Nursing Student
New Grad

03.01 Physiological Changes

This lesson is part of the Nursing Student Academy. Start a trial to view the entire video.


  1. Physiological changes are changes that affect how the body functions
  2. Normal changes
  3. Many of these changes are due to an expanding uterus (and therefore pelvis), an increase in oxygen consumption and circulating blood volume, and fluctuations in various hormones

Nursing Points


  1. Pregnant women should be seen regularly to identify complications early.
  2. Scheduled of prenatal visits:
    1. Q4 weeks from 8-32 weeks
    2. Q2 weeks from 32-36 weeks
    3. Q1 weeks from 36-40 weeks


  1. Hormones
    1. Estrogen, Progesterone, HCG, Aldosterone
  2. Cardiovascular
    1. More blood volume
    2. Murmurs can be normal
    3. Edema/fluid retention
    4. Increased pulse 10-15 BPM
    5. Blood pressure decreased in second Trimester
    6. Increased preload and cardiac output
  3. Gastrointestinal
    1. GI track slows down→ progesterone
      1. Constipation
      2. Nausea/vomiting
      3. Bloated feeling
  4. Renal
    1. Frequent urination
      1. Uterine weight, fetal size
    2. Increased risk of UTI
  5. Respiratory
    1. Increased oxygen consumption
    2. Increased ventilation
  6. Musculoskeletal
    1. Gait changes
      1. Relaxin hormone
      2. Changes to pelvic girdle
  7. Hematologic
    1. Increased coagulopathies→ increased risk  for DVT

Therapeutic Management

  1. Not much therapeutic management
  2. Treat any discomfort that changes are causing
    1. Band to lift growing uterus and relieve back discomfort
    2. Medications for GI discomfort
    3. Diet to manage constipation

Nursing Concepts

  1. Reproduction
  2. Human Development

Patient Education

  1. Normal changes to expect
  2. Ways to improve symptoms
    1. Eat crackers before rising from bed
    2. Don’t let stomach get empty → increases nausea
    3. Importance of maintaining correct posture→ prevent musculoskeletal discomfort and back pain
  3. When to be concerned
    1. Frequent vomiting causing weight loss
    2. Signs of blood clots, DVTs
    3. UTI symptoms

Reference Links

Create Your Account

Get unlimited access to lessons and study tools

Video Transcript

In this lesson I will explain the physiological changes that occur in pregnancy in a more understandable way

Physiological changes are those changes that occur to the bodies functions. So not the physical looks but how it functions. The changes are normal and caused by mostly hormones (Estrogen, progesterone, HCG, Aldosterone), growing and expanding uterus, and an increase in blood volume. These physiological changes affect the heart, respiratory, musculoskeletal, gastrointestinal, and renal system.

A head to toe assessment should be done to look for any changes. The patient should be Interviewed to identify changes she has noticed and if she has any concerns. Reassuring the patient that the changes are normal can be comforting for the patient.

It is important to know the main cause of these changes. Hormones are a large cause and the ones really involved are estrogen, progesterone, HCG, aldosterone. Estrogen is responsible to an increase in vascularity and nasal congestion. Progesterone is responsible for keeping the body pregnant. So it slows everything down like the gastrointestinal tract. This cause constipation and bloating. It also keeps the uterus from contracting to maintain that pregnancy. HCG is increasing and doubling as the pregnancy gets further along. This is going to cause the nausea and vomiting for the gastrointestinal tract. Aldosterone increases the plasma volume. This will be more work for the heart but helpful post delivery when there is a lot of bleeding. The respiratory system is changes because of an increase in oxygen consumption. Also because of the hormone estrogen there is an increase in nasal congestion and stuffiness. Nosebleeds are common because of this. The gastrointestinal system is going to slow down. This is mainly because of which hormone? Yes, progesterone. So this is going to cause constipation, nausea/vomiting, and bloating. The renal system changes in ways that there is more frequent urination. This is because not just the weight of the uterus/fetus and it grows but also because of rising hormone levels. UTI risk is greater because of the weight of the uterus can cause blockade so not all the unit is able to exit. You can see in this picture how there is a small area to grow a baby. This causes the respiratory system to be crunched and the GI system to be bothered easily. Also with aldosterone increasing the plasma levels and the weight of the uterus hypotension is a big side effect. So let’s switch and talk about this cardiovascular system in more detail.

The cardiovascular system is changing as there is increasing blood volume. This picture gives a better visual. You can see blood volume increases 30-50%. In the third trimester the plasma amounts really increase and this causes anemia. The plasma amounts increase a lot where the red blood cells increase only a small amount. This causes the hematocrit to go down. Because of the increasing volume, murmurs might be heard and are normal. Edema will also occur as well as an increase in pulse by 10-15 BPM. Blood pressure also is reduced in the second trimester. hormonal changes cause the blood vessels to dilate so the blood pressure lowers. The blood pressure is usually at its lowest sometime in the middle of the second trimester. These changes can cause a lightheaded feeling and of course passing out can cause some uneasiness to the patient so just an an example of one of the changes that could concern the patient. The musculoskeletal system changes because of hormones and the uterus. So a hormone called relaxin causes the system to relax. It allows for the system to open up and allow room for the growing fetus. Also we have posture changes. We see lumbar lordosis because of the shift in the center of balance and the growing uterus. The hematologic system sees changes in coagulopathies. These increase, which are needed to clot off and stop too much bleeding post delivery but also increase the risk for DVTs.

There is not much therapeutic management. We want to treat any discomfort that changes are causing if possible. Some of these changes are a band to lift the growing uterus and relieve back discomfort, medications for GI discomfort and diet to manage constipation can also help such as ondansetron (zofran).

It is important that they know these are normal changes and what to expect. We want to give them ways to improve symptoms. Nausea will be a big complaint so ways to improve symptoms are to eat crackers before rising from bed, don’t let stomach get empty. It is also Importance of maintaining correct posture to prevent musculoskeletal discomfort and back pain. We want to tell them when to be concerned and symptoms to call about. These would be frequent vomiting causing weight loss, signs of blood clots, DVTs and UTI symptoms.

Reproduction is a concept because the pregnancy is causing the physiological symptoms to happen. Hormonal regulation is the last concept because hormones are a big cause for all the changes that are occuring.
Let’s review some of the main key points to remember. Many of these changes are due to hormones which are estrogen, progesterone, HCG, and aldosterone. The expanding uterus (and therefore pelvis) will cause musculoskeletal discomforts. There is an increase in oxygen consumption which will affect the respiratory system. We have that increasing circulatory blood volume which is putting more work on the heart. Last it is important to remember and remind the patient that these are normal pregnancy changes.

Make sure you check out the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing.

  • Question 1 of 10

A pregnant client calls the OB office to report recurring nosebleeds. What is the best response by the nurse?

  • Question 2 of 10

A nurse is caring for a pregnant client who is at 28 weeks’ gestation. Which of the following changes in cardiac output would the nurse expect to see in a client of this gestation?

  • Question 3 of 10

Which best describes how pregnancy affects thyroid function?

  • Question 4 of 10

Which symptom reported by a pregnant client would be most concerning to the nurse?

  • Question 5 of 10

A client who is 16 weeks pregnant is at the healthcare provider’s office for a routine prenatal exam. The nurse is educating the client about pregnancy-related body changes that may occur in the next several months. Which best describes a condition that affects the musculoskeletal system occurring during pregnancy?

  • Question 6 of 10

A client who is 37 weeks pregnant has collapsed in the hallway of the hospital. A nurse responds and discovers that the client does not have a heart rate. Which intervention must be modified because of this client’s pregnancy in order to respond to this situation?

  • Question 7 of 10

The nurse is working in a OB clinic, seeing a client who is 9 weeks pregnant. Which of the following statements by the client is the LEAST concerning?

  • Question 8 of 10

A nurse is providing discharge teaching to a 32-week pregnant client after her OB appointment. The client has had edema in her lower legs and ankles. What advice should be included in teaching?

  • Question 9 of 10

A 17-year-old pregnant client is receiving prenatal care at the health clinic. The client states the anticipation of her body changing has caused her to have an emotional crisis. Which of the following interventions would be most appropriate for this client?

  • Question 10 of 10

A nurse is caring for a client at her 10-week OB appointment. The client expresses concern and asks why she is already going to the bathroom so frequently when she is only 10 weeks pregnant. What is the most appropriate response by the nurse?

Module 0 – OB Course Introduction

Customize Your Study

Start a trial to create your first custom study plan now.

Start Trial