Your midwife will offer to take a blood sample about now. This is sent to a lab and tested for serum markers, which are proteins that may be present in your blood. The presence of these markers may indicate whether your baby is at risk of Down’s syndrome. Your midwife might also recommend a test called chorionic villus sampling (CVS), if you’re at particularly high risk of having a baby with a serious inherited condition such as cystic fibrosis.
All the vital organs such as the kidneys, liver and lungs, are now in place and begin to grow and develop rapidly. Up to this point, an additional sac inside the amniotic fluid has been providing red blood cells, but now the baby’s liver is producing them for itself and the yolk disappears.
Week 10 is also when you’re likely to have the highest levels of the pregnancy hormone HCG in your blood, so sickness and other symptoms may be particularly severe.
You can help prevent or reduce sickness by eating small but frequent low-fat meals, and trying to get plenty of rest and fluids. It might help to keep a plain biscuit or cracker by your bed, to nibble before getting out of bed or if you wake feeling sick in the night. If you have very severe sickness, talk to your doctor or midwife about treatment.
Your waistline is slowly disappearing! Remember to measure your waist and belly now, if only to compare for fun as the pregnancy progresses.
The baby now enters it’s fetal period. The average size of the foetus now is approximately 27-35 mm crown to rump length and weighing about 4 grams. Toes have formed. The eyes are largely open, but the eyelids are still fused. External genitalia is beginning to differentiate. External ears are completely formed, as well as the upper lip. The tail should have disappeared by now.