At 23 weeks pregnant you are in the second trimester, about 5 months along and into your sixth month, with about 17 weeks to go until your estimated due date.
At 23 weeks pregnant your bump is probably obvious, kicks may be getting easier to feel, and the to-do list is starting to grow. New aches often come with it.
Here is what major medical sources say about week 23: development, size, symptoms, tests, sleep and warning signs. Where the sources disagree, we print both.
Key Takeaways
23 weeks is the second trimester: about 5 months completed and into month 6, with about 17 weeks to go.
Kaiser Permanente puts the baby at about 12 inches and just over 1 pound; Mayo Clinic’s crown to rump figures are smaller.
Mayo Clinic says rapid eye movements begin and the lungs start making surfactant around week 23.
Glucose screening for gestational diabetes happens between weeks 24 and 28 (UPMC).
Regular or strengthening contractions, leaking fluid, bleeding or a baby who moves less need a call right away.
Table of Contents
23 Weeks Pregnant at a Glance
Quick Answer
At 23 weeks pregnant you are in the second trimester. You have finished about 5 months and are in your sixth month, with about 17 weeks to go. Kaiser Permanente’s ob-gyns put the baby at about 12 inches and just over 1 pound, and glucose screening comes next, between weeks 24 and 28 (UPMC).
23 weeks pregnant
What to know
Trimester
Second. UPMC, using the American College of Obstetricians and Gynecologists (ACOG) definition, says the second trimester starts at 14 weeks 0 days and ends after 27 weeks 6 days.
Month
About 5 months completed, so you are in month 6, counting 4 weeks and a few days per month. Months are a convention, not a medical unit.
Weeks to go
About 17 (40 minus 23, counted from the last menstrual period).
Baby’s size
About 12 inches long and just over 1 pound (Kaiser Permanente). See the size table for Mayo Clinic figures.
Common symptoms
Braxton Hicks tightenings, backache and sore hips, heartburn, leg cramps, stuffy nose or bleeding gums.
This week’s care focus
Getting glucose screening on the calendar and learning the preterm labor warning signs.
23 weeks pregnant: quick facts.
How the weeks are counted. Cleveland Clinic explains that your due date is 40 weeks after the day you started your last menstrual period (LMP), not 40 weeks after conception. That is why Mayo Clinic describes week 23 as “twenty-three weeks into your pregnancy, or 21 weeks after conception.” The standard calculation assumes a 28-day cycle, and Cleveland Clinic notes your due date may be changed after an ultrasound. If so, go by the adjusted dates.
23 weeks pregnant in months. Twenty-three weeks is 161 days, a little past five calendar months. Grouped into four-week months, week 23 falls in month 6. Providers track pregnancy in weeks, and Cleveland Clinic says only about 4% of babies arrive on their due date.
Your Baby’s Development at 23 Weeks
Source and timing
What it says is happening
Mayo Clinic, week 23
The baby starts to have rapid eye movements. Ridges form in the palms and soles that create the foundation for fingerprints and footprints.
Mayo Clinic, week 23
The lungs are starting to make surfactant, a substance that lets the air sacs inflate and keeps the lungs from collapsing and sticking together when they deflate.
Kaiser Permanente, week 23
The skin is still translucent. Over the next few months, fat deposits will fill out the body for a plumper look.
Mayo Clinic, week 22
Eyebrows and hair are visible.
Mayo Clinic, week 24
The skin is wrinkled and see-through, with a pink or red tint from blood moving through the vessels.
Fetal development around week 23, by source.
Can your baby hear you? Kaiser Permanente’s week 23 page says your baby can hear music and voices while in the womb. Mayo Clinic adds that by about week 25 your baby might move in response to familiar sounds, such as your voice.
How Big Is Your Baby at 23 Weeks?
Size figures online often look contradictory because they measure different things.
Source
Week
Length
Weight
Mayo Clinic
22
About 7 1/2 inches (190 mm), crown to rump
About 1 pound (460 g)
Kaiser Permanente
23
About 12 inches (method not stated)
Just over 1 pound
Mayo Clinic
24
About 8 1/4 inches (210 mm), crown to rump
More than 1 1/3 pounds (630 g)
Baby size around 23 weeks. Sources differ, so all are printed.
Mayo Clinic measures crown to rump (top of the head to the bottom of the tailbone, legs not included) and gives no week 23 figure. Kaiser Permanente’s page does not say how its 12 inches is measured. We have not converted either figure.
Size comparison. Kaiser Permanente’s ob-gyns describe a baby at week 23 as about the size of a large mango. Treat every figure here as an average.
23 Weeks Pregnant Symptoms
Mayo Clinic says many people have more energy in the second trimester, but new aches arrive with the growing uterus.
Symptom
What the sources say
What may help
Braxton Hicks
Mayo Clinic describes mild, intermittent belly tightening, more likely in the afternoon or evening, after physical activity or after sex.
Drinking fluids and urinating often (Mayo Clinic). Call if they become regular and keep getting stronger.
Backache and sore hips
UPMC says relaxing ligaments stretch to widen the pelvis for birth, which can make joints less stable and cause pain. Mayo Clinic adds the growing uterus.
Low-heeled, supportive shoes; resting one foot on a stool when you stand for a long time (Mayo Clinic).
Heartburn
UPMC says the growing uterus presses on the stomach and pushes acid up the esophagus, and hormones relax the esophagus muscles.
Avoid big meals close to bedtime (MedlinePlus).
Leg cramps
Mayo Clinic says they often happen at night.
Stretch your calves before bed, stay active and drink fluids (Mayo Clinic).
Stuffy nose, nosebleeds
Mayo Clinic links them to increased blood volume.
Saline drops or rinses, a humidifier (Mayo Clinic).
Bleeding gums
Mayo Clinic says gums may bleed when you brush or floss.
Salt water rinses and a softer toothbrush (Mayo Clinic).
Common symptoms at 23 weeks pregnant.
Discharge and urinary symptoms. Mayo Clinic says a clear or white, sticky discharge is typical. Call if it smells strong, changes color or comes with pain or itching. Mayo Clinic also says to seek care for painful or urgent urination, cloudy urine, fever or backache, possible signs of a urinary tract infection.
Practice tightenings or something more? Tightenings that become regular and keep getting stronger need a call; the preterm labor signs are in the last section. Our guide to what contractions feel like compares the types.
Swelling. Bring up any swelling at your next visit. Extreme swelling of the hands or face, or severe swelling, redness or pain of a leg or arm, is on the CDC urgent warning list below.
Mood. Mayo Clinic says depression and anxiety are common during pregnancy and suggests asking your care team for a referral to a counselor who works with pregnancy issues.
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UPMC says the second trimester is when you start to show and body changes become much more noticeable. Bumps vary a lot at the same week.
Belly measurements: UPMC says your provider will start measuring your fundal height, a measurement of your growing uterus, around week 24.
Skin: Mayo Clinic describes melasma (brown, tan or gray patches on the face) and the linea nigra, a dark line down the belly, which usually fade after birth. It also mentions stretch marks and advises sunscreen. UPMC adds that stretching skin can itch.
Appetite: UPMC says you need about 340 more calories a day in the second trimester. Ask what weight gain is right for you.
Feeling your baby move. UPMC says most people start to feel fetal movement around 20 weeks, though some feel it as early as 16 weeks. The sources in this guide do not give a set number of movements for this stage. If you have not felt movement yet, tell your provider. Movement that stops or slows is a CDC urgent warning sign.
Prenatal Care, Tests and Appointments Around Week 23
UPMC says second trimester prenatal visits are usually every four weeks. Mayo Clinic says your team checks your weight and blood pressure, measures fundal height, may listen to the heartbeat and may suggest ultrasounds or screening tests.
What
When
Details
Source
Glucose screening
Between weeks 24 and 28
An oral glucose screening test for gestational diabetes.
UPMC
Flu and COVID-19 vaccines
Respiratory virus season
UPMC says your provider will offer them during respiratory virus season. Mayo Clinic advises a flu vaccine in fall and early winter.
UPMC, Mayo Clinic
Care around 23 weeks, with the timing each source gives.
Glucose screening is coming up. Ask at your next visit which test your practice uses, whether you need to fast and how long to plan for.
A note on vaccines. Vaccine guidance during pregnancy has been changing. The details above reflect the UPMC and Mayo Clinic pages as read in October 2026. Confirm what is recommended for you with your provider.
What to Do This Week: A Simple Checklist
Put glucose screening on the calendar: it falls between weeks 24 and 28 (UPMC).
Save the warning signs: read the list at the end of this guide and save your provider’s after-hours number in your phone.
Stretch your calves before bed: and drink fluids through the day, which Mayo Clinic suggests for leg cramps.
Keep moving, gently: UPMC says you can keep exercising, switching to walking, swimming or other low-impact options if your back or hips hurt.
Start the planning list: Mayo Clinic suggests childbirth classes, choosing a pediatric provider, reading about breastfeeding, checking your employer’s parental leave policy and looking into child care.
Sleep at 23 Weeks Pregnant
Sleep tends to get harder as the bump grows. MedlinePlus lists the reasons: finding a comfortable position, bathroom trips, heartburn, aches, stress and dreams, and more baby activity at night.
Sleep position. MedlinePlus suggests trying to sleep on your side, saying that lying on your side with your knees bent will likely be the most comfortable position. It adds that many providers recommend the left side, and you can switch to the right if your left hip gets sore. Ask your own provider what they want you to do.
Use pillows for support: MedlinePlus suggests pillows under your belly or between your legs. See how to use a pregnancy pillow for setups that work.
Ease heartburn and bathroom trips: avoid drinking a lot of fluids or eating a big meal within a few hours of bedtime (MedlinePlus).
Keep a routine: go to bed and wake up at the same times, skip exercise right before bed and try a warm bath to relax (MedlinePlus).
MedlinePlus is direct about sleep aids: do not take any, including over-the-counter and herbal products, without talking to your provider first. Our guide to melatonin during pregnancy covers the questions to ask.
For Partners: How to Help at 23 Weeks
Come to appointments when you can: and help keep track of questions.
Help with sleep: build the pillow setup and be patient with night wake-ups.
Check in on mood: Mayo Clinic says depression and anxiety are common in pregnancy. Ask, listen and help line up support.
Looking Ahead: What Comes Next
Week 24: Mayo Clinic lists about 8 1/4 inches crown to rump and more than 1 1/3 pounds.
Weeks 24 to 28: glucose screening (UPMC).
End of week 27: the last week of the second trimester under the ACOG definition UPMC uses. Week 28 starts the third trimester.
Call any time something worries you. MedlinePlus says to contact your provider right away if you notice any of these preterm labor signs before your 37th week of pregnancy:
Spotting or cramps in your abdomen: (MedlinePlus).
Contractions with lower back pain, or pressure in your groin or thighs: (MedlinePlus).
More than 5 contractions per hour, or contractions that are regular and painful: or that get longer, stronger and closer together (MedlinePlus).
Fluid leaking from your vagina in a trickle or a gush: or your water breaks (MedlinePlus).
Bright red bleeding, or a thick discharge with blood in it: (MedlinePlus).
The CDC lists these urgent maternal warning signs and says to seek medical care immediately:
Your baby’s movement stopping or slowing: (CDC).
Severe belly pain that does not go away: (CDC).
A headache that will not go away or gets worse, changes in your vision, or dizziness or fainting: (CDC).
Extreme swelling of your hands or face: (CDC).
Severe swelling, redness or pain of a leg or arm: (CDC).
A fever of 100.4 F or higher: (CDC), or pain when urinating, which UPMC says could mean a urinary tract infection.
Trouble breathing, chest pain or a fast-beating heart: (CDC).
Severe nausea and throwing up, or overwhelming tiredness: (CDC).
Thoughts about harming yourself or your baby: (CDC).
If you cannot reach your provider quickly, go to labor and delivery or the nearest emergency room. For trouble breathing, chest pain, fainting or anything that feels like an emergency, call 911. This article is general education, not medical advice.
Frequently Asked Questions
How many months is 23 weeks pregnant?
About 5 months completed, which puts you in your sixth month. Twenty-three weeks is 161 days counted from the first day of your last period, a little past five calendar months. Charts that use four-week months call it month 6.
How big is my baby at 23 weeks?
Kaiser Permanente says a baby at week 23 is about 12 inches long and weighs just over 1 pound, about the size of a large mango. Mayo Clinic measures crown to rump, which leaves out the legs: about 7 1/2 inches at week 22.
What should I be feeling at 23 weeks pregnant?
Common symptoms include Braxton Hicks tightenings, backache and sore hips, heartburn, leg cramps at night, a stuffy nose and bleeding gums, according to Mayo Clinic and UPMC. UPMC says most people start to feel movement around 20 weeks. Tightenings that become regular and keep getting stronger, bleeding or leaking fluid are reasons to call your provider.
How often should my baby move at 23 weeks?
The sources in this guide do not give a set number of movements for this stage. UPMC says most people start to feel movement around 20 weeks, some as early as 16. The CDC lists a baby’s movement stopping or slowing as an urgent warning sign and says to seek medical care immediately.
Can my baby hear me at 23 weeks?
Kaiser Permanente’s ob-gyns say your baby can hear music and voices while in the womb at this stage. Mayo Clinic adds that by about week 25 a baby might move in response to familiar sounds, such as your voice. Talking or singing to your bump is an easy habit to start.
When is the glucose test during pregnancy?
UPMC says your doctor will give you an oral glucose screening test between weeks 24 and 28 of pregnancy to check for gestational diabetes. Some people are tested earlier because of their health history. Ask your provider whether you need to fast.
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