Month 7: Third Trimester Begins
Weeks 28–32 of Pregnancy
Month 7 marks the start of the third trimester, with rapid brain development and increasing birth preparations.
Welcome to the third trimester, the final stretch of your pregnancy journey. Your baby is growing rapidly and becoming more aware of the world outside. While this trimester can bring new physical challenges, it is also filled with excitement as you prepare to meet your little one. Every kick and movement brings you closer to holding your baby in your arms.
What is happening this month
The seventh month marks significant developments in your baby's brain and sensory systems. Your baby is increasingly responsive to light, sound, and touch. You might notice patterns in their activity, perhaps more active after meals or in the evening. This is also when many women experience the nesting instinct and feel compelled to prepare their home for baby's arrival.
Week-by-week development
Baby can blink and has eyelashes. The brain can control breathing and body temperature with some assistance.
Baby's muscles and lungs continue maturing. The head is growing to accommodate the rapidly developing brain.
Baby's bone marrow has taken over red blood cell production. Vision is developing and baby can see clearly up close.
Baby can process information and track light. All five senses are now developed and functioning.
Baby's bones are hardening, except the skull which remains soft for delivery. Fingernails reach the fingertips.
Your baby's development
By the end of month 7, your baby has grown to about the size of a large aubergine (35–38cm) and weighs approximately 1–1.2kg. Major developments include:
- Eyes can open, close, and blink, and baby may see light through your belly
- Brain waves show rapid eye movement (REM) sleep, meaning your baby is dreaming
- Taste buds are developed and baby shows preferences for certain flavours
- Lungs continue maturing but would still need support if born now
- Baby is gaining weight rapidly, developing fat layers for temperature regulation
- Bone marrow has taken over red blood cell production
- Baby responds to your voice and may recognise familiar sounds
- The nervous system is developed enough to control some body functions
- If born now, baby would have a good chance of survival with initial medical support
Size comparison
Your baby is about the size of a large aubergine
35–38 cm (14–15 inches) | 1–1.2 kgChanges in your body
The third trimester brings new physical challenges as your body works hard to support your growing baby. Remember, these symptoms are temporary and signal that your body is doing exactly what it needs to do:
Weight Gain
Expect to gain about 450g per week as baby grows rapidly
Heartburn
Growing uterus pushes the stomach upward, causing acid reflux
Shortness of Breath
Less room for the lungs to expand as baby takes up more space
Frequent Urination
Baby's head may press on your bladder, increasing bathroom trips
Sleep Challenges
Finding comfortable positions becomes harder; a pregnancy pillow can help
Lightning Crotch
Sharp pains in the pelvis as baby's head presses on nerves and your pelvis gradually widens
Important care tips
Increased monitoring
Your antenatal appointments become more frequent in the third trimester, typically every 2–3 weeks. Your healthcare provider will monitor your blood pressure, baby's growth, heart rate, and position. Do not skip appointments even if you feel well, as they are crucial for detecting any complications early.
Movement monitoring
Get to know your baby's normal pattern. If you notice a significant decrease or change in movement, contact your midwife or go to your maternity assessment unit immediately. Do not wait until the next day.
Important vaccinations
Get your whooping cough (pertussis) vaccine between weeks 27–36, ideally around week 28. This protects your baby in their first weeks of life. Also ensure your flu and Covid vaccines are up to date if you are pregnant during flu season. All three are safe and recommended in pregnancy.
Nesting and preparation
Start washing baby clothes, setting up the nursery, and packing your hospital bag. Do not overdo it though - delegate heavy tasks and take regular breaks. This is also a good time to install the car seat and ensure you know how to use it correctly.
When to contact your midwife, maternity unit or call 999
If you experience any of the following, contact your midwife or go directly to your nearest maternity assessment unit. In an emergency, call 999.
- Decreased or absent fetal movements
- Signs of preterm labour: regular contractions, pelvic pressure, or backache
- Vaginal bleeding or fluid leakage
- Severe or persistent headache
- Vision changes such as blurring, spots, or flashing lights
- Sudden swelling in face and hands
- Severe upper abdominal pain
- Persistent vomiting or inability to keep fluids down
- Calf or leg swelling or tenderness
- Shortness of breath, dizziness, or palpitations
Looking ahead
Month 8 brings you even closer to meeting your baby. Continue preparing practically and emotionally for birth and parenthood. You will have your next routine antenatal appointment around 32 weeks. Remember that every pregnancy is different. Some women feel energetic in the third trimester while others need more rest. Listen to your body, accept help when offered, and do not hesitate to discuss any concerns with your healthcare team. You are doing an amazing job.
Frequently asked questions
In month 7, you enter the third trimester. Your baby's brain develops rapidly, they can blink and have eyelashes, and all five senses are functioning. Baby weighs about 1–1.2kg and is the size of a large aubergine.
Common symptoms include heartburn, shortness of breath, frequent urination, sleep challenges, weight gain of about 450g per week, and lightning crotch pains as baby's head presses on nerves.
The whooping cough (pertussis) vaccine should be given between weeks 27–36, ideally around week 28. This protects your baby in their first weeks of life before they can be vaccinated themselves.
In the third trimester, antenatal appointments become more frequent, typically every 2–3 weeks. Your healthcare provider monitors blood pressure, baby's growth, heart rate, and position more closely.
Contact your midwife or go to your maternity assessment unit immediately if you notice a significant decrease in baby's movements or if the movement pattern changes dramatically from what is normal for your baby. Do not wait.
Yes, sleep challenges are very common in the third trimester as finding comfortable positions becomes harder. A pregnancy pillow can help, and sleeping on your side with support between your legs is recommended.
Start packing your hospital bag, set up the nursery, install and learn to use the car seat, and begin washing baby clothes. This is when the nesting instinct often kicks in, so channel that energy wisely.
Lightning crotch refers to sharp, sudden pains in the pelvis and vaginal area caused by baby's head pressing on nerves and your pelvis gradually widening to prepare for birth. It is normal but uncomfortable, and usually passes quickly.
