Pregnancy Week 13

The second trimester officially starts from the 13^th week of pregnancy. The fetus is fully developed, and the chances of miscarriage decrease as the weeks progress. This is also the time for prenatal screening for conditions such as down syndrome and other genetic disorders.

What happens during the 13^th week of pregnancy? 

By the 13^th week, women enter the second trimester of pregnancy, and the fetus is about 7.5 cm long and weighs close to 30g. They also move inside the uterus extending the arms and legs, and also suck the thumb while making a fist. Several of the major organs are also functions, such as the liver and pancreas. The kidneys function to produce urine that gets mixed with the amniotic fluid. The fetus also practices swallowing and breathing. In the face, soft hair is beginning to grow to form the eyebrows. The genitalia of the fetus also start developing at this point but is too small to be detected in a pregnancy ultrasound scan.

Morning sickness and other pregnancy symptoms start to ease by the start of the second trimester. Many women also experience the ligaments in the abdomen and groin stretching as the 13th-week pregnancy belly begins to expand. Tenderness in the breasts persists as it gets bigger and stretches the skin making the veins appear more prominently. Women might continue feeling tired or having food cravings and a versions. Now that the uterus is larger, it has also risen higher into the abdominal cavity from the pelvis, relieving pressure on the bladder. However, it might increase other gastric symptoms such as heart burns, bloating and constipation.

Prenatal screening 

From the end of the first trimester, a range of tests can be performed to assess the development of the fetus and screen for any health conditions. Prenatal screening can show if the fetus has a high risk of a particular disorder, which can then be confirmed by diagnostic tests. Some of the prenatal screening tests include:

• Tests for chromosomal conditions such as down syndrome and patau syndrome
• Test for neural tube defects (NTD) such as spina bifida or anencephaly
• Birth defects- kidney condition or congenital heart defects

The pregnancy screening for chromosomal abnormalities is done using ultrasound called a nuchal translucency scan to measure the thickness of the fluid at the back of the fetus’s neck. It can assess the risk of chromosomal abnormalities such as trisomy 21 (down syndrome), trisomy 13 (Patau syndrome) and trisomy 18 (Edwards syndrome). The pregnancy screening for down syndrome is typically done anywhere from week 11 to week 14, along with a dating scan or later at the start of the second trimester.

Wrapping up

Week 13 is the start of pregnancy second trimester, with the fetus fully developed, resembling a human being. The pregnancy symptoms such as morning sickness and tiredness are usually low, and women enter a more relaxed phase of the pregnancy. This is also the time for a range of prenatal screening tests to determine the risks of birth defects in the fetus.