Day 145 of 280, second trimester
You are 20 weeks and 5 days
Your baby becomes more responsive and aware every day as his nervous system starts working more effectively.
135 days until your due date
By now, your baby can sense light, pressure, pain, and temperature. Sound is thought to be the first sense to develop, although taste buds are on the tongue from as early as 10 weeks. Nerves carrying pain, temperature, and light touch from the body reach the spinal cord and travel to the hypothalamus in the center of the brain, which passes signals on to another part of the brain so they can be recognized and trigger an emotional response. Many of these nerves need insulating myelin sheaths to conduct signals well, but these don't develop until much later: after 29 weeks in the spine and 37 weeks in the brain.
Painful stimuli cause a reflex (like pulling your hand away from something hot), which doesn't need the brain. For sensations to be felt consciously rather than as a reflex, nerves must connect the hypothalamus to the brain's gray matter. These connections are thought to work after 26 weeks, but their electrical activity may not show clearly on an EEG until 34 weeks.
Ask a Mum
This is my second baby. Is it worth going to prenatal classes again?
I think so. There were three years between my pregnancies, and a refresher course helped; some of the advice had even changed. My partner found it useful too. It's also a chance to meet other pregnant moms and share the experience, and as with your first pregnancy, you'll probably make some great friends.
Good to know
Wearing maternity hose
You may not fancy maternity hose, but they have their uses. They boost circulation and the return of blood to the heart, and may be recommended to prevent vein problems, especially if you have varicose or spider veins.
They also ease aching feet, mild swelling in the feet, ankles, and legs, and fluid retention, and can be especially helpful if you're on your feet a lot at work.
Thankfully, many brands are now sheer and pretty. You can get thigh-high, knee-high, or full-length styles, some that support your baby and uterus to take pressure off your back, and lighter ones for summer, when heat can make swelling worse.
Appointments and key dates around now
- 20-week screening scanBetween 18 and 21 weeks
- Whooping cough vaccineUsually around 20 weeks, best before 32 weeks
Read the full 20 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.