First-trimester screening for Down’s syndrome in in vitro fertilization pregnancies Marko Niemimaa, M.D., Seppo Heinonen, M.D., Maija Seppälä, Ph.D., Marita Hippeläinen, M.D., Hannu Martikainen, M.D., Markku Ryynänen, M.D. Fertility and Sterility Volume 76, Issue 6, Pages 1282-1283 (December 2001) DOI: 10.1016/S0015-0282(01)02871-0
FIGURE 1 Multiples of medians for maternal serum levels of free β-hCG values in natural and IVF pregnancies. Niemimaa. Down’s syndrome screening in IVF pregnancies. Fertil Steril 2001. Fertility and Sterility 2001 76, 1282-1283DOI: (10.1016/S0015-0282(01)02871-0)