You are almost 5 months through your pregnancy (4.5 months since conception) and your life is changing more and more everyday in a wonderful way. You are probably already in maternity clothes with people wishing you the best, and some even wanting to touch your belly to feel your baby, wherever you go. The second trimester is the best time of being pregnant with a relatively higher energy level and fewer unpleasant symptoms.
Fetal development this week
Internal organ development
With all the major organ developed and in place, your baby is now poised to grow in size and gain weight. He is swallowing larger amounts of amniotic fluid this week as the digestive system gets a better workout . The meconium production (the dark sticky substance that will be your baby’s first bowel movement) continues from the previous weeks as a result of the digestive function .
Sensory organ development
The small bones in the inner ear are now properly developed while the characteristic external structures of the nose begin to form . The eyelids that have been fused shut for the past weeks may begin to open this week in some babies . Your baby also has working taste buds at this stage .
Vernix caseosa, the waxy white substance produced by the fetal sebaceous glands  to protect him from the amniotic fluid, is now covering your baby’s entire body . The transparent skin also starts forming fat layers underneath it, making him look less skinny .
He also starts growing scalp hair this week that will be present at birth. But, this hair will fall out within a couple of weeks after your baby is born before the lighter, permanent hair can begin to grow .
How big is your baby this week?
He is now almost as big as a banana, weighing around 10.2 oz (289.17 gm) . His crown to rump length is about 6.5 inches (16.5 cm) while he is approximately 10 inches (25.4 cm) long from head to heel . The fetus’ legs remain curled up in front of his body until the 19th week, making it impossible to measure his length from head to feet. However, they begin to straighten up from the 20th week onward, enabling your health care provider to measure his actual height.
Pregnancy week 20: Your belly and body changes
Your body is undergoing many changes apart from the obvious – the growing baby bump; and you must also feel these changes with every passing day. Your changing center of gravity due to the growing belly and the considerable weight gain are the most evident ones .
Your uterus is now three times as big as its original size with the top of it now being at the same level with your bellybutton . It will be growing about 1 cm every week until delivery . Your baby is growing inside the uterus as those kicks and punches start to feel more like real fetal movements rather than the quickening in the earlier weeks.
20 weeks pregnant ultrasound scan
You will have your mid-pregnancy ultrasound around this week (if it has not been done last week) as it is usually performed between the 18th and 20th weeks . Known as an anomaly scan, it is performed for evaluating the fetal growth, screening for certain birth defects (like neural tube defects and Down’s syndrome) and confirming your due date . The ultrasound also allows your doctor to observe the baby’s limbs, fingers and toes for any abnormality, while assessing the umbilical cord, placenta and amniotic fluid to make sure that the baby is getting everything necessary for proper growth . You can also see the straightening spine  in addition to finding out the gender of your baby .
Twin pregnancy week 20 ultrasound
In a twin pregnancy, two babies are generally scanned separately to screen for any physical or other abnormalities. The appearance and size of the two babies is evaluated as well to make sure they both have the same growth rate .
Signs and symptoms at pregnancy week 20
- Round ligament pain 
- Joint, hip, rib and back pain
- Leg cramps
- Indigestion and heartburn 
- Gas and flatulence
- Feeling out of breath 
- Swelling of the hands and feet
- Swollen and/or bleeding gums
- Itchy skin around the belly, back and chest 
- Sleep disturbances or insomnia
- Emotional changes and mood swings
- Occasional headaches and dizziness 
- The bellybutton protruding outward with or without a little pain and soreness around the area 
- Increased vaginal discharge 
When to call the doctor
- Constant headache or migraine along with vision changes, heart palpitations, sudden swelling (of the hands and feet) and upper abdominal pain (might indicate preeclampsia) 
- Severe itching without any skin rash (might indicate a rare liver disorder named obstetric cholestasis) 
- Experiencing symptoms like stomach cramps, severe nausea, lower back pain, increasing pressure in the pelvic region, vaginal bleeding or spotting  or any kind of change in discharge (might indicate an open cervix  or a possible miscarriage)
- Burning sensation during urination  along with considerable lower back pain and yellowish jellylike or white thick discharge (might indicate an infectious condition like yeast infection)
- Extreme fatigue accompanied by excessive thirst, dry mouth, increased urination and vision problems (might indicate gestational diabetes) 
Tips for a healthy pregnancy and baby
- Making sure to follow a proper dental health routine (brushing and flossing regularly) and going for dental checkups to avoid conditions like gingivitis in pregnancy 
- Avoiding any kind of x-ray unless absolutely necessary as it might hurt your baby 
- Practicing sleeping on your side (preferably left side) as sleeping on your stomach is probably not comfortable any more (due to the growing belly) and sleeping on your back may reduce blood flow to the fetus by putting pressure on a major nerve 
- Following a diet consisting of foods rich in iron (spinach, dried beans, dry fruits, lean red meat), as it is necessary for hemoglobin production in your baby. Adequate iron intake also lowers your chances of developing anemia .
- Making healthy food choices to avoid excessive weight gain, especially in case of twin and overweight pregnancies
- Doing prenatal yoga or some light exercise regularly to keep the abdominal and pelvic muscles flexible
- http://www.webmd.com/baby/features/sleep-soundly-during-pregnancy [/ref]