Common Third Trimester Conditions (Including Appetite Changes)

Updated: April 25, 2022
Based on content from the book 'Eat Right for Your Baby', this article covers all you need to know about common third trimester pregnancy conditions including: loss of and increased appetite, constipation, edema, shortness of breath, high blood pressure and UTIs.
Third Trimester
Table of contents

The third trimester is dedicated to intensive fetal growth. Your fetus will gainfully half its weight during this period. In the final months, there will be further essential lung and brain development.

The food you eat during the final three months is directly utilized in increasing your baby's birth weight. The quality of the food you eat continues to be of primary importance. Check out Eat Right for Your Baby by Dr. Peter J. D'Adamo (Author), Catherine Whitney (Author) to learn more about healthy eating habits during pregnancy.

As you approach the birth of your baby, typically after some 40 weeks, it's normal to feel equal measures of excitement and apprehension. If this is your first pregnancy, you're entering the great unknown. You may find your thoughts filled with worries about whether your baby is all right and dread about what you'll experience during labor.

If you've participated in childbirth classes and have a strong partnership with your doctor or midwife, some of that anxiety will be alleviated. And if you've adhered to your blood type plan, you can have some degree of confidence that you've done the best you can to assure a healthy baby.

The key now, as you prepare for labor, is to be as physically and mentally prepared as possible. Continue to gain about one pound per week during the seventh and eighth months. Your weight may stabilize, and you may even drop a pound or two during the ninth month.

Common Third Trimester Conditions

Basic Third Trimester Conditions

Lack of Appetite

Many pregnant women experience a decreased appetite, and many of their cravings disappear in the third trimester. The main reason is the pressure of the growing fetus on your abdomen. There's simply less room for food. The best way to combat this is by eating small meals every few hours. Frequent meals with small servings give your body a chance to digest small amounts of food and help empty the stomach quickly.

While staying hydrated is a must, avoid filling up on liquids unless it is a healthy protein shake or meal substitute. Since you have less room in your stomach right now, don’t drink your fluids with your meal. Fluids can quickly fill up our bellies, leaving less room for the nutritious food our baby needs.

Loss of appetite may also be a result of frequent heartburn or indigestion. You may also be experiencing food aversions or suffering from occasional morning sickness still.


Constipation, which afflicts many women in early pregnancy, often reappears in the final months of pregnancy. Frequent constipation can lead to another uncomfortable condition, hemorrhoids.

A diet rich in fiber and staying hydrated can often help with constipation. However, some women experience the flip side and have diarrhea. To learn more about pregnancy and bowel movements, check out Pooping and Pregnancy: A Step-by-Step Guide.


Sluggish metabolism, often triggered by eating the wrong foods for your blood type, leads to an accumulation of extracellular water, which, in turn, causes edema. Edema in pregnancy is caused by hormone-induced sodium retention. Mild swelling, especially in your legs and feet, is typical and alone should not be considered alarming.

The American Pregnancy Association says that swelling may also be caused by:

  • Heat
  • Standing for long periods
  • Busy or active days
  • Not enough potassium intake
  • Too much caffeine intake
  • Too much sodium intake

Contact your healthcare provider immediately if you experience edema combined with lightheadedness or dizziness, vision problems, high blood pressure is only in one leg or foot or is warm to the touch.

High Blood Pressure

If your edema is more serious, it could be a sign of preeclampsia. Preeclampsia is a severe medical condition associated with elevated blood pressure. Even women who are not generally at risk for high blood pressure sometimes develop pregnancy-induced hypertension. High blood pressure can restrict blood flow to the placenta and rob your fetus of oxygen and vital nutrients.

If you have hypertension, you'll need to get more rest and even stay off your feet.

According to the American College of Obstetricians and Gynecologists (ACOG), risk factors for preeclampsia are:

  • Obesity (Body Mass Index of 30 or higher)
  • Carrying multiples
  • Preeclampsia during a previous pregnancy
  • Autoimmune diseases
  • First pregnancy
  • Kidney disease
  • Being older than 35
  • A family history of preeclampsia

Shortness of Breath/Fatigue

By the third trimester, you'll be carrying a heavy and awkward load. And even in a completely healthy pregnancy, the pressure of the expanding uterus on your respiratory system can cause shortness of breath even with mild exertion.

Fatigue can also be caused by sleeplessness. Many women have trouble sleeping in the final months because they can't get comfortable. Try using a pregnancy support pillow or sleeping in a reclined chair.

Indigestion and Heartburn

You may find that the pressure from your growing fetus constricts your digestive tract, forcing stomach contents back up through the esophagus. You can minimize acid reflux or heartburn by eating small, regular meals, chewing food thoroughly, and eating slowly. Also, don’t lie down for at least an hour after eating.

If indigestion and heartburn become a frequent problem, some supplements may help relieve your symptoms. However, you should always speak with your doctor before taking any medications or supplements.

Urinary Tract Infections

UTIs are common during pregnancy. However, in the third trimester, they are more serious because of the potential for developing a kidney infection. Kidney infections can provoke preterm labor. If you suspect you have a UTI, contact your doctor as it can only be treated with antibiotics.

Signs of a UTI may include:

  • Frequent urination or constantly feeling like you need to go
  • Pain or burning sensation when you pee
  • Blood in your urine
  • Cloudy or dark urine
  • Pelvic pain

Signs of a Kidney infection include all of the above plus:

  • Side or back pain
  • High fever
  • Chills or shaking
  • Nausea and vomiting

Find out more about urinary and vaginal problems that can occur during your pregnancy from Dr. Chloe Zera of Brigham and Women's Hospital in Boston.

Exercise Guidelines

Third Trimester Exercise

Exercising while pregnant has multiple benefits to both you and the baby! It can prevent potentially serious complications, such as high blood pressure that can lead to preeclampsia; it can help decrease stress and help you sleep better. In addition, it will allow you to maintain a healthy weight gain. Exercise during pregnancy may also prevent some of the aches and pains associated with carrying extra weight, such as back pain and stiff muscles.

However, pregnancy is a different experience for each individual, so it is best to approach your exercise program with care and attention to both form and function. You should always discuss your exercise plans with your health professional, even if you were working out pre-pregnancy. In most cases, it is ok and recommended to carry on with light workouts such as walking and yoga throughout your third trimester of pregnancy.

It is common for women in the final months to feel short of breath, especially when exercising. Awkwardness, leg cramps, and pelvic aching can all hinder your ability to exercise as fully as you once did. Be mindful of your body’s abilities and rest when needed. When doing floor exercises, rise gradually from the floor to avoid dizziness and avoid laying flat on your back during the third trimester.

More: Prenatal Strengthening and Toning Exercises

How to Be a Supportive Partner During the Third Trimester

As your partner's pregnancy progresses, be aware of your own stress triggers. A recent study showed that men gained an average of three to four pounds during their partners' pregnancies. In addition, first-time fathers tended to eat and drink too much in response to stress. Lend your partner an ear so they can discuss any concerns or worries they may be having, which may increase as your baby’s due date looms near.

Pick up some extra chores around the house without being asked and cook some delicious meals that cater to her food cravings and ensure you are both eating well.

Be a supportive and active teammate and offer to go to doctor visits with her and learn important health information about pregnancy and newborns together.

Pre-Birth Checklist: How to Prepare for Birth and a New Baby

Perineal Massage

Third Trimester Massage

Your body is making lots of new hormones that enhance the relaxation and elasticity of your muscles. This elasticity allows your abdomen and pelvis to accommodate the rapidly growing fetus. You can use this to your benefit by beginning to stretch the vaginal opening to ease the delivery of your infant's head and minimize the need for an episiotomy.

Recline comfortably, either on your bed or the floor. Place a small amount of warm almond or olive oil on your thumb. Insert your thumb into the vaginal tract, and gradually apply light pressure downward toward your feet. Do this for a count of 10, then allow another count of 10 for relaxation. Repeat five to six times. Practice this stretching routine daily in the third trimester and invite your partner to participate.

Yoga and Meditation

Participating in yoga, gentle stretching, and meditation can not only relieve some of the third-trimester aches and pains, but it can help prepare you for birth by keeping your body and heart strong. Look for yoga classes or videos geared explicitly towards pregnancy and women’s health.

Breathing Exercises

If you took Lamaze classes, continue practicing your breathing exercises. Oxygen helps calm us and keep us focused. Deep, full breaths from your abdomen can calm anxiety and relax your body. Try placing your hands on your abdomen to focus the breath there and count slowly to ten as you breathe in, hold it for a few counts, and then breath out, counting down from ten.

Breastfeeding Prep

If you plan to breastfeed or pump breastmilk and use bottles, begin doing your prep work. See if your hospital or birthing center has a lactation consultant that will meet with you after birth. Ensure you have the needed supplies such as a nursing pillow, breast pads, a pump, storage containers, nipple cream, and breast shields.

Most insurance companies will fully or partially cover a breast pump, so contact your insurance carrier to discuss coverage options. If you plan to breastfeed, you should plan on eating a similar diet to your pregnancy one. Your breast milk provides your baby with important nutrients, so stock up on fresh fruits and veggies, whole grains, calcium, and vitamin D-rich foods.

Are you in your first or second trimester? Check out First Trimester Basics and Second Trimester Basics!