Cloherty and stark’s manual of neonatal care 8th Edition PDF Download
Cloherty and stark’s manual of neonatal care 8th Edition PDF free download GESTATIONAL AGE ASSESSMENT is important to both the obstetrician and pediatrician and must be made with a reasonable degree of precision. Elective obstetric interventions such as chorionic villus sampling (CVS) and amniocentesis must be timed appropriately. When premature delivery is inevitable, gestational age is important with regard to prognosis, the management of labor and delivery, and the initial neonatal treatment plan.
A. The clinical estimate of gestational age is usually made on the basis of the first day of the last menstrual period (LMP). Accompanied by physical examination, auscultation of fetal heart sounds and maternal perception of fetal movement can also be helpful.
Cloherty and stark’s manual of neonatal care 8th Edition PDF free download B. Ultrasound is the most accurate method for estimating gestational age. During the first trimester, fetal crown- rump length (CRL) can be an accurate predictor of gestational age. At <8 weeks and 6 days if the CRL and the LMP are >5 days different, the ultrasound is the best estimate for gestational age. From 9 0/7 to 15 6/7 weeks, CRL estimation of gestational age is expected to be within 7 days of the true gestational age. After 14 weeks,
measurements of the biparietal diameter (BPD), the head circumference (HC), abdominal circumference (AC), and the fetal femur length best estimate gestational age. Strict criteria for measuring the crosssectional images through the fetal head ensure accuracy. Nonetheless, owing to normal biologic variability, the accuracy of
gestational age estimated by biometry decreases with increasing gestational age.
Cloherty and stark’s manual of neonatal care 8th Edition PDF free download For measurements made at 16 to 21 6/7 weeks of gestation, the variation is up to 10 days; at 22 to 27 6/7 weeks, the variation is up to 14 days; and at 28 weeks and beyond, the variation can be up to 21 days. II. PRENATAL DIAGNOSIS OF FETAL DISEASE continues to improve. The genetic or developmental basis for many disorders is emerging, along with increased test accuracy. Two types of tests are available: screening tests and diagnostic procedures. Screening tests, such as a sample of the mother’s blood or an ultrasound, are noninvasive but relatively nonspecific. A positive screening test, concerning family history, or an ultrasonic examination that suggests anomalies or aneuploidy may lead patient and physician to consider a diagnostic procedure. Diagnostic procedures, which necessitate obtaining a sample of fetal material, pose a small risk to
both mother and fetus but can confirm or rule out the disorder in question.
A. Screening by maternal serum analysis during pregnancy individualizes a woman’s risk of carrying a fetus with a neural tube defect (NTD) or an aneuploidy such as trisomy 21 (Down syndrome) or trisomy 18 (Edward syndrome).