(1) For the purpose of RCW 48.21.244, 48.44.344, and 48.46.375, the following are standards of medical necessity for insurers, health care service contractors, and health maintenance organizations to use when authorizing requests or claims for prenatal screening and/or diagnosis without the requirement of a case-by-case determination and including preprocedure and postprocedure genetic counseling:

(a) Maternal serum marker screening for all pregnant women beginning prenatal care before the twentieth completed week of gestation.

(b) Maternal hepatitis B surface antigen (HBsAg) screening for all pregnant women during the first trimester of pregnancy and the last trimester of pregnancy if the woman is at high risk for hepatitis B infection.

(c) Information about Group B strep should be provided to all pregnant women, including the risk to the newborn, if the woman is identified through screening as potentially colonized with Group B strep. Screening is done through prenatal vaginorectal cultures, although specific clinical indicators may preclude screening. Pregnant women who are currently colonized with Group B strep, or who have unknown Group B strep status should receive intrapartum treatment in accordance with the current standard of practice in order to reduce risk to the newborn.

(d) Prenatal ultrasonography if one or more of the following criteria are met:

(i) A woman undergoing amniocentesis, chorionic villus sampling, or percutaneous umbilical cord blood sampling or fetal tissue biopsy;

(ii) The results of a maternal serum marker screening test indicate an increased risk to the fetus or pregnancy;

(iii) A woman or the biological father of the fetus has a personal or family history of a congenital abnormality detectable by prenatal ultrasound;

(iv) An increased risk of a congenital abnormality is present due to an environmental exposure including maternal exposure to alcohol; or

(v) A medical evaluation indicates the possibility of polyhydramnios or oligohydramnios.

(e) Amniocentesis if one or more of the following criteria are met:

(i) A woman is thirty-five years of age or older at the time of delivery;

(ii) A woman or the biologic father of the fetus has a previous child or fetus with a chromosomal abnormality or other prenatally diagnosable disorder;

(iii) A woman or the biologic father of the fetus has a family history that includes birth defects or developmental delays;

(iv) A woman or the biologic father of the fetus is a carrier of a chromosomal rearrangement;

(v) A woman and/or the biologic father of the fetus are carriers of, or affected with, a prenatally diagnosable inherited disorder;

(vi) The results of a maternal serum marker screening test indicate an increased risk to the pregnancy or fetus;

(vii) A woman has a documented history of three or more miscarriages of unknown cause when circumstances prevent parental chromosomal testing;

(viii) There is an ultrasound diagnosis of fetal anomaly;

(ix) A medical evaluation indicates an increased risk of fetal infection;

(x) Fetal blood studies are indicated for isoimmunization studies or therapy.

(f) Chorionic villus sampling with preprocedure and postprocedure genetic counseling if one or more of the following criteria are met:

(i) A woman is thirty-five years of age or older at the time of delivery;

(ii) A woman or the biologic father of the fetus has a previous child or fetus with a chromosomal abnormality or other prenatally diagnosable inherited disorder;

(iii) A woman or the biologic father of the fetus is a carrier of a chromosomal rearrangement;

(iv) A woman or the biologic father of the fetus is a carrier of, or affected with, a prenatally diagnosable inherited disorder;

(v) A woman has a documented history of three or more miscarriages of unknown cause when circumstances prevent parental chromosomal testing; or

(vi) Fetal genotyping is indicated to determine risks for isoimmunization.

(g) Fluorescent in-situ hybridization (FISH) if a medical evaluation indicates a rapid or specific submicroscopic chromosomal diagnosis is required to predict the prognosis for the fetus.

(2) The board recommends the following additional procedures for use by insurers, health service contractors, and health maintenance organizations in determining medical necessity on a case-by-case basis:

(a) Percutaneous umbilical cord blood sampling with preprocedure and postprocedure genetic counseling if one or more of the following criteria are met:

(i) A medical evaluation indicates rapid or specific submicroscopic chromosomal diagnosis or DNA diagnosis is required to predict prognosis for the fetus;

(ii) A medical evaluation indicates the possibility of a prenatally diagnosable fetal infection;

(iii) Fetal blood studies are medically indicated for isoimmunization studies or therapy;

(iv) Fetal blood is the only means to provide biochemical genetic diagnosis;

(v) Prenatal diagnosis of a hematological disorder is medically indicated.

(b) Prenatal tissue biopsy if the nature of the disorder in question indicates that fetal liver, skin, or other tissue biopsy is the only means to provide biochemical genetic diagnosis to protect the health of the mother or predict the prognosis of the fetus.