Your baby-on-the-way is approximately 4 inches in length now or about the size of an apple, measuring from crown to rump. By the end of this week, your baby will weigh a little around 2.5 ounces.
Taste buds have formed on your baby’s little tongue already and your baby’s digestive system is practicing moving food along in the intestines. Your baby’s pancreas is secreting insulin already now; at 15 weeks.
The bones in your baby’s body are becoming gradually harder and ossifying. Blood is beginning to form in your baby’s bone marrow, as his or her blood vessels continue forming; connecting to one another.
Blood vessels are clearly visible underneath the surface of your baby’s transparent skin. Even though your little one won’t be able to make any noises until after birth, his or her vocal cords are developing inside the voice box and are forming the larynx.
Your baby’s external genitalia have been continuing to develop and mature. It’s becoming easier to determine male from female this week. Gender is nearing the point where it can be identified during an ultrasound by a very trained eye. But, keep in mind that ultrasounds are not 100% accurate and can be wrong, especially this early in pregnancy.
Also around this time, boys prostate glands are developing and girls ovaries are descending from the abdomen into the pelvis. Your baby’s thyroid gland has matured, therefore hormone production is under way.
Since your baby’s diaphragm and central nervous system are developing and refining, it is not unusual for your little one to get a case of the hiccups now and then; beginning around this week. Occasional bouts of hiccups are completely normal and harmless to your baby. They rarely last long- usually not more than 5-15 minutes at a time.
These hiccups are most likely caused from your baby drinking and breathing the amniotic fluid, which causes the diaphragm to contract. Your baby is too small for you to feel these little rhythmic and repetitive “bumps”. Soon you’ll notice them and be able to distinguish between kicks and hiccups.
From this point on, if you have an ultrasound, you may very well catch your baby hiccupping on the screen. Sometimes hiccups can even be heard when your doctor or midwife is using a Doppler to listen to your baby’s heartbeat.
Your Body in Pregnancy
Your regular clothes may be getting too tight to wear, since your belly has most likely altered the way they fit now. You can probably feel your expanding uterus about 3-4 inches below your belly button because it’s popping out above your pubic bone. Your doctor or midwife will use the position of your uterus to check the progress of your pregnancy, during your prenatal visits, measuring the distance from the top of your pubic bone to the top of the fundus. You are losing your waistline and looking more and more pregnant with every week that goes by! If you put on maternity clothes now, it may be obvious to other people that you’re pregnant!
You may be starting to experience some constipation. The most common cause of constipation during pregnancy is hormones. Pregnancy hormones can be held responsible for relaxing your bowels muscles, causing them to work less quickly. Also, the added pressure that your uterus places on your bowels plays another role in making you constipated. This annoying problem may increasingly get worse as your due date draws closer. Some lucky women are completely unaffected by constipation, as all women’s bodies are different and react to pregnancy differently. Make sure you are getting an adequate amount of fiber-rich foods in your daily diet and you are drinking enough fluids. At least eight 8-ounce glasses of water a day is recommended.
During the second trimester, usually beginning around this week, heartburn may strike. Heartburn is the painful burning sensation you may be feeling off and on, which seems to be coming from your heart. It actually has nothing to do with your heart. In fact, it occurs when food from your stomach backs up into your throat (or esophagus). The acid from your stomach causes the burning feeling. In the third trimester, your growing baby pushing all of your internal organs upward can be partly to blame for heartburn. It may end up getting a little worse, before it gets better or goes away for good. Some tips for avoiding heartburn include: stay away from foods which are hot or spicy, remember not to eat right before you go to bed (give your food a minimum of two hours to digest before lying down), don’t lay flat (instead prop your head up with pillows) and when you eat; take small mouthfuls and chew your food thoroughly. Check with your doctor or midwife before taking any over-the-counter antacids, to make sure they are safe to take during pregnancy.