Baby’s lower limbs are now well-developed
Your baby’s movements start with uncoordinated flutters between 7 and 8 weeks of pregnancy, and progress to flips, jabs, and kicks in the second and third trimesters. You’ll probably begin to feel these movements between 16 and 22 weeks, and they may be strong enough for others to feel through your belly by around 24 weeks. Meanwhile, 10 tiny fingers and 10 tiny toes will have developed before the end of the first trimester.
Arms and legs
Between 5 and 6 weeks, your baby sprouts two flipper-like buds that will lengthen and grow into arms, and by 7 weeks, two additional buds form that will become his legs. Your baby’s hands and feet, which look somewhat like paddles at this stage, will form at the end of these buds.
Around 9 weeks, spaces for the elbow and knee joints appear as the limb buds lengthen. At 11 weeks, the limbs have become less flipper-like and your baby can bend his arms or legs. They’ll continue to lengthen, and as they grow, your baby’s hands will come closer together and can meet over his heart (a gesture you may eventually be able to witness in an ultrasound). Your baby’s feet, too, come closer to each other and may touch.
Nerves, bones, and muscles are also developing inside your baby’s limbs. Nerves are present by 7 weeks, and by 10 weeks they’re controlling the developing muscles. Bone-producing cells are also at work around this time, forming the arm and leg bones. These bones, and others in your baby’s body, will continue to grow after birth.
Fingers and fingernails, toes and toenails
At 8 weeks of pregnancy, your baby has webbing between her fingers and toes. During the next few weeks, the webbing will disappear and the fingers and toes will grow longer and less stubby. By 11 weeks, your baby will sport 10 distinct digits on her hands and feet.
Fingernails and toenails start to form by 14 weeks and are complete during the last trimester of pregnancy – fingernails by 34 weeks and toenails by 38 weeks. Despite being adorably tiny, fingernails may grow quite long while your baby’s still in your uterus – so much so that she may need her first nail trim soon after birth. Those little nails can be sharp!
The first movements your baby makes are more like spontaneous twitches and stretches. They start at about 7 to 8 weeks and are visible on an ultrasound exam. Because you can’t feel these movements, it’s pretty amazing to see on the ultrasound screen just how active your little embryo is!
Your baby’s movements become more purposeful at 12 weeks. At this stage babies are able to open and close their hands and curl their toes, and they can move their arms and legs – at first altogether and eventually limb by limb.
At 16 weeks, your baby will start moving and flexing her limbs in a more coordinated way as her nervous system continues to develop. You may start to feel your baby’s movements around this time, or it could take several more weeks. Plus-size pregnant women or women whose placenta is on the front wall of the uterus (called an anterior placenta) may take longer to feel the kicks. Other people can feel your baby’s movements by placing their hand on your belly – but not until a few weeks after you’ve felt movement from the inside.
By 30 weeks, babies spend most of their time sleeping, and while they’re catching some z’s they’re usually very still, so you won’t feel any movement. But they tend to sleep in short bursts – between 20 and 40 minutes at a stretch – so you might not notice a significant slowdown.
You may start to notice patterns in your baby’s movements. Some fetuses are more active during the afternoon and evening; others are more lively in the morning. It can be interesting to see whether your baby follows these same patterns after she’s born.