Items in AFP with MESH term: Chorionic Gonadotropin
ABSTRACT: Down syndrome (trisomy 21) is the most commonly recognized genetic cause of mental retardation. The risk of trisomy 21 is directly related to maternal age. All forms of prenatal testing for Down syndrome must be voluntary. A nondirective approach should be used when presenting patients with options for prenatal screening and diagnostic testing. Patients who will be 35 years or older on their due date should be offered chorionic villus sampling or second-trimester amniocentesis. Women younger than 35 years should be offered maternal serum screening at 16 to 18 weeks of gestation. The maternal serum markers used to screen for trisomy 21 are alpha-fetoprotein, unconjugated estriol and human chorionic gonadotropin. The use of ultrasound to estimate gestational age improves the sensitivity and specificity of maternal serum screening.
ABSTRACT: According to the American College of Obstetricians and Gynecologists, it has become standard in prenatal care to offer screening tests for neural tube defects and genetic abnormalities. There have been some changes in the recommended method of prenatal screening over the past few years, and research to improve detection rates with better combinations of maternal serum analytes is ongoing. The issues facing physicians are the sensitivity and specificity of multiple serum analyte combinations. The current maternal serum analytes in use in most areas are alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG) and unconjugated estriol. Measurement of AFP alone can detect the vast majority of neural tube defects and a small portion of trisomy 21-affected pregnancies in patients of all ages. Adding hCG and unconjugated estriol to this screen increases the rate of detection of trisomies 21 and 18. Counseling patients about the risks and benefits of such screening is important to provide a balanced discussion of screening issues.
First Trimester Bleeding - Article
ABSTRACT: Vaginal bleeding in the first trimester occurs in about one fourth of pregnancies. About one half of those who bleed will miscarry. Guarded reassurance and watchful waiting are appropriate if fetal heart sounds are detected, if the patient is medically stable, and if there is no adnexal mass or clinical sign of intraperitoneal bleeding. Discriminatory criteria using transvaginal ultrasonography and beta subunit of human chorionic gonadotropin testing aid in distinguishing among the many conditions of first trimester bleeding. Possible causes of bleeding include subchorionic hemorrhage, embryonic demise, anembryonic pregnancy, incomplete abortion, ectopic pregnancy, and gestational trophoblastic disease. When beta subunit of human chorionic gonadotropin reaches levels of 1,500 to 2,000 mIU per mL (1,500 to 2,000 IU per L), a normal pregnancy should exhibit a gestational sac by transvaginal ultrasonography. When the gestational sac is greater than 10 mm in diameter, a yolk sac must be present. A live embryo must exhibit cardiac activity when the crown-rump length is greater than 5 mm. In a normal pregnancy, beta subunit of human chorionic gonadotropin levels increase by 80 percent every 48 hours. The absence of any normal discriminatory findings is consistent with early pregnancy failure, but does not distinguish between ectopic pregnancy and failed intrauterine pregnancy. The presence of an adnexal mass or free pelvic fluid represents ectopic pregnancy until proven otherwise. Medical management with misoprostol is highly effective for early intrauterine pregnancy failure with the exception of gestational trophoblastic disease, which must be surgically evacuated. Expectant treatment is effective for many patients with incomplete abortion. Medical management with methotrexate is highly effective for properly selected patients with ectopic pregnancy. Follow-up after early pregnancy loss should include attention to future pregnancy planning, contraception, and psychological aspects of care.