[an error occurred while processing this directive]

Prenatal Tests


Prenatal TestWhy the test?TimeNarmal ValueFollow-up in case of preblem
Blood type and Rh factorPossibility for incompatibility beween mother's and baby's bloodPreconception of first visitAny result is normal, but if mother is Rh negative, possibility for incompatibility existsTest for antibodies in blood; test baby's father's blood; if baby's father has Rh positive blood or is unavailable for testing, repeat antibody testing later in pregnancy; treat with RhoGAM at 26-28 weeks and postpartum
Chlamydial culture or screening testChlamydia infection (common STD)Preconception and/or first prenatal visitNegativeTreat with antibiotic; test and treat partner; retest for cure
Cystic fibrosisCarrier for cystic fibrosis; most common among CaucasiansPreconception or first prenatal visitNegativeTest partner; genetic counseling
Diabetes Screen (GCT)Possible diabetes26-28 weeks of pregnancy; earliet in women at risk for diabetesUsually <135 or < 140Retest with 3-hour GTT for definite diagnosis
Gonococcal culture or screening testGonorrhea infectionPreconception and/or first prenatal visit; may be repeated at 36th weekNegativeTreat with antibiotic; test and treat partner; retest for cure
Hemoglobin electrophoresisSickle-cell anemia or traitPreconception or first visitHemoglobin AATest partner; if partner has disease or is carrier, genetic counseling to discuss risk of infant's have disease; prenatal diagnosis of fetus available
Hemoglobin or HematocritLow levels of this oxygen carrying chemical in the bolld, of anemiaPreconception of first visit; repeated in 3rd trimesterHemoglobin >= 12 Hematocrit >= 36Treat with diet and iron; retest after treatment
Hepatitis BHepatitis B infection or immunityPreconception or first prenatal visitNegative antigen; may show positive antibody, indicating previous infection and possible immunity. If antigen is present, you may have the disease or be a carrier of the diseaseIf infectious, retest later in pregnancy; supportive care; treat baby
HIV testingPresence of antibodies to virus causing AIDSPreconception of rist visit; may be offered again at 36th week.NegativeSee provider with experience caring for pregnant women with HIV; have sounseling regarding treatmen options to reduce possibility of transmission to fetus.
Material serum aplhafetoprotein (AFP)Possibility of some types of genetic defects (open neural tube defects)14th to 18th week of pregnancyLevels appropriate for timing in pregnancySonogram to check dating of pregnancy; repeat test; if level remains abnormal, genetic counseling and aminocentesis
Pap smearCervical cancer or precancerous conditions, other cervical and/or vaginal problems such as infectionsPreconception or first prenatal visitNegativeRepeat Pap smear after 3 months, further testing, or treatment, depending on findings
Random blood glucosePossible diabetesFirst prenata visit for women at risk for diabetesUsually < 120Retest with more specific blood test for diabetes
Rubella titerGerman measles; shows susceptibility, immunity, or possible infectionPreconception of first visit; if susceptible, may need to repeat test if exposure or symptoms occurNegative test of low titer indicates suceptibility; high titer indicates possible infection; moderate titer, immunityIf susceptibility discovered preconceptionally, consider vaccination and avoid pregnancy for 28 days; if pregnant, avoid exposure and have vaccine after pregnancy. If possible infection, retest and confirm; if pregnancy and infected, seek genetic counseling to discuss risks to fetus.
Serologic testing for syphilis (RPR or VDRL)SyphilisPreconception and/or first visit; may be repeated in 3rd> trimester in woemen at risk of STDNegativeTreat with penicillin or other antibiotic, unless previously treated, then retest for reinfection; test and treat partner; retest for cure
Serologic testing for toxoplasmosisToxoplasmosis infection for immunityPreconception or first visitNegative or low levels indicate susceptibility; moderate levels show infection with immunity; high levels may indicate current infectionRetest may be necessary to ascertain infection; if mother infected, treat with antibiotic to prevent fetal transmission; if susceptible avoid cat feces, rare or raw meat
Tay-SachsCarrier of Tay-Sachs diseasePreconception or first visit in persons of Ashkenazi Jewish backgroundNegative CarrierTest partner; genetic counseling if both partners are carriers; prenatal diagnosis of fetus available
Tuberculosis skin test (Tine or PPD)Exposure to tuberculosis or possible past or present infectionPreconception or first prenatal visit of folowing known exposureNegativeChest X-ray after 20 weeks of pregnancy; possible treatment
Urine culture and urinalysisUrinary tract infectionFirst prenatal visit; may be repeated if symptoms occur later in pregnancy or if at riskNegativeTreat with antibiotic; self-help preventive and curative measures; retest for cure
Urine dipstickProtein and suger in urine, which may indicater kidney problems, speeclampsia, or possible diabetesPreconception and first visit; repeat at all subsequent visitsNegativeMay necessitate further testing
[an error occurred while processing this directive]