You are entering a stretch where time can feel elastic. Some days race, others stretch slowly, and the body writes its own script. The third trimester of pregnancy is where growth accelerates, lungs and brain fine tune, and practical plans turn into action. You might be excited, a little tired, sometimes both on the same afternoon. You want clear steps, not noise. Here you will find what to expect each week, how to read your baby’s signals, what tests mean, how to care for your body, and how to prepare for labor and the first days at home.
what the third trimester is and why it matters
The third trimester of pregnancy begins around 28 weeks and continues until birth. Babies gain most of their weight now, neural connections multiply rapidly, and antibodies move across the placenta to boost newborn defenses. Care often becomes more frequent, decisions feel closer, and routine monitoring helps confirm that the baby is thriving.
You may be wondering, what exactly tells us the baby is ready for the outside world, and what can I do today to feel better, sleep better, and prepare with confidence. The answers are practical, evidence based, and kinder than you might think.
third trimester fetal milestones, week by week
weeks 28 to 32, early third trimester
what baby is doing
Brain growth surges, sleep and wake cycles begin to show rhythm, and the lungs start making surfactant, a soapy substance that keeps tiny air sacs from collapsing after the first breaths. Many babies respond to voices, light, and gentle touch. If you like, read a short story aloud each evening. Repetition can be soothing.size and care insights
Average weight approaches 0.9 to 1.1 kg by 28 weeks and rises steadily. Babies born in this window often need help with breathing and feeding, neonatal teams are skilled at this.what you may notice
Movements feel stronger, sometimes rolling or stretching rather than flicks. Your team may talk about fetal movement counting and iron status. If a scan is scheduled, a prenatal ultrasound may look at growth and placental position.
weeks 33 to 36, mid third trimester
what baby is doing
Motor and sensory pathways refine. Lungs practice breathing movements, more surfactant is produced, and fat stores increase for better temperature control after birth. Babies often settle head down, called cephalic presentation. If the baby stays breech at 36 to 37 weeks, your clinician may discuss an external cephalic version that gently attempts to turn the baby.size and care insights
Many babies weigh 1.8 to 2.7 kg by the mid thirties. Space gets tighter, so kicks feel different, still, movement patterns remain a key sign of wellbeing.tests and planning
This is a common window for a Group B Streptococcus culture. A positive result leads to GBS prophylaxis with antibiotics during labor to protect the newborn.
weeks 37 to 40 plus, term and near term
timing definitions
Early term is 37 0 7 to 38 6 7 weeks, full term is 39 0 7 to 40 6 7 weeks, late term is 41 0 7 to 41 6 7 weeks, and post term is 42 0 7 or later. These intervals differ slightly in breathing readiness and feeding ease.readiness markers
Stable growth, reassuring fetal heart rate monitoring, active movement, practice breathing on scan, and an adequate amniotic fluid index. Close to birth, circulatory shunts prepare to close and the lungs are primed to expand.if birth happens now
Early term babies may need some feeding or breathing support. After 41 weeks, monitoring often increases and discussions about induction of labor may occur.
key organ systems and how they mature
nervous system
Cortical growth accelerates. Reflexes like rooting and sucking build foundations for feeding. Long periods of quiet sleep alternating with activity mark healthy cycles.lungs
Air sacs expand, surfactant levels rise, and the fetus practices breathing motions. These rehearsals, although no air enters, build muscle tone for the first breaths.circulation
Before birth, blood flow uses special pathways that divert to brain and heart. After birth, those pathways close as the lungs take over oxygen exchange. On monitors, patterns like variability and accelerations suggest a well oxygenated baby.immune transfer
Maternal IgG antibodies cross the placenta most intensely now. Timely Tdap vaccination and seasonal immunizations support this transfer for early newborn protection.
your body in the third trimester, symptoms, comfort, and red flags
common changes and simple relief
swelling
Mild maternal edema in ankles and hands is common. Elevate legs, stay hydrated, and consider compression stockings after medical advice.back and pelvic discomfort
Ligaments soften, posture shifts, and the pelvis carries more load. Try a support belt, gentle stretching, short walks, and a pillow between the knees for sleep.breathlessness
The uterus lifts the diaphragm. Slow down your pace, sit upright after meals, and practice nasal breathing if it helps.heartburn
Smaller meals, fewer acidic or spicy foods, and raising the head of the bed can help. Antacids may be used, check with your clinician first.frequent urination
Normal with increased bladder pressure. Pelvic floor exercises can support continence.tightening
Braxton Hicks contractions are irregular, usually fade with water and rest. They are different from progressive labor.skin and breast changes
Itchiness, stretch marks, and colostrum leakage can appear. Use gentle moisturizers and supportive bras.sleep shifts
Short naps, warm baths, and a calm evening routine can help you recharge.
You might ask, when is a symptom a signal to call. Good question. Any sudden shift that feels worrisome deserves a call for clarity and peace of mind.
warning signs that need prompt care
- decreased or absent movement
- a gush or steady leak of fluid, possible rupture of membranes or PROM
- vaginal bleeding or bloody show that seems heavy
- regular contractions before 37 weeks
- severe headache, vision changes, right upper abdominal pain, or sudden swelling, symptoms concerning for preeclampsia
- very high blood pressure readings, seizures indicate eclampsia, this is an emergency
prenatal care, tests, and monitoring in late pregnancy
visit rhythm and routine checks
visit frequency
Often every two weeks from about 28 to 36 weeks, then weekly. High risk care uses a personalized schedule.what is checked
Blood pressure, weight, urine for protein and infection, fundal height, fetal heart rate, mood screening, and movement patterns.
screening and diagnostic steps
blood work
Hemoglobin and complete blood count help identify anemia. If Rh negative, repeat antibody screens and plan for Rh(D) immune globulin around 28 weeks to prevent sensitization.infections and glucose
Re screening for sexually transmitted infections may be considered. Gestational diabetes screening guides nutrition and delivery timing.
fetal surveillance and imaging
ultrasound and fluid
Growth scans and the amniotic fluid index help track trends rather than single numbers. If blood flow needs a closer look, your team may use Doppler velocimetry or an umbilical artery Doppler.acoustic and movement checks
A biophysical profile combines ultrasound observations, breathing motions, tone, movement, and fluid. Some centers also use a nonstress test, if a stress test is needed it is called a contraction stress test.
cervical checks and gentle options to get labor started
exams
Cervical dilation and effacement checks can begin near term when helpful.membrane sweep
A sweep may trigger prostaglandins locally, it can cause spotting and cramping.induction tools
Cervical ripening with prostaglandins or a balloon, followed by oxytocin to stimulate contractions, are common pathways. Your preferences matter and should guide the plan.
paperwork and planning
preregistration and consents
Completing forms ahead of time speeds admission and reduces stress.cord and delayed clamping
Cord blood banking requires planning, while delayed clamping can boost newborn iron stores.leave and logistics
Prepare work handoffs early and pack essentials so you can focus on labor.
vaccines, immunity, and preventive care
The third trimester of pregnancy is a strategic time to support both you and the baby through antibody transfer. A Tdap vaccination between 27 and 36 weeks helps protect against pertussis. Seasonal influenza and COVID vaccinations follow local guidance. Discuss timing if an RSV option is available in your region, especially between 32 and 36 weeks, since passive antibodies can reduce severe disease in the first months of life.
monitoring fetal movement and kick counts
Movement patterns are a simple window into how the baby is doing. Many parents start consistent checks around 28 weeks.
two hour count to ten
Lie on your side in a quiet room, then count distinct movements until you reach ten. Hitting ten within two hours reassures.one hour quick check
Count for one hour. Fewer than four or five prompts a repeat check after rest and hydration.
What if movement feels less than usual. First, drink water, rest on your left side, and try again for 15 to 30 minutes. If counts remain low, call your care team for an NST or a biophysical profile.
nutrition, hydration, and weight gain
The third trimester of pregnancy calls for steady fuel and smart choices.
weight gain
Targets depend on pre pregnancy body mass index. For many, weekly gain sits near 0.3 to 0.5 kg.nutrients that matter
Iron with vitamin C, calcium with vitamin D, DHA around 200 to 300 mg daily, choline near 450 mg, iodine, and continued folate. If iron constipates, add fiber and fluids, consider stool softeners after medical advice.food safety
Avoid high mercury fish, unpasteurized dairy or juices, and undercooked proteins. Alcohol remains off the list.everyday strategies
Small frequent meals support reflux control. Sodium reduction and leg elevation reduce swelling, keep hydration strong, not sparse.
safe exercise, pelvic floor, and perineal preparation
Movement supports circulation, mood, and sleep. If the pregnancy is uncomplicated, aim for about 150 minutes of moderate activity per week, walking, swimming, prenatal yoga, and light strength work count. Stop if you have bleeding, contractions, severe pain, dizziness, chest pain, or reduced movement.
pelvic floor care
Daily contractions, also called Kegels, help continence and support delivery. If you notice leakage or pain, a pelvic health physiotherapist can guide technique.perineal massage
Starting around 34 weeks may increase tissue elasticity. Use clean hands and lubricant, pause if it hurts, talk with your clinician if unsure.core and posture
Avoid intense crunches. Choose control based breathing and alignment exercises. If a gap around the midline bulges, ask about diastasis assessment.
preparing for labor, birth choices, and practical planning
The third trimester of pregnancy shifts focus to how you want to labor and who you want around you.
place and team
Consider medical backup, freedom to move, and comfort. If you had a prior cesarean, ask about VBAC pathways and safety.pain relief
Options include water, movement, breathing techniques, massage, TENS, nitrous, opioids, and epidural analgesia. Each has a role, the right fit depends on your goals and how labor unfolds.induction and operative delivery
If an induction is planned, steps usually start with cervical ripening and move to oxytocin. A cesarean section may be scheduled or unplanned based on how mother and baby are doing.special positions
If the baby is occiput posterior or in a transverse lie, position changes, patience, and targeted techniques may help rotation during labor.planning documents
A simple birth plan and a postpartum plan clarify preferences for skin to skin, delayed clamping, newborn medicines, and feeding support.
signs of labor and when to go in
How will you know it is time. True labor feels like regular contractions that intensify and draw closer together. They often start in the back, then wrap forward, and cause cervical change. Braxton Hicks contractions usually ease with rest and water.
water breaking
A gush or steady leak suggests rupture of membranes. Color, odor, and timing matter. Call your team.blood tinged mucus
A bloody show can precede labor yet does not set the clock.when to head in
Many teams use the 5 1 1 guide, contractions five minutes apart, lasting one minute, for one hour. Go sooner for heavy bleeding, severe pain, fever, or decreased movement.what to expect on arrival
Triage includes vital signs, fetal tracing, an exam to check if water has broken, and a cervical check when needed.
travel, work, and daily life late in pregnancy
The third trimester of pregnancy often comes with schedule juggling. Airlines commonly limit travel after 36 weeks, and a note may be required. On any long trip, walk frequently, hydrate, and use compression stockings if advised. Wear the seat belt with the lap section under the bump and the shoulder strap between the breasts and to the side of the abdomen. At work, request ergonomic tweaks, plan handoffs, and leave paperwork early to lower last minute stress.
complications, higher risk situations, and extra monitoring
Some pregnancies benefit from closer observation. The aim is early detection and timely care.
blood pressure disorders
Gestational hypertension means elevated blood pressure after 20 weeks without protein in the urine. Preeclampsia adds signs like proteinuria or organ effects. Seizures define eclampsia. Treatment ranges from monitoring and medicines to delivery, and magnesium may be used, called magnesium sulfate, to reduce seizure risk before and after birth.growth and placenta concerns
Intrauterine growth restriction refers to slower than expected growth based on fetal weight percentile. Fluid extremes, oligohydramnios or polyhydramnios, shape surveillance plans. Placental attachment issues, placenta previa or placental abruption, may change delivery timing. Blood flow checks with umbilical artery Doppler and Doppler velocimetry inform frequency of visits and birth plans. Your team will watch for placental insufficiency if concerns arise.fetal position
Breech near term invites discussion of an external cephalic version and the balance of planned vaginal birth versus cesarean section.special therapies
If preterm labor is suspected, lung maturation may be supported with steroids, and antibiotics are used when PROM or GBS concerns exist.
setting up for baby and the fourth trimester
The third trimester of pregnancy is a good time to prepare a safe sleep space, install the car seat, and choose a pediatric clinic for newborn visits. Practice a few latch positions if you plan to breastfeed. Line up simple meals and small supports for the first days, a friend who can grocery shop, a neighbor who can walk the dog, a short list of lactation contacts. If mood changes feel heavy or sleep does not repair your energy, ask for care early. Resources work best when used sooner rather than later.
practical checklists
week by week checklist, weeks 28 to 32
- confirm vaccine timing, including Tdap and flu season planning
- schedule visits and any growth scans
- begin pelvic floor exercises and refine sleep routines
- review iron intake and strategies to prevent constipation
- consider prenatal classes and a hospital or birth center tour
weeks 33 to 36
- finalize preferences for monitoring, mobility, and newborn medicines
- install and check the car seat
- plan the Group B Streptococcus culture
- check fetal position and discuss options if breech
- complete leave paperwork and pack essentials
weeks 37 to 40 plus
- track movement daily, quick counts and two hour ten counts as needed
- pack your bag, include chargers, snacks, and documents
- assemble a safe sleep space and stock basics
- discuss induction of labor preferences if the due date passes
medical notes for data lovers
tests you may hear about
biophysical profile, amniotic fluid index, fetal heart rate monitoring, umbilical artery Doppler, and contraction stress test. These tools cross check movement, tone, breathing practice, fluid, and oxygenation.positioning vocabulary
cephalic presentation means head down, occiput posterior means head down facing the front of the parent, transverse lie means sideways. These labels help choose techniques and delivery methods.medications and procedures
cervical ripening, prostaglandins, oxytocin, epidural analgesia, magnesium sulfate, cesarean section. Each has specific roles, benefits, and trade offs that your clinician can explain in clear terms.
frequently asked questions, quick answers
can I sleep on my back
Side lying improves blood flow later in pregnancy, especially the left side. If you wake on your back, simply roll to your side.what if I pass my due date
Many babies arrive within a week of the due date. Your team may increase monitoring and discuss induction of labor based on cervical readiness and your preferences.how common is heartburn now
Very. Hormonal effects on the esophagus and stomach valves combined with a growing uterus make reflux likely. Small meals and evening adjustments often help.is perineal massage safe
For most, yes after 34 weeks. Stop if painful and ask your clinician if you have specific concerns.will I know if my water breaks
A sudden gush or a steady trickle suggests rupture of membranes. Note the color and call your team to plan next steps.
The third trimester of pregnancy is a changing landscape, yet the path becomes clearer when broken into simple checkpoints, steady routines, and responsive care.
key takeaways
- the third trimester of pregnancy spans 28 weeks to birth, with rapid growth, antibody transfer, and steady lung and brain maturation
- track movement daily, both quick counts and two hour ten counts are useful, call if movement is lower than usual after rest and hydration
- common discomforts have simple supports, side lying sleep, hydration, fiber, gentle movement, and practical tools like pillows and compression
- routine care may include biophysical profile, amniotic fluid index, and blood flow studies, these tests help confirm that baby is well
- explore your preferences for pain relief, mobility, delayed cord clamping, newborn medicines, and feeding, write a brief birth plan
- if you notice signs of preeclampsia or preterm labor, seek care immediately
- prepare home basics early, a safe sleep space, a checked car seat, meals, and contact lists reduce last minute stress
- support continues after birth, lactation help, pelvic floor recovery, mood care, and pediatric visits are part of the plan
- for personalized tips and free health questionnaires for children, download the application Heloa, it offers tailored guidance you can put into action today
The third trimester of pregnancy is not a sprint and not quite a stroll. It is purposeful movement, steady questions, and timely care. You know your body and your baby’s rhythms better each week, and your team is there to back you up.
Questions Parents Ask
Is sex safe during the third trimester?
In most uncomplicated pregnancies, sex is safe right up until labor. It rarely causes harm and many couples continue intimate contact, though interest and comfort often change. There are a few situations where your care team may recommend avoiding intercourse — for example after your waters have broken, if you have unexplained vaginal bleeding, placenta previa, signs of preterm labour, or a medical instruction for “pelvic rest.”
If intercourse causes discomfort, try different positions that keep pressure off the bump, use extra lubricant, and focus on other forms of closeness (touching, massage, cuddling) that feel reassuring. If you’re unsure or worried, call your clinician — a quick check-in can ease anxiety and give clear, personalized advice.
What is baby “dropping” (lightening) and when does it happen?
“Lightening” means the baby has moved lower into the pelvis. Timing varies: first-time parents often notice it a few weeks before labour; in people who’ve already had children it can happen later or only during labour. You may feel less shortness of breath and less heartburn as the uterus shifts, but expect more pelvic pressure, increased need to pee, and walking that feels heavier.
All of this can be normal, but if you experience sudden changes in movement, severe pain, fever, or bleeding, contact your care team. If the new pressure is uncomfortable, try brief rest periods, pelvic support belts if recommended, and positions that relieve the pelvis — and remember that variations in timing and sensation are common and usually not a sign of a problem.
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