The second trimester

Pregnancy is divided into three periods, called trimesters, each of which is about three months long. As pregnancy transitions into the second trimester, things may calm down a little bit. Nausea may decline, the risk of miscarriage decreases, and hopefully, your fatigue will be under control – even if iron deficiency might set in during your second trimester, causing tiredness and dizziness. Of course, the going will still be very tough for some people – as nausea and vomiting can last throughout pregnancy – but for most, the second trimester will offer some respite.

When does the second trimester start?

The second trimester begins week 14 and lasts for three months, through week 27. But there is no definitive consensus on the precise weeks, and you might read elsewhere that it starts or ends a week earlier.
Many people feel less tired, are no longer nauseous and have a chance to catch their breath. Some even experience physical bonuses, like lustrous skin and hair, and heightened libido. It’s also possible that the mental chaos of the first few months, in which feelings of anxiety, excitement and “I can’t believe it!” were all jumbled together, shift into a calmer emotional state. It’s a bit like your body guided the process so thoroughly that now you can rest for a while before the physical intensity of your third trimester. If you have the strength and energy to work out during your second trimester, that might be a good investment for the next part of pregnancy.

How does the baby develop during the second trimester?

The minutiae of baby's development are in full swing: the nails and facial features are starting to take shape; hair is growing; motor skills and reflexes are developing; and their proportions are gradually becoming more orderly. But some things fall into place after birth; for example, newborns have a very large head relative to the rest of the body. The brain also develops a great deal during the second trimester, and it is protected by a loosely joined skull that will come together over time. But the fontanelles, those large soft spots between the skull bones, will still be there for another two years after baby is born. During the second trimester, the baby grows from the size of a peach to the size of a turnip – quite a lot of progress. The first routine ultrasound takes place during the second trimester and provides a clearer sense of your due date: you might rewind or fast-forward your understanding of where you are in your pregnancy by a week or so. That said, very few babies (only about 5%) are born on the “right” day.

Please note that all information above is based on Swedish recommendations.