Pregnancy Week 38
Pregnancy Week 38
What to expect on pregnancy week 38
Pregnancy Week 38 is an early-term stage close to the estimated due date. The fetus continues maturing, toenails have reached the tips of the toes, most lanugo has disappeared and fetal movement remains an important sign of wellbeing.
Pregnancy Week 38 Overview
At Pregnancy Week 38, the fetus has an increasingly newborn-like appearance and is getting very close to the estimated due date.
Mayo Clinic identifies several useful developmental milestones this week: the head and abdominal circumferences are approximately similar, the toenails reach the tips of the toes and most of the fine lanugo hair has disappeared.
Despite this advanced development, the brain, lungs and nervous system continue important maturation.
Is Pregnancy Week 38 Full Term?
Some patient-facing pregnancy resources use “full term” for Week 38. However, ACOG and the Society for Maternal-Fetal Medicine use more specific gestational-age categories.
| Stage | Gestational Age |
|---|---|
| Early Term | 37 weeks 0 days through 38 weeks 6 days |
| Full Term | 39 weeks 0 days through 40 weeks 6 days |
| Late Term | 41 weeks 0 days through 41 weeks 6 days |
| Postterm | 42 weeks 0 days and later |
How Big Is the Fetus at Pregnancy Week 38?
The NHS describes the Week 38 fetus as approximately 49.8 centimeters from head to heel.
The NHS compares this length with a stick of rhubarb.
Mayo Clinic gives an approximate Week 38 fetal weight of 2,900 grams, or about 6½ pounds.
Mayo also emphasizes that fetal size varies considerably, so this number should not be treated as a required target.
Head and Abdominal Circumferences at Week 38
Mayo Clinic identifies an interesting Week 38 developmental change: the measurement around the fetal head and the measurement around the abdomen are now approximately similar.
This reflects the changing proportions of the fetus as the body gains fat and becomes progressively fuller.
It does not mean that every fetus has exactly identical head and abdominal measurements.
Ultrasound measurements vary naturally and must be interpreted in clinical context.
Toenails Reach the Tips of the Toes
Mayo Clinic specifically identifies toenails reaching the tips of the toes as a Week 38 milestone.
Toenail formation began much earlier in pregnancy, so Week 38 is not the beginning of nail development.
Instead, the nails have continued growing as the fetus matured.
Most Lanugo Has Disappeared by Week 38
Lanugo is the soft, fine hair that covered much of the fetal body earlier in pregnancy.
Mayo Clinic states that by Week 38, most of the lanugo is gone.
The NHS similarly notes that the furry coat seen earlier in pregnancy has mostly disappeared.
Some babies can still be born with small patches of lanugo, so its complete absence is not required.
Meconium Is Present in the Fetal Bowel
The NHS notes that meconium is accumulating in the fetal bowel during late pregnancy.
Meconium is the baby's first stool and contains material swallowed during pregnancy, including components of amniotic fluid and shed cells or fine hair.
It is normally passed after birth.
Brain Development at Pregnancy Week 38
The brain remains actively developing even though the fetus looks highly mature externally.
ACOG states that during Weeks 37 through 40 the brain and nervous system continue finishing their development.
Neurological maturation supports breathing coordination, swallowing, movement, sensory processing, sleep-wake activity and many other functions.
Brain development will continue after birth and throughout childhood.
Lung Development at Pregnancy Week 38
The lungs are highly developed by Week 38 but continue maturing.
ACOG includes the lungs among the systems that are still finishing development during Weeks 37 through 40.
Surfactant development has progressed substantially and supports the air sacs when breathing begins after birth.
Inside the uterus, oxygen continues reaching the fetus through the placenta rather than through air breathing.
Circulatory and Musculoskeletal Development
ACOG describes the circulatory and musculoskeletal systems as having completed their major fetal development during the Weeks 37 through 40 period.
The placenta still provides oxygen and nutrients until birth.
After delivery, major circulatory changes occur as placental circulation ends and the newborn begins breathing air.
Bones and muscles continue growing and changing after birth even though major prenatal musculoskeletal development is advanced.
Fetal Movement During Pregnancy Week 38
The fetus occupies a large amount of space inside the uterus at Week 38.
Movements may therefore feel different from earlier pregnancy.
You may notice stretches, rolls, pushes, wiggles and strong localized pressure rather than large flips.
However, fetal movement should continue.
Baby Position at Pregnancy Week 38
Most fetuses are in a head-down position by Week 38.
Some heads may already be engaged deeper in the pelvis, while others remain higher until labor begins.
The precise position can affect how pressure feels in the pelvis, bladder, ribs and abdomen.
If the fetus remains breech or transverse, your healthcare team can discuss the delivery plan based on your individual circumstances.
Maternal Changes During Pregnancy Week 38
At Week 38, many symptoms are continuations of previous third-trimester weeks.
The NHS lists possible symptoms including Braxton Hicks contractions, sleeping problems, backache, indigestion and heartburn, constipation, leg cramps, dizziness and swelling.
Vaginal discharge may also increase as the cervix and lower reproductive tract prepare for birth.
Some people feel physically tired, impatient or uncomfortable as the estimated due date approaches.
What Happens at a 38-Week Prenatal Appointment?
Appointment schedules vary by healthcare system and individual pregnancy needs.
The NHS includes a routine 38-week antenatal appointment.
At this visit, care may include:
Blood pressure is checked to help identify pregnancy-related hypertension.
Urine may be checked for protein or other findings that need attention.
The uterus may be measured to follow the pattern of pregnancy growth.
The abdomen may be examined to assess how the fetus is positioned.
The baby's normal activity pattern and any changes may be discussed.
Options if pregnancy continues beyond the due date may be discussed.
Preeclampsia Awareness at Week 38
Preeclampsia can occur during the second half of pregnancy and can also develop after delivery.
This is one reason blood pressure and urine testing remain important in late-pregnancy care.
High blood pressure can sometimes occur without obvious symptoms, so attending prenatal appointments remains important.
Signs That Labor May Be Beginning
Labor may begin around this stage, although there is no way to predict the exact day.
ACOG describes several changes that may signal labor.
The fetal head may move lower and settle deeper into the pelvis.
Clear, pink or slightly bloody mucus may appear as the cervix changes.
Amniotic fluid may appear as a gush or persistent trickle.
True labor contractions generally develop a pattern and become closer together.
Braxton Hicks vs True Labor Contractions
Braxton Hicks contractions can continue at Week 38 and may sometimes feel strong.
ACOG notes that true labor contractions generally occur at regular intervals and become progressively closer together.
They also tend to become stronger over time.
False or practice contractions are generally less regular and may settle after rest, hydration or a change in position.
Mucus Plug and “Bloody Show”
A thick mucus plug develops at the cervix during pregnancy.
As the cervix begins to open, some or all of this mucus may pass into the vagina.
ACOG describes the discharge as potentially clear, pink or slightly bloody.
Losing the mucus plug does not predict exactly when birth will occur.
What If Your Waters Break at Week 38?
Rupture of membranes occurs when the amniotic sac breaks.
Fluid may appear as a noticeable gush or a slower persistent trickle.
It can sometimes be difficult to distinguish amniotic fluid from urine or vaginal discharge.
Group B Strep Around Pregnancy Week 38
Group B Streptococcus, or GBS, is a common bacterium that may be present in the vagina or rectum without causing illness.
ACOG patient guidance describes routine GBS culture testing as being done between 36 and 38 weeks.
More detailed ACOG obstetric guidance specifies a standard screening window of 36 weeks 0 days through 37 weeks 6 days.
If you have not been screened or do not know your GBS result, ask your prenatal healthcare professional what applies to your pregnancy.
If GBS is detected, antibiotics are usually given during labor rather than routinely before labor.
Vaccination Considerations at Pregnancy Week 38
Vaccination timing differs substantially between countries and healthcare systems.
United States
Under ACOG's 2026 maternal immunization schedule, the usual Tdap window is 27 through 36 weeks.
ACOG's U.S. maternal RSV vaccination window is 32 weeks 0 days through 36 weeks 6 days for eligible pregnancies using seasonal administration.
Therefore, Pregnancy Week 38 is outside those routine gestational windows under current ACOG U.S. guidance.
United Kingdom
The NHS Week 38 guide states that RSV vaccination is usually offered earlier in pregnancy but may be given later if needed, including up until labor.
Possible Pregnancy Week 38 Symptoms
Irregular practice contractions may continue.
A large abdomen, bladder pressure and discomfort can disrupt rest.
Posture and pelvic changes can contribute to back discomfort.
Reflux may continue, although some people notice improvement after lightening.
Calf and foot cramps may continue, especially at night.
Mild swelling can occur, but sudden face or hand swelling needs attention.
A low fetal head can increase pressure on the bladder and pelvis.
Vaginal discharge or mucus changes may become more noticeable.
Planned Birth and Week 39
The timing of a planned birth depends on the medical reason, pregnancy history and healthcare system.
The NHS notes that a planned or elective caesarean is generally scheduled when pregnancy is at least 39 weeks when there is no reason that an earlier birth is needed.
Individual medical circumstances can require earlier delivery, so birth timing should always be decided with the healthcare team.
Healthy Choices During Pregnancy Week 38
Continue Eating a Balanced Diet
Choose a varied diet with vegetables, fruit, whole grains, protein foods and other nutrient-rich choices appropriate for your individual needs.
Stay Hydrated
Drink fluids regularly according to your activity, climate and medical circumstances.
Stay Active When Appropriate
Pregnancy-appropriate movement such as walking may support mobility and wellbeing if your healthcare professional has not advised restriction.
Keep Your Maternity Information Accessible
As labor can begin unpredictably, keep contact information and relevant maternity records easy to access.
Prioritize Rest
Late pregnancy can be physically demanding, so balance preparation for birth with adequate rest.
Continue Prescribed Medicines
Do not stop prescribed medicines or change supplements without speaking with the healthcare professional responsible for your care.
Pregnancy Week 38 and Your Estimated Due Date
Pregnancy is conventionally dated from the first day of the last menstrual period.
Our Pregnancy Due Date Calculator can help estimate an expected delivery date using relevant pregnancy dating information.
At Pregnancy Week 38, approximately two weeks remain until a 40-week estimated due date.
That does not mean labor will necessarily begin exactly two weeks later.
ACOG notes that only about 1 in 20 pregnant people give birth on their exact estimated due date.
The due date is therefore best understood as a clinical estimate and planning reference rather than an appointment for birth.
Pregnancy Week 38 Development Timeline
Week 38 remains within the ACOG early-term period.
Mayo Clinic identifies this as a specific Week 38 milestone.
Only small patches of fine fetal hair may remain.
Stretches, rolls and pushes should continue despite limited space.
Important neurological and respiratory development continues.
Lightening, mucus-plug changes, regular contractions or waters breaking may occur.
What Happens After Pregnancy Week 38?
Pregnancy Week 39 begins the full-term period under ACOG terminology.
Mayo Clinic notes that the fetal chest continues getting larger and additional body fat forms across the body.
These fat stores help the newborn maintain body temperature after birth.
The brain, lungs and nervous system continue their final prenatal maturation as the estimated due date approaches.
Pregnancy Tools You May Find Useful
Estimate your expected delivery date using relevant pregnancy dating information.
Estimate the current gestational week from appropriate pregnancy dating information.
Estimate a possible conception date or range while recognizing natural biological variation.
See approximately how much estimated time remains until your due date.
When Professional Healthcare Guidance Is Important
Pregnancy week-by-week information is general education and cannot determine whether an individual pregnancy or fetus is developing normally.
Contact your maternity team if you think labor is beginning, your waters may have broken or you are unsure whether contractions are true labor.
Seek prompt assessment for heavy vaginal bleeding, severe constant abdominal pain, fever, fainting, significantly reduced fetal movement or other concerning symptoms.
Persistent severe headache, vision changes, sudden face or hand swelling, upper abdominal or shoulder pain, significant one-sided leg swelling, chest pain or severe difficulty breathing also needs professional assessment.
Pregnancy Week 38 FAQs
What happens during Pregnancy Week 38?
During Pregnancy Week 38, the head and abdominal circumferences are approximately similar, toenails have reached the tips of the toes, most lanugo has disappeared and the brain, lungs and nervous system continue important maturation.
How big is the fetus at 38 weeks?
The NHS describes the fetus as around 49.8 centimeters from head to heel at Pregnancy Week 38, while Mayo Clinic gives an approximate weight of 2,900 grams or 6 1/2 pounds.
Is Pregnancy Week 38 full term?
Under ACOG terminology, Pregnancy Week 38 is early term. Early term is 37 weeks 0 days through 38 weeks 6 days, while full term begins at 39 weeks 0 days.
Are the toenails fully developed at Week 38?
Mayo Clinic identifies toenails reaching the tips of the toes as a Pregnancy Week 38 milestone, although nail growth and normal variation continue.
Is lanugo gone at Pregnancy Week 38?
Most lanugo has usually disappeared by Pregnancy Week 38, but some babies can still have small patches of fine hair at birth.
Does fetal movement decrease at Pregnancy Week 38?
No. Movement may feel different because space is limited, but you should continue feeling your baby's usual movement pattern through late pregnancy and labor. Reduced or changed movement needs prompt assessment.
What are common signs of labor at Week 38?
Possible signs of labor include lightening, loss of the mucus plug, rupture of membranes and contractions that become regular, stronger and closer together.
What should I do if my water breaks at Week 38?
If you think your water has broken, contact your maternity or obstetric care team and follow their instructions, even if regular contractions have not started.
What happens at a 38-week prenatal appointment?
A 38-week prenatal appointment may include checking blood pressure and urine, measuring the uterus, assessing fetal position and movement, discussing wellbeing and reviewing options if pregnancy continues beyond the due date.
What happens during Pregnancy Week 39?
Pregnancy Week 39 begins the full-term period under ACOG terminology, while fetal body fat continues increasing and the chest, brain, lungs and nervous system continue preparing for life after birth.
Medical References and Further Reading
This Pregnancy Week 38 guide uses established medical and public-health guidance for general educational information.
Next: Pregnancy Week 39
Pregnancy Week 39 begins the full-term period. The fetal chest continues getting larger, additional body fat is added and the brain, lungs and nervous system continue preparing for life after birth.
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