Editing Triple test (section)

===Quadruple test===
A test of levels of dimeric [[inhibin]] A (DIA) is sometimes added to the other three tests, under the name "quadruple test."<ref name="pmid16700087">{{cite journal |vauthors=Wald NJ, Morris JK, Ibison J, Wu T, George LM |title=Screening in early pregnancy for pre-eclampsia using Down syndrome quadruple test markers |journal=Prenat. Diagn. |volume=26 |issue=6 |pages=559–64 |year=2006 |pmid=16700087 |doi=10.1002/pd.1459|s2cid=1751873 }}</ref> Other names used include "quad test", "quad screen", or "tetra screen."  Inhibin A will be found high in cases of trisomy 21 and unchanged in cases of trisomy 18.<ref name="pmid11494294">{{cite journal |vauthors=Spencer K, Liao AW, Ong CY, Flack NJ, Nicolaides KH |title=Maternal serum activin A and inhibin A in trisomy 18 pregnancies at 10-14 weeks |journal=Prenat Diagn. |volume=21 |issue=7 |pages=571–574 |year=2001 |pmid=11494294 |doi=10.1002/pd.125|s2cid=32154357 }}</ref>

{| class="wikitable"
| '''[[Inhibin]] A''' || '''Associated conditions''' 
 |- 
 | High || [[Trisomy 21]] (Down syndrome)
 |- 
 | Unchanged || [[Trisomy 18]] (Edwards syndrome)
 |-
 | Variable || [[Trisomy 13]] (Patau syndrome)
|}