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First trimester weeks

Congrats! During the first trimester, you’re getting used to the idea of being pregnant.

Second trimester weeks

As you enter this second trimester, your body will settle down to pregnancy.

Third trimester weeks

You've reached the third and final trimester and will be heavily pregnant by now.

Week 10 of Pregnancy

No longer an embryo, your unborn baby enters a new phase.
This is your baby's last week as an embryo, next week she'll be known as a fetus. Her major organs are in place, although by no means in full working order. There's a long way to go yet and her body systems will continue to mature for the rest of pregnancy, and beyond. The most noticeable difference to your body will be in your breasts. You may well have gone up a cup size-or more.

9 Weeks, 2 Days

215 days to go...

human fetus at 9 weeks and 2 days

Your baby today

The baby now begins to bend her wrists. The natural position is for the limbs to be slightly bent at all joints, especially in the early stages. There is a more distinct neck area as the baby's head is now slightly lifted off the chest.
The muscular diaphragm that will eventually enable your baby to breathe-and hiccup-is developing now.

As your baby's lungs develop in the chest, there is nothing to separate them from the stomach, liver, and bowel in what will later become her abdominal cavity.

In adults, the chest is separated from the abdomen by the muscular diaphragm. When we breathe, the diaphragm moves downward and the ribs expand outward. This process allows air to enter the lungs.

Your baby's diaphragm forms from four in-folds of tissue. First seen at around this week of pregnancy, these folds gradually expand inward, fusing together and closing the space by the end of this week. In the center of the diaphragm there are openings for the esophagus to the stomach, main artery to the body-the aorta, and main vein returning blood from the lower body, the inferior vena cava. As your pregnancy progresses, muscle fibers gradually strengthen your baby's diaphragm, which later allows her to make breathing movements.

The nuchal translucency screening is a scan. It measures the width of the skin behind the baby's neck to assess if excess fluid has collected there-if a high level is found, it may indicate a greater risk of Down syndrome. Nuchal translucency is the most accurate way to screen for Down syndrome.

Red area shows the fluid under the skin at the back of the baby's neck.

Focus On... Twins

Twin tests

If you're expecting twins or more, blood-based screening tests for Down syndrome can mislead, since they rely on measuring the amounts of circulating AFP (alfa-fetoprotein) and other markers, which are present in much higher levels when there's more than one baby. That's why your best bet for screening is the nuchal translucency test from 11-14 weeks.

Time To Think About

Screening and diagnostic tests

It's useful to be aware of the screening tests and diagnostic tests that will be available in the weeks to come. Your doctor will talk through the pros and cons of having each test. Some abnormalities may be detected at the 18-22 week scan.

  • Screening tests: these tests identify the "risk factor" for a particular condition, but do not confirm that your baby definitely has a condition. For example, a screening test for Down syndrome may give your baby a risk factor of 1:200. This means that your baby has a 1 in 200 chance of being affected by Down syndrome, but it does not mean that he actually has the condition.
  • Diagnostic tests: if screening tests reveal your baby has a high risk factor for a chromosomal abnormality, you will be offered a diagnostic test, such as amniocentesis or chorionic villus sampling, which gives a definite result as to whether or not a condition is present.

9 Weeks, 2 Days

215 days to go...

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