How Does the Fetus Develop – Second & Third Trimester
Once a woman enters the second trimester, she may find it easier than the first. Her nausea (morning sickness) and fatigue may lessen or go away completely. However, she will also notice more changes to her body. That “baby bump” will start to show as her abdomen expands with the growing baby. By the end of the second trimester she will even be able to feel she baby move!
The baby may suck its thumb now. By 14 weeks the baby will be about 9-10 cm long. Its body is now covered with a layer of fine hair called lanugo. By 16 weeks its face is becoming more human in appearance, although the chin is small and the mouth is quite wide. Between 16 and 24 weeks the mother should feel her baby move for the first time — it may at first feel like butterflies.
The rapid growth that the baby has been experiencing now begins to slow a little. By week 20 the baby measures about 18 centimetres from crown to rump and is half as long as it will be when born. The legs are now in proportion with the body and the fingernails are well developed. Faint eyebrows are visible. At this stage, a mother will feel her baby moving about a lot, often when she lies down. Between 18th to 20th week of pregnancy, anomaly scan is performed to ensure the structural development of the fetus is normal.
By 24 weeks the baby’s organs are fully formed. The baby now has the face of a newborn baby, although the eyes are rather prominent because fat pads are yet to build up in the baby’s cheeks. The eyelids are fused until weeks 25 to 26 when they open. The growth of the baby at this stage can be checked with fetal growth scan The skin is wrinkled, red and thin with little underlying fat. The skin is covered with a waxy substance called vernix, which protects it while it is floating in the uterus. The body is well muscled, but still thin. The baby has become better proportioned, with the size of the body catching up with the size of the head. The baby’s hearing is also well developed by this stage; the baby will respond to noise.
Third Trimester: Changes a Woman May Experience The third trimester is the final stage of pregnancy. Discomforts that started in the second trimester will likely continue, along with some new ones. As the baby grows and puts more pressure on the mother’s internal organs, she may find difficulty breathing and have to urinate more frequently. This is normal and once she gives birth these problems should go away.
By 28 weeks lanugo hair has almost gone and hair is present on the head. Fat is being deposited under the skin.
The baby is becoming plumper. By 30 weeks the toenails are present and by 32 weeks the fingernails have reached the ends of the fingers. The baby’s eyes will be open when the baby’s awake. By about 32 weeks the baby will have settled into a downward position as there is no longer enough room left in the womb for it to move about freely. The mother will feel occasional vigorous jabs of the baby’s arms and legs.
Sometime between 36 and 40 weeks, the baby’s head will engage — that is, the head will be lying just on top of your cervix. The lanugo hair that had covered the baby has now mostly disappeared, although some hair may remain low on the forehead, in front of the ears and down the centre of the back. The toenails should have reached the tips of the toes.
By full-term, the baby should weigh about 2.7 to 3.5 kg, although full-term babies can weigh anything from 2.5 to 5 kg, and measure 35 to 38 centimetres from crown to rump and 44 to 55 cm from the baby’s head to its toes. These are just average figures, though, and there can be wide variation in the measurements. So now, 38 weeks after conception, the baby has all its organs and body systems ready for the big moment when it is born into the world. Check here to know about development of the baby is first trimester.
All the information provided by Chennai Women’s Clinic and Scan Centre (CWC) through its video, blog series is strictly for informational purposes only and all content, including text, graphics, video, images and information, contained on or available through this web site are only general information about gynecology, obstetric ultrasound scan services, practices and standards and the same is intended for information purposes only.
Any video, audio or text content is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. The information provided by CWC should not be used to self-diagnose or self-treat any health condition. Always seek the advice of your physician or other qualified health provider on any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of some information/inference you may have gathered from any video, audio or text content published by CWC.
The medical information, on any platform (digital or print), created by CWC is provided “as is” without any representations or warranties, express or implied. CWC shall not be responsible or liable for the use of any advice or information that you may obtain through this web site as a substitute for professional medical advice, diagnosis or treatment.