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.
Development of the fetus in 15th week of pregnancy
Sensory organ development
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.
How big is the baby in pregnancy week 15
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) .
Body changes during the 15th week of pregnancy
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.
What does 15 weeks pregnant look like?
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.
15 weeks pregnant ultrasound
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.
Screening tests and exams during pregnancy week 15
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 .
Signs and symptoms at pregnancy week 15
- Sharp abdominal pain as the growing uterus pulls on the muscles and ligaments supporting it (round ligament pain) 
- Lower back, joint and hip pain
- Breast changes in preparation of breastfeeding
- A little swelling, especially of the fingers, hands and feet due to water retention  and the hormone progesterone
- Nosebleeds 
- Flu-like symptoms and pregnancy rhinitis (e.g. congested or runny nose and cold) 
- Itchiness with rash over the belly, breast and back (due to the skin stretching to accommodate the growing uterus)
- Swollen and bleeding gum 
- Emotional changes (feeling happy or depressed for no apparent reason)
- Gas and bloating
- Skin becoming oilier with the pimple outbreaks from the first trimester clearing gradually 
- Mask of pregnancy or appearance of dark patches, mainly on the face (but can occur on other parts of the body as well) 
- Indigestion and heartburn
- Varicose veins (mainly on the legs due to the increased blood flow)
- Braxton Hicks contractions
- Feeling out of breath 
- Headaches, dizziness and fainting 
- Forgetfulness or ‘pregnancy brain’ (there is a lack of scientific evidence regarding the factors responsible for this symptom with pregnancy hormones being the suspected cause) 
When to call the doctor
- Sudden severe nausea and vomiting that interferes with you daily activities (increases the risks of weight loss and dehydration) 
- Having over 5 contractions at a steady rate (even if they just feel like Braxton Hicks) or having intense abdominal cramps and back pain along with the contractions 
- Vaginal bleeding or spotting along with symptoms like lower abdominal pain, period like cramps, dizziness or fainting
- Severe upper or lower abdominal pain that refuse to go away with time 
- Extreme constipation or persistent diarrhea with stomach pain
- Extreme fatigue, rapid heartbeat, palpitations, headache and vision changes (might indicate high blood pressure) 
- Thin clear or yellowish discharge (might indicate leaking amniotic fluid)
- Pain and burning during urination or sex, vaginal spotting, odorless egg-white discharge with fever or nausea (might indicate a kidney infection, UTI or yeast infection) 
Tips for a healthy pregnancy and baby
- Practicing better posture for sitting, standing, walking and sleeping on your side as it can prevent various aches and pains in later pregnancy when your belly gets bigger 
- Using sunscreen lotion to minimize the skin darkening (opt for an oil-free one if you are having oily skin problems) 
- Including lots of vitamin C rich fruits and vegetables in your daily diet as, it is necessary for the proper connective tissue formation in the fetus. Vitamin C also improves your body’s iron absorption capacity.
- Drinking plenty of purified, fresh tap water as it contains fluoride which is beneficial for the proper tooth and enamel formation of your baby 
- Consulting with your doctor regarding getting a flu shot to prevent conditions like flu and pneumonia while pregnant (side effects of a flu shot might include mild soreness and fever)
- Shopping for maternity clothes as they provide better support for your changing body
- Following a light exercise routine, practicing prenatal yoga, relaxation and breathing techniques 
- Maintaining proper oral hygiene (brushing twice and flossing once every day) to prevent serious gum infections 
- Following a diet rich in omega-3 fatty acids as it helps with the brain and retina development of your baby 
- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3046737/ [/ref]