You are now entering the third week of the second trimester and are probably enjoying your pregnancy more than before. But, there is no need to worry if you continue to experience the first trimester signs like morning sickness, insomnia, food aversions and metallic taste in your mouth into the second, especially if you are carrying twins. The pregnancy hormones responsible for most of these symptoms function differently in each pregnancy, making it unique in many ways.
Your baby is now developed enough to hear your heartbeat, breathing and speaking, as the bones in his ears begin to harden or ossify . Although the eyelids are still shut, the eyes can now sense light in unison . The taste buds begin to form at the same time .
The legs are gradually growing longer than the arms, coming in proportion with the head and rest of the body. The nails on the little fingers and toes are growing fast , while all the joints in his body are already developed enough to move .
The ears have now reached their final position while the eyes are almost at the front of your baby’s face . He continues to practice different facial expressions to give the muscles a proper work out. Lanugo, the fine layer of downy hair now covering the fetus’s back, shoulders, forehead and ears, will continue helping him retain body heat until there is enough fat in his body to keep him warm .
The fetal movement is gradually getting more complex with your baby curling those tiny toes while kicking and punching the legs and arms. He is also practicing swallowing, grasping and sucking so he can survive on his own after birth . Another new development this week is the frequent hiccups that come before the fetus starts practicing breathing . However, these hiccups do not make any sound as the fetal trachea is filled with amniotic fluid instead of air.
The fetus is almost as big as an apple or a navel orange with a length of 4 inches (10.16 cm), weighing around 2.5 oz (70.8 gm) .
Weight gain is a principal body change during this stage with most women gaining about 5 pounds by the 15th week. But, it is completely normal to gain a little more or less . It is quite normal to lose balance or trip a few times for no reason as your center of gravity is changing due to the growing belly . The pregnancy hormone relaxin continues to loosen your joints and muscles, making you a bit clumsy.
You are probably finally starting to feel pregnant (if you did not earlier) as the baby bump is finally starting to show enough for others to notice that you are carrying . However, do not get too concerned if you are not showing yet as each pregnancy is different.
An ultrasound image can show your baby grimacing, swallowing, moving his arms and legs and sucking on his tiny thumb  while you can still see the growing blood vessels through the thin skin . Your doctor will also perform a fetal Doppler to check your baby’s heartbeat. Although gender detection might be possible through an ultrasound at this stage, it is advisable to wait a few more weeks to get an accurate result.
This is the right time to talk to your doctor regarding the necessity of any screening tests. There are no routine exams for week 15, but women over 35 years of age and those with high risk pregnancies are usually prescribed to have certain tests to assess the fetal health at this stage . Multiple marker screening (blood test)  and amniocentesis are the common screening tests performed between the 15th and 20th weeks .
Amniocentesis can detect most of the chromosomal and genetic diseases , while the multiple marker is performed for measuring the alpha-fetoprotein (AFP) levels in the mother’s blood . Abnormally high AFP levels might indicate a neural tube defect (e.g. anencephaly, spina bifida) in the baby .
Published on June 17th 2014 by Pregmed Editorial Team.
Article was last reviewed on 13th August 2014.