressively but stays within normal limits.
How does the white cell count change during pregnancy?
White cell count increases, mainly due to polymorphonuclear cells.
What is the state of the coagulation system during pregnancy?
Pregnancy is a hypercoagulable state.
What contributes to thrombosis risk during pregnancy?
Venous stasis and pressure from the gravid uterus.
What causes relaxation of smooth muscle in the gastrointestinal tract during pregnancy?
The high levels of progesterone.
What is the effect of progesterone on the lower esophageal sphincter?
It reduces the tone, increasing the risk of gastroesophageal reflux.
How does the transit time in the gastrointestinal tract change during pregnancy?
Transit time increases, and peristalsis is reduced.
What happens to the small bowel during pregnancy?
Small bowel motility is reduced, which enhances iron absorption.
What happens to the large bowel during pregnancy?
The transit time increases, leading to more water absorption and constipation.
How does the gallbladder change during pregnancy?
Gallbladder emptying is delayed, which can predispose to gallstone formation.
How does the liver function change during pregnancy?
- Albumin and globulin levels decrease
- Liver enzyme and serum bilirubin levels remain unchanged
- Alkaline phosphatase levels increase.
What happens to the ureters during pregnancy?
Ureters dilate due to progesterone and pressure from the gravid uterus.
How does kidney function change during pregnancy?
- Renal plasma flow (RPF) and glomerular filtration rate (GFR) increase,
- Urea, creatinine, and uric acid levels decrease.
What is the risk of urinary tract infections during pregnancy?
Pregnancy increases the risk of urinary tract infections, with up to 4–7% of women developing asymptomatic bacteriuria.
How does the thyroid change during pregnancy?
The thyroid increases hormone production due to elevated hCG levels, affecting thyroid metabolism.
How does the parathyroid change during pregnancy?
Parathyroid glands enlarge, and calcium absorption increases to support fetal development.
How does the insulin resistance change during pregnancy?
Insulin resistance increases due to placental hormones, leading to potential gestational diabetes.
How do the spine and pelvis change during pregnancy?
The spine’s curvature changes, often causing lower back pain, and pelvic instability may occur due to ligament relaxation.
What causes pelvic discomfort during pregnancy?
Relaxation of ligaments and joints due to pregnancy hormones, especially relaxin.
How does pigmentation change during pregnancy?
Increased hyperpigmentation
- chloasma (darkened facial areas)
- linea nigra (dark line on the abdomen).
What happens to hair growth during pregnancy?
Increased hair growth, and mild hirsutism (excess hair growth) may occur.
What are common skin changes during pregnancy?
Stretch marks (striae gravidarum) may appear, especially on the abdomen, breasts, and thighs.
