Every physician attending a pregnant woman in the state of Washington during gestation shall, in the case of each woman so attended, take or cause to be taken a sample of blood of such woman at the time of first examination, and submit such sample to an approved laboratory for a standard serological test for syphilis. If the pregnant woman first presents herself for examination after the fifth month of gestation the physician or other attendant shall in addition to the above, advise and urge the patient to secure a medical examination and blood test before the fifth month of any subsequent pregnancies.