Pregnancy week 17 can be one of the most exciting stages of the second trimester because you are entering the period when the first noticeable fetal movements may begin.

Inside the uterus, the fetus is growing rapidly and becoming increasingly active. The nervous system is gaining greater control over movement, the digestive system is functioning, the eyes can move behind closed eyelids, the mouth can open and close, and the fetus may react to loud sounds.

The pregnant person’s body is changing too. The uterus is moving farther upward and outward from the pelvis, the pregnancy bump may become more obvious, the placenta is growing, and the skin may begin stretching enough for stretch marks to appear.

Quick answer: At 17 weeks pregnant, the fetus is around 12 cm long from head to bottom, roughly the size of a pomegranate according to NHS guidance. The fetus can move its eyes behind closed eyelids, open and close its mouth, respond to loud sounds, and become increasingly active. Some people may begin to feel the first fluttering movements, although many will not feel them until later.

What Does 17 Weeks Pregnant Mean?

Pregnancy is normally dated from the first day of the last menstrual period (LMP).

At 17 weeks pregnant, conception usually occurred around 15 weeks earlier in a typical menstrual cycle.

You are firmly within the second trimester.

ACOG defines the second trimester as lasting from 14 weeks and 0 days through 27 weeks and 6 days.

This stage is characterized by:

• rapid growth;
• increasing fetal movement;
• further brain development;
• skeletal and muscular strengthening;
• continued organ maturation.

The major organ systems formed earlier, but they continue becoming more functional and sophisticated.

How Big Is the Baby at 17 Weeks?

The NHS estimates the fetus at around 12 cm long from head to bottom at week 17.

That is approximately the size of a pomegranate.

Exact fetal size varies according to:

• the precise gestational day;
• genetics;
• natural biological variation;
• measurement technique.

Fruit comparisons are only visual approximations.

Ultrasound measurements are more useful when assessing an individual pregnancy.

What Is Developing at 17 Weeks?

Week 17 begins a developmental period that ACOG groups with weeks 17–20.

During this stage:

• the brain region controlling motor movement is fully formed;
• the digestive system is working;
• ears, nose and lips become increasingly recognizable;
• lanugo spreads over the body;
• movement becomes increasingly coordinated.

These changes make week 17 distinct from earlier second-trimester weeks.

What Is Happening to the Brain?

Brain development remains extremely active.

ACOG notes that during weeks 17–20, the part of the brain responsible for controlling motor movements is fully formed.

This helps explain why fetal movements become increasingly coordinated.

The brain still has an enormous amount of development ahead.

Areas responsible for:

• sensation;
• learning;
• memory;
• complex movement;
• sleep patterns;

continue maturing throughout pregnancy and after birth.

What Does Motor Control Mean?

Motor control refers to the nervous system’s ability to organize movement.

The fetus has been moving for many weeks, but movement gradually becomes:

• stronger;
• smoother;
• more coordinated;
• easier to see on ultrasound.

This reflects increasing communication between:

• brain;
• spinal cord;
• nerves;
• muscles.

Is the Baby Moving at 17 Weeks?

Yes.

The fetus is actively moving inside the uterus.

Movements may include:

• kicks;
• stretches;
• turns;
• arm movement;
• leg movement;
• body rolls;
• hand-to-face movement.

Some of these movements can now become strong enough for the pregnant person to notice.

Can You Feel the Baby Move at 17 Weeks?

Possibly.

NHS guidance notes that some people may begin feeling fetal movement around this stage, although many notice the first movements between 18 and 24 weeks.

MedlinePlus also describes weeks 17–20 as a period when fetal movement known as quickening may first be felt.

Not feeling movement at 17 weeks is therefore completely normal.

What Is Quickening?

Quickening is the term used for the first fetal movements that the pregnant person can feel.

Early quickening may feel like:

• fluttering;
• bubbling;
• rolling;
• tiny taps;
• butterflies;
• gentle flicks.

At first, it may be difficult to distinguish fetal movement from normal digestive activity.

When Do Most People Feel Their Baby Move?

The NHS says many pregnant people first notice movement between 18 and 24 weeks.

Timing varies.

Movement may be noticed earlier if:

• you have been pregnant before;
• you are familiar with what fetal movement feels like.

It may be noticed later in a first pregnancy.

Placental position and individual anatomy can also affect how movement feels.

Is It a Problem If You Cannot Feel Movement at 17 Weeks?

Usually, no.

At week 17, many healthy pregnancies still have no clearly felt movement.

Formal movement patterns have not yet become established.

Do not compare yourself with someone who felt movement earlier.

If you have specific concerns based on your personal pregnancy history, speak with your healthcare professional.

Should You Count Kicks at Week 17?

No.

Formal kick counting is generally not appropriate this early.

Movements may still be:

• subtle;
• irregular;
• difficult to distinguish;
• inconsistent from day to day.

Your healthcare professional can tell you when awareness of a regular movement pattern becomes clinically useful later in pregnancy.

Can the Baby Move Its Eyes at 17 Weeks?

Yes.

The NHS states that the fetus can move its eyes at week 17, although the eyelids remain closed.

Eye development is continuing.

The eyelids stay closed to protect the developing eyes and reopen later in pregnancy.

Can the Baby See at 17 Weeks?

No, not in the way a newborn can.

Although the eyes can move, vision is still immature.

The visual system requires further development of:

• retina;
• optic nerves;
• brain pathways;
• eyelid function.

Meaningful visual responses develop later.

Can the Baby Open and Close Its Mouth?

Yes.

The NHS notes that the fetus can open and close its mouth at 17 weeks.

These movements contribute to ongoing development of:

• facial muscles;
• jaw movement;
• sucking reflexes;
• swallowing coordination.

Is the Baby Practicing Sucking?

Sucking motions have already begun during this developmental period.

MedlinePlus describes weeks 15–18 as a stage when the fetus makes sucking motions.

These are part of preparation for feeding after birth.

Effective newborn feeding eventually requires coordination between:

• sucking;
• swallowing;
• breathing.

Can the Baby Hear at 17 Weeks?

Hearing is developing rapidly.

The NHS states that the fetus may react to loud noises at week 17.

ACOG notes that hearing begins developing during earlier second-trimester weeks and becomes more functional through the 17–20 week period.

This does not mean hearing is fully mature.

How Can the Baby React to Sound?

A loud sound may trigger movement.

At this stage, sound travels through:

• maternal tissues;
• uterine fluid;
• amniotic fluid.

The fetal auditory system is still developing, so sound is not perceived exactly as it would be after birth.

Should You Play Music to the Baby?

There is no need to expose the abdomen to loud music.

Normal everyday sounds, talking and music in the environment are sufficient.

Avoid placing very loud speakers or headphones directly against the abdomen.

Fetal hearing is developing naturally without special stimulation.

What Is Happening to the Ears?

The ears are becoming increasingly recognizable.

ACOG notes that by weeks 17–20, the ears, nose and lips become recognizable on ultrasound.

Ear development involves both:

• visible external structures;
• complex internal hearing structures.

What Is Happening to the Face?

Facial development is increasingly refined.

Features such as the:

• nose;
• lips;
• ears;
• jaw;

become more distinct.

These structures may be increasingly recognizable on ultrasound as pregnancy progresses toward week 20.

Are Fingerprints Forming at 17 Weeks?

The NHS states that the baby’s fingernails are growing and that the developing fingers will have their own unique fingerprints.

Fingerprint patterns are established through fetal development and are unique even between identical twins.

They will continue becoming more defined as the hands develop.

Why Are Identical Twins’ Fingerprints Different?

Identical twins share extremely similar DNA, but fingerprint patterns are influenced by tiny differences in the fetal environment during development.

This means identical twins do not have identical fingerprints.

Fingerprint formation demonstrates that not every physical detail is determined by genes alone.

Is Lanugo Still Developing?

Yes.

ACOG notes that during weeks 17–20, fine downy hair called lanugo begins spreading over the body.

Lanugo is temporary fetal hair.

It eventually helps interact with the protective coating that develops over the skin later in pregnancy.

What Is the Baby’s Skin Like at 17 Weeks?

The fetal skin remains thin.

Very little fat has accumulated underneath it.

Over the coming months:

• skin thickens;
• fat increases;
• blood vessels become less visible;
• protective coatings develop.

These changes help prepare the fetus for life outside the uterus.

Are the Bones Still Hardening?

Yes.

Bone development and mineralization continue throughout the second trimester.

Earlier cartilage gradually becomes harder bone.

The skeleton is strong enough to support increasingly active movement but remains flexible and immature.

What Is Happening to the Muscles?

Muscles continue growing and strengthening.

MedlinePlus describes weeks 15–18 as a stage of ongoing muscle and bone development with increased movement and stretching.

As muscle mass increases, movements become stronger and eventually easier for the pregnant person to feel.

Is the Digestive System Working at 17 Weeks?

Yes, at a developing fetal level.

ACOG states that during weeks 17–20 the digestive system is working.

This does not mean the fetus eats or digests meals like a newborn.

Nutrients still come through the placenta.

The fetus also swallows small amounts of amniotic fluid as development progresses.

Does the Baby Swallow Amniotic Fluid?

Swallowing develops during fetal life and becomes increasingly coordinated.

Amniotic fluid swallowing contributes to development of the:

• digestive tract;
• swallowing muscles;
• kidneys and fluid balance.

MedlinePlus notes that swallowing is established during the later part of this developmental period.

What Is Happening to the Placenta at 17 Weeks?

The placenta continues getting larger as the fetus grows.

The NHS notes that the placenta:

• feeds the fetus;
• transfers oxygen;
• removes waste.

It continues increasing in size throughout pregnancy.

How Large Will the Placenta Become?

The NHS notes that by the end of pregnancy the placenta may weigh around 500 grams.

At week 17, it is still growing and adapting to meet increasing fetal demands.

What Does the Placenta Actually Do?

The placenta supports pregnancy by helping:

• deliver oxygen;
• transfer nutrients;
• remove carbon dioxide;
• remove metabolic waste;
• produce important hormones.

The pregnant person’s blood and fetal blood do not simply mix directly.

Exchange occurs across specialized placental tissue.

What Is Happening to the Uterus at Week 17?

The uterus is now moving farther upward and out of the pelvis.

The NHS notes that the waist may begin disappearing as the uterus expands, making pregnancy more visibly obvious.

The abdomen gradually changes shape as the uterus grows.

Is Your Pregnancy Bump Usually Visible at 17 Weeks?

Often, yes.

Many people are visibly pregnant by this stage.

However, bump size varies according to:

• body shape;
• height;
• abdominal muscle tone;
• previous pregnancies;
• uterus position;
• fetal position.

A small or large bump does not independently determine whether fetal growth is normal.

What Symptoms Are Common at 17 Weeks Pregnant?

Possible symptoms include:

• growing pregnancy bump;
• round-ligament discomfort;
• mild backache;
• constipation;
• heartburn;
• bloating;
• increased vaginal discharge;
• headaches;
• dizziness;
• leg cramps;
• breast changes;
• sleep difficulties;
• mild swelling;
• gum sensitivity.

Some people also begin noticing fetal fluttering.

Are Aches and Pains Normal?

As the uterus grows, it places increasing strain on:

• abdominal muscles;
• ligaments;
• lower back;
• pelvis.

Mild discomfort can occur.

The NHS notes that aches and pains may become more noticeable as the bump grows.

Severe or persistent pain needs medical assessment.

Is Back Pain Normal at 17 Weeks?

Mild back discomfort can occur as:

• posture changes;
• the abdomen grows;
• ligaments become more flexible;
• the body’s center of gravity shifts.

Helpful general measures may include:

• supportive footwear;
• good lifting technique;
• moderate activity;
• avoiding prolonged awkward posture.

Severe pain, weakness, numbness or other neurological symptoms should be assessed.

Is Round Ligament Pain Still Normal?

Yes.

The ligaments supporting the uterus continue stretching.

This can cause short episodes of:

• pulling;
• sharp discomfort;
• groin pain;
• side pain.

Sudden movement can make it more noticeable.

Seek medical advice for severe or persistent pain.

Are Stretch Marks Possible at 17 Weeks?

Yes.

The NHS notes that stretch marks may start appearing on areas such as:

• abdomen;
• breasts;
• thighs;
• buttocks.

They can appear pink, red, purple or brown depending on skin tone.

How Common Are Stretch Marks?

The NHS notes that stretch marks affect up to 8 in 10 women during pregnancy.

They are associated mainly with:

• skin stretching;
• hormonal changes;
• genetics.

They commonly fade after pregnancy but may not disappear completely.

Can You Prevent Stretch Marks?

No cream or oil can guarantee prevention.

Moisturizers may help skin feel more comfortable and reduce dryness, but genetics and the way skin stretches play major roles.

Be cautious with products making guaranteed “stretch-mark removal” claims.

Is Increased Vaginal Discharge Normal?

Yes.

White or milky pregnancy discharge can remain common in the second trimester.

Seek medical advice if discharge becomes:

• green;
• yellow;
• foul smelling;
• itchy;
• painful;
• associated with fever.

A sudden gush or continuing watery leakage should also be medically assessed.

What About Light Spotting?

The NHS lists light spotting among possible pregnancy symptoms but recommends seeking medical advice for pregnancy bleeding.

Bleeding can have several causes.

Contact a healthcare professional if bleeding occurs, particularly when it is:

• heavy;
• increasing;
• associated with pain;
• accompanied by dizziness or fainting.

Is Constipation Normal?

Yes.

Pregnancy hormones can slow intestinal movement.

General measures may include:

• adequate hydration;
• fiber-rich foods;
• regular appropriate activity.

Do not start herbal laxatives or unfamiliar medicines without checking pregnancy safety.

Is Heartburn Normal?

Yes.

As pregnancy progresses, reflux may occur because:

• pregnancy hormones relax digestive muscles;
• the growing uterus changes abdominal pressure.

Helpful habits can include:

• smaller meals;
• avoiding known trigger foods;
• remaining upright after eating.

Ask a healthcare professional about pregnancy-safe medication if needed.

Are Headaches Normal?

Headaches can still occur in the second trimester.

Possible contributing factors include:

• dehydration;
• stress;
• tiredness;
• caffeine changes;
• hormonal changes.

Severe or persistent headaches require more caution, particularly if associated with visual changes or feeling unwell.

Are Bleeding Gums Normal?

Pregnancy hormones and increased blood flow can make gum tissue more sensitive.

You may notice:

• swelling;
• tenderness;
• bleeding while brushing.

Continue gentle dental hygiene and attend dental care when needed.

Pregnancy does not mean routine dental health should be neglected.

Can Sleep Become Difficult?

Yes.

Even in the second trimester, sleep may be affected by:

• changing body position;
• frequent urination;
• heartburn;
• stress;
• vivid dreams;
• discomfort.

Good sleep habits and comfortable positioning may help.

What About Mental Health at 17 Weeks?

Mental wellbeing is an important part of pregnancy care.

The NHS notes that around 1 in 5 women experience stress or anxiety during pregnancy.

Pregnancy anxiety may involve worries about:

• fetal health;
• scans;
• childbirth;
• finances;
• relationships;
• parenting.

These concerns deserve support rather than dismissal.

When Should You Ask for Mental Health Support?

Speak with your healthcare professional if anxiety or low mood:

• persists;
• interferes with sleep;
• affects daily functioning;
• causes panic;
• makes it difficult to cope.

Perinatal mental-health support is part of healthcare.

Is It Normal to Worry About Not Feeling Movement Yet?

Yes.

Week 17 sits at the beginning of the period when movement may become noticeable.

Many people still feel nothing.

The NHS notes that most first movements are identified between approximately 18 and 24 weeks.

Try not to use another person’s pregnancy as your benchmark.

What Prenatal Care Happens Around Week 17?

Appointment schedules vary.

Around this stage, prenatal care may focus on:

• blood pressure;
• urine checks;
• earlier screening results;
• maternal symptoms;
• fetal cardiac activity where appropriate;
• planning for the anatomy ultrasound.

If second-trimester screening has been chosen, that may also take place during this general period.

Is Second-Trimester Blood Screening Still Available?

Depending on the healthcare system and earlier screening choices, second-trimester serum screening may still be available.

Testing windows vary.

If you missed earlier screening or are unsure what tests you have completed, contact your prenatal healthcare provider rather than trying to combine screening tests yourself.

Is the Anatomy Scan Coming Soon?

Yes.

Week 17 is close to the time when many pregnancies are preparing for the mid-pregnancy anatomy ultrasound.

This detailed scan later evaluates structures including:

• brain;
• spine;
• heart;
• kidneys;
• abdomen;
• limbs;
• placenta.

Your healthcare system will specify the appropriate timing.

Can a 17-Week Ultrasound Show the Baby Clearly?

Yes.

At 17 weeks, many fetal structures can usually be seen.

An ultrasound may show:

• head;
• face;
• spine;
• arms;
• legs;
• hands;
• feet;
• cardiac activity;
• fetal movement;
• placenta.

However, a scan performed for one purpose should not automatically be considered a substitute for a complete anatomy scan.

Can the Baby’s Sex Be Seen at 17 Weeks?

Often it may be visible if:

• fetal position is favorable;
• image quality is good;
• external genital anatomy can be clearly seen.

However, fetal position can make determination difficult.

A later anatomy scan may provide another opportunity if parents want to know.

Can Ultrasound Detect Every Birth Defect?

No.

Even a detailed ultrasound cannot identify every possible:

• structural abnormality;
• genetic condition;
• developmental condition.

Screening tests and ultrasound reduce uncertainty but do not guarantee a completely healthy outcome.

This distinction is important when interpreting prenatal testing.

Is the Due Date Likely to Change at 17 Weeks?

If an accurate first-trimester ultrasound has already established the due date, later measurements generally should not cause repeated redating.

Small differences in fetal measurements can reflect normal variation.

Your healthcare professional decides whether any due-date change is medically justified.

Is Iron Still Important?

Yes.

Iron needs increase during pregnancy because maternal blood volume expands and fetal development requires iron.

Food sources include:

• lean meat;
• legumes;
• fortified cereals;
• leafy vegetables.

Some people require supplements based on blood tests or clinical history.

Do not self-prescribe very high doses.

Is Calcium Important at Week 17?

Yes.

Calcium supports:

• fetal bones;
• fetal teeth;
• maternal bone health;
• normal muscle function.

Sources may include:

• milk;
• yogurt;
• cheese;
• fortified alternatives;
• suitable plant foods.

Is Protein Important?

Yes.

Protein contributes to growth of:

• fetal tissues;
• placenta;
• uterus;
• maternal tissues.

Balanced protein sources can include:

• eggs;
• beans;
• lentils;
• suitable fish;
• lean meats;
• dairy;
• nuts.

Can You Exercise at 17 Weeks?

Many people with uncomplicated pregnancies can continue appropriate moderate exercise.

Examples may include:

• walking;
• swimming;
• prenatal exercise;
• moderate strength work;
• pregnancy-appropriate yoga.

Choose activity based on:

• prior fitness;
• comfort;
• medical history;
• pregnancy complications.

How Does Your Center of Gravity Change?

As the uterus grows, body weight shifts forward.

This can alter:

• posture;
• balance;
• walking mechanics.

Be cautious with activities carrying a higher fall risk.

Stable footwear and controlled movement become increasingly useful as pregnancy progresses.

Can You Travel at 17 Weeks?

Travel may be possible in an uncomplicated pregnancy.

The second trimester is often a relatively comfortable period for travel.

Before traveling, consider:

• medical care at the destination;
• insurance;
• infection risks;
• food and water safety;
• your pregnancy history.

Discuss complicated or high-risk pregnancies with your clinician before significant travel.

Is Sex Safe at 17 Weeks?

For most uncomplicated pregnancies, sexual activity is generally possible.

Seek individualized advice if you have:

• unexplained bleeding;
• leaking fluid;
• significant pain;
• placenta-related complications;
• instructions from your healthcare professional to avoid intercourse.

Should You Start Planning Where to Give Birth?

You can.

The NHS suggests that around this stage you may begin considering whether you prefer:

• a hospital;
• midwife-led unit;
• home birth,

where such options are available.

Options depend on:

• medical risk;
• local healthcare services;
• previous pregnancy history;
• personal preference.

Discuss available choices with your maternity team.

Is It Too Early to Think About Birth?

No.

You do not need a final birth plan at week 17, but learning about local maternity options early gives you time to:

• ask questions;
• understand available services;
• consider pain-relief options;
• discuss medical considerations.

Plans can change as pregnancy progresses.

When Should You Seek Medical Help at 17 Weeks?

Contact your healthcare professional whenever symptoms concern you.

Seek urgent medical assessment for:

• heavy vaginal bleeding;
• severe abdominal or pelvic pain;
• significant or continuous fluid leakage;
• fainting;
• severe dizziness;
• difficulty breathing;
• high fever;
• severe one-sided leg swelling or pain;
• persistent vomiting preventing hydration;
• other symptoms that feel urgent.

Online pregnancy information cannot diagnose potentially serious conditions.

Pregnancy Week 17 FAQs

How big is the baby at 17 weeks?

The NHS estimates the fetus at around 12 cm long from head to bottom, approximately the size of a pomegranate.

What is developing at 17 weeks?

The brain’s motor-control area is highly developed, the digestive system is functioning, fetal movement is becoming stronger, facial features become increasingly recognizable and lanugo continues spreading over the body.

Can you feel the baby move at 17 weeks?

Possibly. Some people begin feeling fluttering around this stage, but the NHS notes that many first notice movements between 18 and 24 weeks.

What does quickening feel like?

It may feel like fluttering, bubbles, rolling, tiny taps or gentle flicks.

Is it normal not to feel movement at 17 weeks?

Yes. Many healthy pregnancies still have no clearly felt movement at this stage.

Should you count kicks at 17 weeks?

No. Movements are not yet consistently strong or predictable enough for formal counting.

Can the baby hear at 17 weeks?

The auditory system is developing, and NHS guidance notes that the fetus may react to loud noises at this stage.

Can the baby move its eyes?

Yes. The eyes can move, although the eyelids remain closed.

Can the baby open its mouth?

Yes. The NHS notes that the fetus can open and close its mouth at week 17.

Are fingerprints developing?

Yes. Fingerprint patterns are developing and are unique even in identical twins.

Are stretch marks normal at 17 weeks?

Yes. They may begin appearing as the abdomen, breasts, thighs or buttocks grow. The NHS notes that they affect up to 8 in 10 women during pregnancy.

Can the baby’s sex be seen at 17 weeks?

It may be visible on ultrasound if fetal position and imaging conditions are favorable, though later scans can provide clearer visualization.

Is week 17 part of the second trimester?

Yes. The second trimester runs from week 14 through 27 weeks and 6 days under ACOG’s definition.

What Comes Next?

During Pregnancy Week 18, hearing becomes more established, fetal movement may become easier to notice, muscle and bone development continues, and many pregnancies move closer to the detailed mid-pregnancy anatomy ultrasound.

Previous: Pregnancy Week 16
Next: Pregnancy Week 18
Tool: Pregnancy Due Date Calculator

Medical References

This article is based on educational information from established medical organizations, including:

• NHS — 17 Weeks Pregnant
• American College of Obstetricians and Gynecologists (ACOG) — How Your Fetus Grows During Pregnancy
• ACOG — Changes During Pregnancy
• MedlinePlus — Fetal Development
• MedlinePlus — 17 Week Ultrasound

Editorial & Medical Information

Last content review: October 2026

This page provides general educational pregnancy information only. It does not diagnose pregnancy complications, assess fetal wellbeing, interpret ultrasound findings, prescribe treatments, or replace personalized prenatal care.

Fetal movement timing, symptoms, fetal size and medical needs vary between pregnancies. Contact a qualified healthcare professional for personal concerns about bleeding, pain, fluid leakage, screening results, medications, reduced wellbeing or other pregnancy symptoms.

Conclusion

Pregnancy week 17 is an important transition into the stage when fetal movement may begin becoming noticeable. The NHS estimates the fetus at around 12 cm from head to bottom and notes that the eyes can move behind closed eyelids, the mouth can open and close, and the fetus can react to loud sounds.

Neurological development is also progressing rapidly. ACOG describes weeks 17–20 as the period when the brain area responsible for motor control is fully formed and the digestive system is working. Facial features become increasingly recognizable, while lanugo spreads over the fetal body.

For the pregnant person, the growing uterus and placenta may make the pregnancy bump increasingly obvious. Stretch marks, mild aches, heartburn, constipation and sleep changes can occur, while some people may notice the first fluttering movements known as quickening.

Many people do not feel clear movement until 18–24 weeks, so lack of movement sensation at week 17 is usually expected.

Continue routine prenatal care and begin preparing for the mid-pregnancy anatomy ultrasound. Heavy bleeding, severe pain, significant fluid leakage, fainting, high fever or other serious symptoms require professional medical assessment rather than online self-diagnosis.