Appendix 1
The Chronological Development of The Unborn Child

 

Twelfth Week

 

Timing

Source
The face has all the human characteristics.
12th week Sadler, p 116
Movements begin, but are usually not felt by the mother. 12th week after fertilization Sadler, p 116
Jaw openings were observed in 12 of 12 fetuses studied with a median rate of about 30 per hour. 12th week after conception de Vries (1985), p 114
The neck is well-defined. 12th week after fertilization Moore, p 109; Williams, p 155
The sex can be established by ultrasonic measurement of the external genitalia. 12th week after fertilization Sadler, p 113
The sex can be determined from external examination. 12th week after fertilization Moore, p 109
The fetus responds to stimulation of the skin. 12th week after fertilization England, p 206
Red blood cells are forming in the spleen. End of 12th week after fertilization Moore, p 112
Primary ossification centers appear in the skeleton, especially in the skull and long bones. End of 12th week after fertilization Moore, p 110, Sadler, p 113
Hair grows on the eyebrows and the upper lip. End of 12th week after fertilization Moore, p 517
Stroking the lips causes the fetus to suck and stroking the eyelids results in a reflux response. End of 12th week after fertilization Moore, 4th edition, p 91
The sex is clearly distinguishable. End of 12th week after fertilization Williams, p 154
The upper limbs have almost reached their final relative lengths and are a bit better developed than the lower limbs. End of the 12th week after fertilization Moore, p 111
Respiration is evident. 12th - 14th weeks after fertilization Williams, p 169
Swallowing is evident. 12th - 14th weeks after fertilization Williams, p 169
Palm creases appear. 3rd month Rugh, p 217
The spinal cord extends the entire length of the embryo. 3rd month of development Sadler, p 422
Taste buds are evident. 3rd lunar month Williams, p 169
The first hairs appear in the region of the eyebrows and upper lip. End of 3rd month Sadler, p 407
Reflex activity can be evoked in aborted fetuses, indicating muscular activity. End of 3rd month after fertilization Sadler, p 114
The penile urethra is forming. End of 3rd month Sadler, 7th edition p 298


 


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