31 Weeks Pregnant: Symptoms And Baby Development

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How Many Months Pregnant Are You At 31 Weeks?

You are in the third trimester of pregnancy at the 31st week of pregnancy and a week short of ending the seventh month. You will soon be in the eighth month.

Here, we elaborate on fetal development and the changes you may experience in the 31st week.

How Big Is Your Baby In This Week?

At 31 weeks, your baby is about the size of a coconut. Your baby measures 16.18in (41.1cm) in length and weighs about 3.31lb (1.5kg) (1).

Baby Development At 31 Weeks

Here is how the baby is developing in this week:

Body partsDevelopmental stage
Skin (2)Looks smooth and less wrinkled. Fats get deposited under the skin layer
Lungs (3)Still developing
BonesFully developed but are soft
EyesAre open, and the pupil can respond to light. Regular sleeping patterns are developed
EarsCould get startled by loud noises
BrainDeveloping faster and sending out a lot of signals
Heart (2)More than 40 million heartbeats have occurred by this time
Kidneys (4)Starts producing urine
MouthThe baby starts to suckle and swallow and can get hiccups
Senses (5)The baby can see, hear, taste, and feel the touch but cannot smell until delivery
Lanugo (6)Begins to disappear

Pregnancy Symptoms You Experience In The 31st Week

Here are a few symptoms you may experience this week:

  1. Weight gain: By the 31st week, the weight gain should be as follows (7):
Body weightNormal weightOverweight Obese
Weight gain27-39lb (12-18kg)22-35lb (10-16kg)18-30lb (8-13kg)
  1. Shortness of breath as the diaphragm is pushed upward by the growing uterus. Breathing exercises can help you get relief.
  1. Braxton Hicks contractions are irregular, less painful contractions that help the body prepare for labor. Drinking plenty of water and changing your positions can relieve the discomfort.
  1. Frequent urination due to the pressure exerted by the growing uterus on the bladder.
  1. Backaches because of the burden of carrying the extra weight of the baby.
  1. Headaches due to the hormonal fluctuations, stress, or dehydration. In some cases, a headache may be the first sign of pregnancy-induced hypertension.
  1. Diarrhea as the hormonal changes can slow down the digestion process. You could also become sensitive to certain foods, which can lead to diarrhea. In such a case, drink plenty of water and stay hydrated. Try to avoid spicy or preserved food. Go for fresh, home-made food and fruits.
  1. Clumsiness due to to the postural changes and a shift in the center of gravity of your body.
  1. Insomnia because of body aches, heartburn, and frequent urination. Take short naps during the day to get some rest.
  1. Forgetfulness due to stress and hormonal changes.
  1. Round ligament pain as the abdominal ligaments and muscles stretch.
  1. Edema of the feet and hands, which swell due to water retention in the body. It is mostly benign but in some cases it might indicate protein deficiency, anemia, altered thyroid function or pregnancy-induced hypertension.
  2. Varicose veins because the growing uterus applies pressure on the on the veins that carry blood from your legs to the pelvic area, restricting proper flow.
  1. Hemorrhoids develop near the rectal area due to pressure exerted by the uterus on the veins. They are painful and itchy.
  1. Sciatica – when the growing uterus puts pressure on the sciatic nerves, you experience excruciating pain in the back and at the back of the legs.

While these are some of the health issues you might face in this week, there are also some other changes happening in your body and mind. Let’s see what they are.

Changes In The Body At 31 Weeks

Here are some physical and emotional changes that might occur in your body:

Physical changes

  • Due to the hormonal fluctuations, the nails become dry and brittle and could break easily.
  • Yellow liquid, called colostrum, starts leaking from the nipples.
  • The bump is bigger as the baby is growing in size. If you are carrying twins, then the belly looks more bulged. The linea nigra gets darker and prominent.
  • The areolas get darker, and the nipples become erect and hard.
  • The stretch marks are more prominent with the expanding belly.
  • The blue veins are visible around the breasts and the thighs, due to the increased supply of blood to these areas.

Emotional changes

  • Anxiety
  • Mood swings

So, how is the baby doing this week?

Fetal Movements And Position During The 31st Week Of Pregnancy

The baby movements will be strong this week, but the frequency of movements might reduce to some extent. Since the baby is growing, the space inside the uterus is not enough for the baby to move freely.

Your OB/GYN Visit

During your prenatal visit this week, the doctor will:

  • Advise a urine test to check the protein or sugar level
  • Check your blood pressure
  • Weight
  • Swelling of hands, feet and other parts of the body
  • Measure the size of the womb

In case you have gestational diabetes, an ultrasound may be done to check the fetal position and the development of the baby.

You are likely to have the below tests:

  • Fetal fibronectin (8): This test is performed to determine the possibility of a preterm. It is done if you have complaints of leaking or watery discharge or brownish mucoid discharge from vagina. The cervical fluid is analyzed for a glycoprotein called fibronectin, which is found between the amniotic sac and the uterine lining. A positive test result can be an indication of preterm labor or any other complications. However, a negative result can avoid unnecessary hospitalization.
  • Fetal Doppler study: This is an ultrasound study focusing on blood flow to the baby and growth restrictions, if any.

If the test results are normal and your doctor gives you a clean bill of health, all you need to do is follow a healthy diet and regimen for a smooth delivery.

Tips For Mom-to-be

  • Drink plenty of water and stay hydrated.
  • Stick to a healthy lifestyle and eat home cooked food. Include fish like pollock, salmon, shrimp, catfish, anchovies, and cod that are an excellent source of omega-3 fatty acids. Avoid shark, tilefish, king mackerel and swordfish as they contain high levels of mercury.
  • Quit smoking, drinking alcohol and excess caffeine intake.
  • Continue taking prenatal vitamin supplements like folic acid and iron.
  • Engage in moderate physical activities like walking. You can also consider Pilates to strengthen your pelvic floor and back muscles.
  • Keep stress at bay.
  • Get enough rest.
  • Do not take any medication without the doctor’s permission.
  • Wear loose, breathable clothes.
  • Maintain oral hygiene.
  • Avoid exposure to toxic chemicals.
  • Avoid cleaning cat litter to avoid toxoplasmosis.
  • Avoid strenuous activity.
  • Always sleep on your side.
  • Attend childbirth classes to prepare yourself for labor and delivery.
  • Carry fruits and snacks with you, if you are working and want to eat healthy when outside.
  • Spend more time with family and friends.
  • Start looking for baby names.
  • Read books, watch movies and do anything that makes you happy.

As you near the due date, handling everything on your own becomes difficult. When you need help, reach out to your partner.

Tips For Dad-to-be

Here’s what your partner can do:

  • Help with household chores by sharing the responsibilities.
  • Create a good environment at home.
  • Attend all the prenatal visits with you.
  • Plan for maternal shopping and outings.
  • Give you a good neck and foot massage.
  • Keep the medical documents and insurance papers handy.

Frequently Asked Questions

1. What position is the baby in at 31 weeks?

Most babies will lie vertically in the womb with their heads facing downwards at 31 weeks. It is the safest and most normal position for delivery (16).

2. How often should I feel the baby move at 31 weeks?

The expected count is about ten movements per hour. You may feel the baby kick, tap, or roll. If the count is less than ten, consult your Ob/Gyn to check on the baby (17).

At the 31st week of pregnancy, your baby will be developing fast. Skin will start looking smooth, their lungs are developing, and bones will be soft but fully developed. Their movements will be stronger but lesser in frequency as the space inside the uterus decreases. You may experience shortness of breath, frequent urination, backaches, and insomnia. Your nails may become dry due to hormonal changes, and blue veins may be visible on your breasts and thighs. You may also experience anxiety and mood swings. This is the time for you to stay relaxed, take adequate rest, and spend more time with friends and family.


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shreeja pillai

Shreeja holds a postgraduate degree in Chemistry and diploma in Drug Regulatory Affairs from the University of Mumbai. Before joining MomJunction, she worked as a research analyst with a leading multinational pharmaceutical company. Her interest in the field of medical research has developed her passion for writing research-based articles. As a writer, she aims at providing informative articles on health... more

Dr. Keeranmayee Mishra

Dr. Keeranmayee Mishra is an obstetrician and a gynecologist currently working at DRM Hospital, Mysore, Karnataka. She has been a gold medallist in her graduation and believes in constant upgrade of knowledge in the field of medicine. With over nine years of experience, Dr. Mishra specializes in infertility and PCOS.