You are 21 weeks and 3 days

As well as using fat for growth and development, your baby is now starting to store it.

130 days until your due date

Until now, your baby has had little chance to store fat, because growth was the priority. Now she starts laying down a layer of fat under her skin, which becomes less see-through. The placenta supplies the fat: fats circulating in your blood are broken down in the placenta into free fatty acids and cholesterol, which pass into your baby's circulation and recombine into fats for storage or growth.

Fats are important for proper nerve and brain development. A layer of fat covers each nerve cell, insulating it from its neighbors and improving its connections with other nerve cells.

Focus on

Twins: Bill and Ben?

Choosing one name is hard enough, so if you're expecting twins, start thinking now. To avoid jokes at their expense, steer clear of obvious pairs like Jack and Jill or Holly and Ivy, and think about how the names sound shortened (William and Benjamin become Bill and Ben).

Consider names of similar length and difficulty, too; young Christopher may get discouraged struggling to spell his name while his twin Jack has no trouble.

Ask a Mum

Should we tell people the name we've chosen?

I'd advise against it. We told people at first and were upset by all the negative reactions: people told us about their bad associations with the name, or that they knew a cat or gerbil called that, which we didn't need to hear! Older relatives called it "odd" and offered lists of alternatives.

Keep it to yourselves until the baby is born and it's a done deal. It takes a bold person to question your choice once your baby has been named.

Explainer

Fading veins

Your baby's veins will become less visible as a layer of fat forms under the skin, making it less see-through than earlier in pregnancy.

As a matter of fact

Hawaiian names

In Hawaii, parents often choose names associated with beauty.

Examples include Nohea ("loveliness"), Leia ("child of heaven"), Maka Nani ("beautiful eyes"), Hiwalani ("the attractive one"), Pualani ("heaven's flower"), and Nani ("beautiful, pretty one").

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.