Fifth Month Being Pregnant:
Pregnancy Weeks 18, 19, 20, 21
By the middle of the fifth month of pregnancy (week 17 or 18 through 21) you have officially hit the halfway point. In just four and a half months your baby will arrive. This month is a continuation of the rapid growth your baby has already experienced. New body systems and organs begin to function while others continue to mature. As baby gets bigger you will really start to look and feel pregnant. You'll want to find yourself some comfortable maternity pants to wear for the next few months. Most of the new discomforts you'll experience this month are caused by the increased size and weight of the uterus and they should diminish once the baby is born.
The fifth month is very exciting because your baby is now big enough for an ultrasound to determine the gender. Most of the time ultrasounds are very accurate, so from this point on, you'll be able to plan for your little girl, or little boy if that's what's been determined. It may be wise, however, to get a few clothes for the opposite gender, just in case. Your baby's external genitalia formed during the fourth month. During the fifth month the development of the reproductive system continues. If you are having a boy his testicles will start to move down into his scrotum. If you're having a little girl, she already has six million egg cells, known as oocytes, in her ovaries (at birth she will have a little over a million oocytes), and her vagina will form this month.
Your baby's immune system will begin to function this month and will offer some protection from sickness and infection. The placenta will continue to play its role, however, and offer baby extra protection until birth. Your baby's kidneys have also completed their development and will begin to function as well. Urine will now pass through the kidneys before leaving her body. A fun development for baby is the development of her senses. By the end of the month she will have skin and touch sensitivity and will be able to taste the amniotic fluid when she swallows it. Her sight continues to mature and by the end of the month she can hear your heartbeat and loud sounds outside of the womb. You may even feel her jump, responding to the sounds.
By the end of this month your baby is close to nine inches long and weighs almost a pound. Hair, if she is going to have any, will start to grow this month. Her skin is pink and wrinkled because there is no fat beneath it. That will start to change this month as brown fat grows on her body. Brown fat doesn't store calories like regular fat. It actually helps keep a body's metabolism active. Because of its properties it will help your baby regulate her own body temperature.
To protect your baby's skin from the amniotic fluid a thick, lotion-like substance will start to form this month all over her body. This is called vernix. Not only does it protect baby's skin, but it also makes her skin very soft. The lanugo that began to form during the fourth month will help keep the vernix on her body.
Now that you are halfway through the pregnancy, the uterus is large enough that you will definitely look pregnant. The in-between look that so many women hate should go away this month, replaced by a defined pregnant belly. You will want to invest in some comfortable maternity pants, if you haven't already. The uterus has grown and is now as high as the belly button. If you weren't able to feel your baby during the fourth month, you will most certainly begin to feel her movements this month. Babies at this stage of development are very active, especially since they still have plenty of room for movement. You will definitely feel some of her kicks and punches as she bounces of the uterine walls.
As the uterus grows you are likely to experience some pelvic pain. Part of this is due to the extra weight, but most of the pain is caused by the relaxing and stretching of the pelvic area that occurs during pregnancy. The only reason you should worry about this is if it gets too painful for you to do your regular activities. The ligaments in your body are also stretching and relaxing, particularly those supporting your uterus. Because of the extra strain on these ligaments it's not uncommon for women to feel sharp pains in the side of the abdomen or even toward the back, especially when moving quickly or twisting. To avoid this, be careful not to jerk your body too much. Your growing uterus will also affect the skin on your body. Your stomach may start to itch, and you may notice stretch marks developing on your tummy, your behind, and your thighs. For many women, stretch marks will even form on the thighs and bottom before they form on the stomach.
Other common discomforts that show up during the fifth month are heartburn and indigestion, increased perspiration, feet expanding, and some light cramping. The heartburn and indigestion are due to the increased size of the uterus and will come and go throughout the pregnancy. The perspiration is caused by the thyroid, which has been working and will continue working extra hard until the pregnancy is through. Like most pregnancy symptoms, the perspiration won't last. Your feet expanding is actually the result of increased fluid flowing throughout your body. Some of this fluid settles in the feet. Also, the ligaments in your entire body are relaxing, not just those around your uterus, so that, combined with the extra weight, can cause feet to stretch or expand a bit. Many women go up half a shoe size during pregnancy. If you experience some light cramping, don't worry about it. These cramps are just the beginning of Braxton hicks, which are light contractions that many women have from the fifth month on. If the cramping is painful or stops you from doing what you normally do, you'll want to see your caregiver. Hard cramps could be the sign of a complication.