Day 212 of 280, third trimester
You are 30 weeks and 2 days
Your baby now has a clear rhythm of sleeping and waking, which may mirror yours or be his own.
68 days until your due date
How and when your baby develops a sleep-wake cycle before birth is still something of a mystery. It isn't known whether your rhythms influence his, or whether he develops his own internal clock, perhaps triggered by the small amount of light that gets through the uterus in the last weeks. But brain scans show that by now he has very distinct periods of activity.
There's a clear cycle of quiet rest, sleep with rapid eye movements (REM), wakefulness with activity but no eye movement, and wakefulness with lots of activity and eye movement. His actions become more coordinated as activity links with rhythmic breathing, a faster heart rate, and eye movements.
His brain's electrical activity now shows patterns of sleep and wakefulness. An EEG would show that deep sleep, the quietest state, takes up almost half his time. Next most common is REM sleep, when children and adults dream, a time of great electrical activity; he may be still or moving a lot, so it's impossible to tell whether he's awake or dreaming. Oddly, the least electrical activity happens when he's most awake, and less than 10 percent of his time is spent truly awake at this stage.
Good to know
Stem cell collection
The blood in your baby's umbilical cord ("cord blood") is rich in stem cells, the building blocks of organ tissue, blood, and the immune system. Some parents store them privately, at a cost, in case their child or another family member needs them.
Studies have found them very effective in treating more than 70 diseases, including juvenile diabetes, cancers, heart disease, and brain injury. There's significant evidence that cord blood from a sibling or other relative is more effective than cells from an unrelated donor or bone marrow from relatives.
Storage can be expensive, so some women donate cord blood to public banks, where it's used to treat the patients who need it most. Talk to your doctor if you'd like to do this. Collection is easy and painless and could have life-saving benefits.
Appointments and key dates around now
- Whooping cough vaccineUsually around 20 weeks, best before 32 weeks
- RSV vaccineFrom 28 weeks
Read the full 30 weeks pregnant guide
This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.