During pregnancy week 6, the gestational age is 5 weeks which means it would be between 36 and 42 days since the last menstruation. The embryonic age would be 3 weeks or between 22 and 28 days from date of fertilisation. At pregnancy week 6, the embryo begins to curve into a C shape and measures approximately 1/8 inch or 4 mm in length, though this can vary between 2 and 5 mm! The grooves that form the face and neck structures become evident – these are called branchial arches. Rudimentary ears – called the otic pits start to form and the heart develops further by bulging and beats with a rhythm, between 100 and 140 beats per minute. This may be picked up only on the ultrasound machine at this stage, but will become more audible within the next few weeks. Arm buds make an appearance along with a tail and the rudiments of the mouth form with the membrane rupturing at that point. Pregnancy week 6 will be indicated by the neural tube closing and the primordial lungs beginning to form, together with the future liver, gall bladder and pancreas. The urinary passage and the rectal passage separate, ureteric buds appear along with the spleen. Anterior and posterior horns in the spinal chord can now be differentiated quite clearly during pregnancy week 6. Dark spots form where the eyes and nose will eventually take shape.

During pregnancy week 6 the mother may show some weight gain – between 1 to 5 pounds, though there are many women who experience weight loss during the first trimester due to ‘morning sickness’ and the nausea associated with it tends to put off the appetite. The resultant weight loss in a woman with body mass within the ideal limits should not be allowed to increase substantially as it may cause complications later on in the pregnancy. Severe forms of morning sickness may require hospitalisation. Pregnancy week 6 usually results in a thicker waist and if there is any spotting (of blood) consulting the doctor or healthcare professional is advisable as it may indicate concerns. The breasts become tender and the uterus starts growing in size – to that of a plum. Diet during this period should be normal, though a few additional calories are fine. However, the notion that the mother needs to eat for two persons throughout the pregnancy is incorrect; an additional 300 calories per day during the second trimester is good enough and this is does not mean eating a lot – as one bagel contains about the 300 calories. Once the morning sickness wears off, appetite and even hunger replace it – to prevent overeating, several small meals throughout the day is advisable and they should have high fibre content. Fibre makes the person feel full for a longer period and also prevents a common side effect of pregnancy from becoming severe – constipation! A healthy diet including lots of fruits and nuts as well as yoghurt should be the norm during pregnancy week 6.

Copyright Leonard Greenhall (c) 2009