Pregnancy Test:
Why Pregnancy Test ?
CLINICAL INFORMATION
Clinical assessment (antenatal care) and abdominal or vaginal ultrasound (obstetric ultrasonography the gestational sac – intrauterine fluid collection in 4 to 5 weeks gestation and other findings can be made such as yolk sac, fetal pole and/or multiple gestations etc) scans for early visualization of pregnancy remains significant during pregnancy apart from other lab tests. Routine pregnancy tests such as progesterone (hormone assays) are generally performed. Other special tests such as HCG, double marker test, triple marker test (AFP, HCG and Estriol), quadruple tests (preferably performed during the second trimester – estimates the levels of AFP, HCG, Estriol and Inhibin A) etc, are performed in suspected abnormal cases during pregnancy. Beta (β) HCG test:Human chorionic gonadotropin (HCG) is a pregnancy hormone (embryonic hormone), synthesized during pregnancy by the developing placenta that nourishes the fertilized egg attached to the uterine wall. HCG interacts with LHCG receptor of the ovary and promotes the maintenance of the corpus luteum for the maternal recognition of pregnancy. HCG promotes progesterone production by corpus luteal cells, promotes angiogenesis in uterine vasculature etc. HCG can be detected in blood specimens of pregnant women within a span of 11 days of conception (suspected if there is a missed menstrual period). The levels of HCG continue to double every 48 to 72 hours, and their levels peak around 8 to 11 weeks after conception. Beta (β) HCG tests are performed in blood and/or a urine specimen to measure quantitative amounts of HCG in the blood to confirm a pregnancy. It can also help in certain conditions such as ectopic pregnancies, along with progesterone tests. HCG test is usually performed to confirm pregnancy, determine the approximate age of the fetus, diagnosis of gestational trophoblastic disease (GTD) abnormal pregnancies such as ectopic pregnancy, hydatidiform mole or also called as molar pregnancy (anembryonic pregnancy - abnormal mass forms inside uterus instead of the normal embryo), teratomas etc, multiple pregnancy such as twins or triplets, potential miscarriage and prenatal screening for Down’s syndrome etc, cancers (since HCG levels are higher in some kind of tumors) such as lung cancer, breast cancer, ovarian cancer, cancer of the uterus, choriocarcinoma and non-cancerous conditions such as cirrhosis(liver), ulcers of the stomach and inflammatory bowel disease, In male population higher levels of HCG are present in marijuana smokers, high levels of HCG is indicated in testicular cancers (germ cell tumours) etc. Certain conditions like fertility drugs such as profuse, Pregnyl and/or pergonal etc and/or antibodies if present against HCG molecule, and/or women with severe hormonal change due to any disease/disorder can also give false-positive results (i.e women is non-pregnant yet can get positive for a pregnancy test) for HCG test. HCG levels are useful in monitoring during the prognosis of gestational trophoblastic diseases and/or HCG secreting tumours. Other associated tests are ultrasound around six weeks etc. Double Marker Test: Beta HCG is secreted by the placenta and its function in early pregnancy is to maintain the corpus luteum (helps in sustaining the levels of progesterone). PAPP-A (Pregnancy Associated Plasma Protein -A) is secreted by the placenta and its levels are elevated as the pregnancy progresses. The probability of abnormal birth defects in pregnancies can rarely occur among normal pregnancies and such possibilities are higher with an increase in the risk of certain factors involved in it, such as inherited hereditary diseases (congenital disabilities, inborn errors of metabolism etc) that run in certain families etc. Thus, these birth defects in pregnancies can range in severity ranging from anatomical abnormalities (anomalies) to serious mental retardation. Therefore genetic screening can help in the prevention of such abnormal (developing fetus) pregnancies and can help abort (during initial trimesters of pregnancy – most likely from 9 to 13 weeks of gestation) delivering such defective children (who would otherwise suffer for the rest of their lives along with their parents). A double marker test and NT Scan (Nuchal Translucency test confirms the diagnosis of genetic abnormalities) are performed during the first trimester. Even though their test is not always mandatory in all pregnancies. However if the woman is pregnant over 35 years and/or pregnant for the first time, then this test helps in the assessment i.e if the unborn baby is at risk of chromosomal abnormalities (chromosomal malformation) associated with (neurological defects) mental disorders such as Down’s syndrome, Trisomy 18, Edward’s syndrome, mental retardation and/or severe birth defects. This test is done with an ultrasound and blood sample specimen for two tests. Thus this Double Marker Test (also called as Maternal Serum Screening Test/Dual Marker Test) looks for two markers namely – free beta HCG and PAPP-A. High levels of beta HCG and/or low levels of PAPP-A are indicative of chromosomal abnormalities in a developing fetus. Hence a double marker test is a screening test in pregnancy that is a useful tool to determine the healthy development of a fetus. Pregnancy tests can also be used to screen other non-pregnant mimicking pathological (abnormal) conditions such as choriocarcinoma, germ cell tumours, gestational trophoblastic diseases (GTD), gestational trophoblastic neoplasms, enterocystoplasties, heterophile antibodies, IgA deficiencies, miscarriage, spontaneous abortion, pregnancy loss, ectopic pregnancy etc, and hence this test serves in the differential diagnosis. Meanwhile, there are also more additional tests available such as the Triple Marker Test (AFP, HCG and Estriol), Quadruple Tests (preferably performed during the second trimester – estimates the levels of AFP, HCG, Estriol and Inhibin A) etc. Additional tests (first, second and third-trimester tests) include Alpha-Fetoprotein (AFP), Amniocentesis, chorionic villus sampling (PCR tests), karyotyping, free cell fetal DNA test (shotgun sequencing), methylated DNA immuno-precipitation (with tilling array), microRNA and/or total RNA sequencing, FISH test, prenatal tests for abnormal pregnancies such as down’s syndrome, trisomy - 13, trisomy - 18, cystic fibrosis, Tay-Sachs disease, spina bifida, muscular dystrophy, fragile X syndrome, aneuploidies (nuchal translucency scan and MLPA tests), anatomical defects such as hydrocephalus, anencephaly etc.
General Instructions:
Sample Requirement: Specimen - Urine Sample. Test Preparation: None.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
