Many congratulations to all wonderful mummies, as you have now entered in second trimester and already crossed about 1/3rd of your pregnancy. In this article about “week by week fetal development” you will learn about fetal development and changes going on in your body from week 14 to 17 i.e., 4th month of pregnancy. So, let’s have look on baby development and growth.

WEEK 14: Your little bundle of joy is developing very fast and is very active inside your womb and can respond to touch, squint, swallow, kick, stretch limbs and can make facial expressions. As your little baby is still small you cannot feel kicks at this point of time. Your baby has started peeing as his/her kidneys are now functioning. LENUGO are formed now i.e., fine hair on head, rest of the body and upper lips. If you are expecting a baby boy, then his prostate is developing and in case of baby girl, her ovaries which are in the abdomen are taking their place in pelvic now.

Baby’s length from head to bottom: 3.5 inches (roughly the size of a lemon), baby’s weight: 23g.

WEEK 15: Your baby’s facial features are very distinct but ears and eyes need further development. Ears are at lower side and will continue to move up at their final place whereas inner ear bones are still maturing. Hair of your baby started to appear and pigmentation has started now to give hair a colour. Baby’s movements are getting more and more defined and can make fists with little fingers now, but muscles and skeletal system need further development and maturation. Very rarely but some mothers do feel little kicks in week 15, especially if this pregnancy is third or fourth. This is very very rare though and most of the mummies feel kicks after 18 weeks. So, don’t worry about it.

15 weeks old fetus

Baby’s length: 4 inches i.e., approximately size of an apple, baby’s weight: 70g.

WEEK 16: As baby’s nervous system is developing very fast and skeletal system and muscles are getting stronger day by day and bones are getting more calcium and getting harder, your baby can now punch, kick with more strength and bounce in the amniotic fluid. You may not feel these gym activities now but soon you will😉 and now tiny fingers and toes also have tiny nails on them. Your baby’s head size is getting proportion with the body now. Baby’s heart is pumping around 23L  blood every single day and will continue doing it until birth. Skin is still transparent and vessels are still visible through it.

Baby’s length: 4.6 inches, i.e., size of an avocado. Baby’s weight: 100g.

WEEK 17: Baby’s head is getting into proportion with the body, whereas, facial hairs are still growing. Eye lids are still closed at this point of time and bones are getting stronger and harder. Baby’s kidneys, circulatory system and sweat glands are working now. Baby is practicing breathing movements as amniotic fluid goes in and out of little lungs and now baby can have hiccups also. Baby’s umbilical cord is getting thicker and longer as well. Baby’s length: 4.5 inches. Baby’s weight: 140g.

17 week old fetus


Now, you are not looking like a pregnant woman but by the end of this months or next, a tiny bump can easily be noticed. Now this is the time you should start thinking about buying maternity clothes for extra comfort. Your uterus is approximately equal to the size of a cabbage. Well in most of the cases nausea and morning sickness is gone by now. This trimester is the most relaxing one, as in first trimester you were feeling morning sickness, nausea and other discomforts and in the third trimester you will be having a big bump and discomforts as well. In second trimester, bump is not big, hence, less back pain, less difficulty in sleeping and walking. Your appetite will start to increase by now on wards and around 55-60 % of pregnancy weight is gains in second trimester. You might be feeling heart burn and acidity because of relaxed digestive system muscles, frequent urination, fatigue, tender breast and dizziness along with increased saliva, vaginal discharge and nasal mucus. Best advices for mummies are, to eat small but frequent meals and drink plenty of water to prevent heart burn. If having backache, use a pillow as a support under the back. In case of frequent toilet trips, drink your required amount of water during the day and evening, stop drinking water 1 hour before going to bed, so that you don’t need to wake up to pee, by the time you sleep, your bladder is already empty. Well, this tip worked for me, I hope it works for u as well. Feeling fatigue is normal during pregnancy and also in second trimester, but it is far better than first trimester, you feel more energetic during this time.

To keep yourself relaxed and energetic and stress free, join the antenatal classes near your home, this way you can manage to make friends who are going through the same situation as you. Go out to the parks, join antenatal yoga or water exercises after taking advice from your health expert. As pregnancy in many mums to be come with mood swings, joining antenatal groups and socializing with friends will work like wonder and de-stresses your mind. These all problems, I myself experienced during my two pregnancies. At this time around or somewhere near 17-18 weeks, you might be having a midwife appointment for regular check-ups. Think about your birth plan, any queries regarding your pregnancy and your maternity leave form if you are working or paternity leave form for your husband to get days off after baby’s birth. Discuss all these things and take guidance with your midwife.

happy pregnant women are talking together at antenatal class at the hospital.

Hope you enjoy reading this article, check out the next one i.e., about what is going on inside your womb during 5th month of pregnancy. I hope your 4th month of pregnancy and rest of the months ahead will go well and you will enjoy your pregnancy journey and your adorable little baby afterwards.
















  1. Wow, that is amazing, though they are small at 14 weeks they can do quite a bit like stretch and kick. The second timester was hard for me. I was sick and was gaining the weight I was supposed to. It was a scary time. Pregnancy is an amazing time, the way the baby develops is so amazing to me. Thanks for this info, it is really interesting. You always have such interesting articles.

    • Hi Melissa, thank you so much for sharing your views on this article. It is really amazing that at this early stage of about 14 weeks and even earlier, fetus can stretch, but that stretching in involuntary though, even these involuntary movements are so amazing to see while having a scan. Isn’t it an amazing feeling…

  2. Hi Sarah, this is lovely, learning about everything that happens during this trimester really is interesting. You can really start to see the baby taking form even down to the to the tiny nails. Sweet :). It’s good to know that this is the most relaxing trimester where you need to be making the most of it by getting your sleep in while you still can, and feeling as healthy as possible before the birth. Thanks for the great post!

    • Hi Stefanie, thank you so much for sharing your comments about this article, It is really amazing to see and know about baby’s development and growth at every stage of pregnancy. It is only possible because of the scientific inventions like scans and monitors.

  3. That’s really in depth post about different phases of pregnancy for mother. Any mother who want to get to know about changes in her body and want to know different lifestyle habit adaptation, will be useful and exciting stuff for them.

    • Hi Ganesh, thank you so much for your views and appreciation. These articles are really helpful of expectant mothers to know about their baby’s growth and development.

  4. It is a miracle how a baby grows inside a mother’s womb. The fetus receives everything it needs without the mom having to do anything more than take care of herself. Doing yoga during pregnancy is something more recent. Back in the day (25 years ago), we are not expected to be so active to prevent miscarriage. But truly, pregnant women who are in good health should be active as tolerated. Great post! Thanks!

    • Hi Gigi, thank you so much for sharing your views with us, it is really a miracle that how baby grows inside the womb from a tiny cell to a fully grown human being.

  5. Sniff, sniff. I won’t get emotional. It’s amazing how the baby is a living developing human being. Urninating, developing hair. It’s all so amazing. I hate that it’s nine month – not because of the difficulty but – because it’s so long. As soon as I found out that my husband and I (mostly I) was having a baby, I wanted to have and hold the baby right away.

    • HI Lane, thank you so much or sharing your comments here , it is not only amazing but magical, absolutely magical, how a human being develop inside the womb. No words can exactly explain it…:)


Please enter your comment!
Please enter your name here