Top Posters
Since Sunday
r
4
L
4
3
d
3
M
3
l
3
V
3
s
3
d
3
a
3
g
3
j
3
Home Gallery General Biology
Explore Categories
  
SlideshowReport

Maternal Changes During Pregnancy
Download Without Watermark With Free Membership
Description
Noninvasive prenatal tests may also be performed, but they are currently not as informative as amniocentesis and chorionic villus sampling.
The maternal alpha-fetoprotein (AFP) test requires a blood sample from the mother. It is used to detect AFP (a protein produced by the fetus at its highest levels between weeks 12-15) after the 16th week of pregnancy when levels go to zero. High levels at this point indicate a neural tube defect.

During the first 3 to 4 months of pregnancy, the corpus luteum secretes progesterone and estrogens in low levels.
From the 3rd month to the end of the pregnancy, the placenta produces high levels of these hormones.
The chorion secretes human chorionic gonadotropin (hCG) to stimulate the corpus luteum to produce estrogens and progesterone to inhibit menstruation until the placenta takes over.
Related Images
 1747
 150
 358
 13692
 908
 701
 340
 425
 11420
 91
Add Comment
Explore
Post your homework questions and get free online help from our incredible volunteers
  1474 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Your Opinion
What percentage of nature vs. nurture dictates human intelligence?
Votes: 436
Previous poll results: Should Ph.D.'s be addressed as doctors?