Amniocentesis and CVS PowerPoint Presentation

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ASSESSMENT OF Fetal Well-being Lectures 3

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Assessment of fetal well-being The major expected outcome is the detection of potential fetal compromise Used before intrauterine asphyxia of the fetus and health care provider can take measures to prevent or minimize adverse perinatal outcomes First- and second-trimester antepartal assessment is directed primarily at the diagnosis of fetal anomalies. The goal of third-trimester testing is to determine whether the intrauterine environment continues to be supportive to the fetus.

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Daily Fetal Movement Counts

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Daily Fetal Movement Counts Kick Counts Assessment of fetal activity by the mother Non-invasive, inexpensive, simple to understand, and does not interfere with routine at home once a day, roughly at the same time every day in a comfortable sitting or lying position when baby is usually active (after meals, after activity, and in the evening). Since healthy babies have sleep cycles, baby may not kick, or kick less than usual, or have less than 10 kicks in 2 hours. If so, wake up the baby by drinking fluid or by walking for 5 minutes. Repeat the kick count.

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Daily Fetal Movement Counts Kick Counts No less than3 movements in 30 minutes Most healthy babies should take less than 2 hours for 10 kicks. not moved 10 times in 2 hours or the baby has sustained significant changes. Fetal alarm signal if no movement in 12 hours The evaluation may include: Ultrasound - taking pictures from sound waves to evaluate the growth of the baby, amniotic fluid quantity, placenta, blood flow pattern etc. Non stress test (NST) -Baby's heart rate monitoring in response to its own movements Biophysical profile (BPP) -using an ultrasound exam with a non stress test (NST) to evaluate baby's heart rate, breathing, body movement, muscle tone, and amniotic fluid quantity Contraction stress test (CST) -Baby's heart rate monitoring in response to uterine contractions

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OBSTETRICULTRASOUND

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7 Ultrasound in obstetrics can provide good information about the fetus and its environment With ultrasound, can be determined an early intervention or conservative management in pregnancy Latest developments in ultrasound examination is a transvaginal ultrasound discovery - the observation of "FLOW DOPLLER" and the most sophisticated ultrasound 3 D and 4D which has a high ability to determine fetal condition

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Ultrasonography Indications for use Fetal heart rate activity Gestational age Fetal growth Fetal anatomy Fetal genetic disorders and physical anomalies Placental position and function visual assistance to other invasive tests Fetal well-being

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Ultrasonography Abdominal After 1 trimester Full blader Vaginal 1 trimester Early diagnostic of uterine pregnancy Empty blader Obese woman

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Ultrasonography An important and safe technique in antepartum fetal surveillance Levels of ultrasonography: Standard examination Used for specific indications, i.e., fetal viability, fetal presentation, gestational age, locate the placenta, fetal anatomy and malformation Specialized or targeted examination Suspicion of an abnormal fetus (abnormal finding on clinical examination, poly- or oligohydramnionios, elevated AFP)

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Ultrasonography: Indication for use 1 trimester Number, size, location of gestational sac Fetal cardiac and body movement Uterine abnormalities (bicornuate uterus, uterine fibroid, IUD) or adnexal masses Duration of pregnancy (crown-rump length) Visualization during chorionic villus sampling

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12 Ultrasonography: Indication for use ( 2nd and 3rd trimester ) Fetal viability, number and presentation, Establishment of fetal age and growth by fetal biometry including: BPD ~ biparietal diameter FL ~ femur length AC ~ Abdominal circumference Biophysical profile Evaluation of fetal anatomic structures: Cerebral lateral ventricles Spine Four chamber view of the heart Stomach-bowel, abdominal wall at the area of the umbilical cord insertion Bladder and kidney Limbs and umbilical cord Amount of amniotic fluid Placental localization and maturity Evaluation of the uterine, and adnexae for abnormalities and masses Cervical length Visual assistance to invasive tests

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Fetal heart activity 6-7 weeks by echo scaner 10-12 weeks by Doopler Fetal viability Fetal cardiac activity Fetal movement Breathing movement

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Gestational age Gestational sac dimensions (about 8 weeks) Crown-rump length (7-12 weeks) Biparietal diameter (after 12 weeks) Femur length (after 12 weeks) BPD, FL and AC the most important parameters for determination of gestational age Determination of gestational age should be performed prior to 26 weeks gestational age 3rd trimester determination of gestational age does not acurately reflect gestational age

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Fetal growth BPD ~ biparietal diameter FL ~ femur length AC ~ Abdominal circumference Discrepancy resulting from inaccurate dates True intrauterine growth restriction (IUGR) Symmetric - the fetus being small in all parameters, reflects a chronic or long-standing insult and may be caused by low genetic growth potential, intrauterine infection, undernutrition, heavy smoking, or chromosomal aberration. Asymmetric - head and body growth varying, suggests an acute or late-occurring deprivation, such as placental insufficiency resulting from hypertension, renal disease, or cardiovascular disease. Macrosomia - weighing more than 4000 g, associated with maternal glucose intolerance, carries an increased risk of intrauterine fetal death, and at increased risk for trauma during birth.

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16 Ultrasonography: gestational age a In decreasing order b Only if cephalic index ( BPD divided by occipital-frontal diameter ) is normal ( 76-84%) ; otherwise , the fetal head may be dolichocephalic or brachycephalic

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3/18/2014 17 1st trimester fetus CRL

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3/18/2014 18 28 mm CRL in 10 weeks twin pregnancy

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3/18/2014 19 Biparietal Diameter a cross section through the fetal head at the level of the thalamus. The skull is represented by the thick white lines which surround the brain. This view is used to measure the biparietal diameter (line) and the circumference of the head (dots).

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3/18/2014 20 Fetal Femur

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3/18/2014 21 Pregnant uterus - longitudinal

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3/18/2014 22 Fetal : intracranial structure and extremity

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Fetal anatomy Head (ventricles, blood vessels) Neck Spine Heart Stomach Small bowel Liver Kidney Blader Limb

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3/18/2014 24 Fetal Cardiac Structure

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3/18/2014 25 Fetal Liver and Lung interface

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3/18/2014 26 Fetal Liver 3rd Trimester

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3/18/2014 27 Fetal Spine

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3/18/2014 28 Spine3 D

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29 Neural tube defects NTD’s result from failure of tube closure by the 6th weeks gestational age (embryonic age 26 – 28 days ) Various NTD’s anomalies : Anencephaly Encephalocele Spina Bifida

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30 Gross malformation may be detected in 1st trimester sonogram 1: Anencephalus (absence of a major portion of the brain, skull, and scalp) Acrania (partial or complete absence of the cranium).

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3/18/2014 32 Spina Bifida Consist of a hiatus, usually in the lumbosacral vertebrae, through which a meningeal sac may protruded → meningocele 90% of cases, the sac contains neural elements → meningomyelocele The fetal spine should be examined by sonography with: sagittal, tranverse and coronal views

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3/18/2014 33 Spina Bifida

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3/18/2014 34 NEURAL TUBE DEFECTS

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3/18/2014 35 NEURAL TUBE DEFECTS

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36 Fetal anatomyGross malformation may be detected in 1st trimester sonogram 2: Hydrancephaly (the cerebral hemispheres are absent and replaced by sacs filled with cerebrospinal fluid Cystic Hygroma (is a congenital multiloculated lymphatic lesion that can arise anywhere, but is classically found in the left posterior triangle of the neck.

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3/18/2014 37 Abdominal Wall Defects The two most common are : Omphalocele Gastroschisis Can be ascertained early in pregnancy by maternal serum alphafetoprotein screening programs

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38 Gross malformation may be detected in 1st trimester sonogram 3: Omphalocele (abdominal wall defect in which the intestines, liver, and occasionally other organs remain outside of the abdomen in a sac) Gastroschisis (paraomphalocele congenital abdominal wall defect in which the intestines and sometimes other organs develop outside the fetal abdomen through an opening in the abdominal wall)

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OMPHALOCELE

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3/18/2014 40 GASTROSCHISIS

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3/18/2014 41 Duodenal atresia Diagnosed prenatally by the demonstration of the double bubble sign ( distension of the stomach and first part of the duodenum ) Must be differentiated from other cystic structures in the upper abdomen Diagnosis generally is not possible before 24 weeks 30% of cases has been associated with trisomy 21

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42 Gross malformation may be detected in 1st trimester sonogram 4: Fused twins (Siamese twins) are identical twins whose bodies are joined in utero

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43 Fetal genetic Disorders Nuchal Translucency The maximum thickness of the subcutaneus translucent area between the skin and the soft tissues overlying the posterior aspect of the cervical spine in sagital scane plane. (10-14 weeks) A thickness > 3 mm ( sagital plane): 90% trisomy 18 and 13 80% trisomy 21 5% normal

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Placenta position and function Location Relationship between cervical os Maturation

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45 Uterus and Adnexa Cervical incompetence : Tunneling of the internal ( dilatation ) Cervical length < 3 cm Bulging membranes ( with or without prolaps of the cord or fetal parts ) 30 weeks of gestational age: length of cervix more than 3 cm Adnexal mass : Physiological: Diameter corpus luteum at pregnancy about 2 cm Uterine fibroid

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46 Sonographic assesment of the amniotic fluid Normal : at 2nd and 3rd trimester vertical pocket about 2 cm AFI ( amniotic fluid index ): sum of the depth of the largest pocket of fluid in the four quadrants of abdomen AFI < 5 cm : strongly asociated with oligohidramnions postmaturity

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3/18/2014 47 Amniotic Fluid Index

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Interpretation of the AFl 10.1 to 24.0 cm Normal 5.1 to 10.0 cm Borderline Less than or equal 5.0 cm Abnormal (Oligohydramnios) Greater than 24.0 cm Abnormal (Polyhydramnios) Oligohydramnios is associated with congenital abnomalies (ex. renal agenesis) growth restriction fetal distress Polyhydramnios is associated with neural tube defects obstruction of the fetal gastrointestinal tract, multiple fetuses and fetal hydrops

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49 DOPPLER VELOCIMETRY The primary use of Doppler echo shifts in obstetrics have been to detect and measured blood flow Basis of Doppler Velocimetry : The sound of moving blood cells within vasculature generates an effective Doppler Shift There are 2 methods of estimating circulatory hemodynamics : Direct measurement of the volume of blood flow Indirect estimation of flow velocity using wave form analysis

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DOPPLER VELOCIMETRY The shifted frequencies can be displayed as a plot of velocity versus time, and the shape of these waveform can be analyzed to give information about blood flow and resistance in a given circulation Velocity waveforms from umbilical and uterine arteries, reported as systolic/diastolic (S/D) ratio achieve

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51 Most fetuses will achieve an S/D ratios of 3 or less by 30 weeks Persistent elevation of S/D ratios after 30 weeks is associated with IUGR resulting from uteroplacental insuficiency In postterm pregnancies an elevated S/D ratio indicates a poorly perfused placenta Abnormal result are seen with chromosome abnomalities in the fetus DOPPLER VELOCIMETRY

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3/18/2014 52 Fetal Umbilical Cord Doppler

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DOPPLER VELOCIMETRY

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3/18/2014 54 Fetal Breathing Movement

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3/18/2014 55 Fetal Umbilical artery and Bladder

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Biophysical profile (BPP) Real-time ultrasound permits detailed assessment of the physical and physiologic characteristics of the developing fetus and cataloging of normal and abnormal biophysical responses to stimuli. The biophysical profile (BPP) is a noninvasive dynamic assessment of a fetus and its environment by ultrasonography and external fetal monitoring. BPP scoring is a method of fetal risk surveillance based on the assessment of both acute and chronic markers of nonreassuring fetal status. The BPP includes: fetal breathing movements, fetal movements, fetal tone, fetal heart rate patterns by means of a nonstress test, AFV; The fetal response to central hypoxia is alteration in movement, muscle tone, breathing, and heart rate patterns. The presence of normal fetal biophysical activities indicates that the central nervous system (CNS) is functional and the fetus therefore is not hypoxemic

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Biophysical profile (BPP)

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Biophysical profile (BPP) The BPP is an accurate indicator of impending fetal death. Fetal acidosis can be diagnosed early with a nonreactive nonstress test and absent fetal breathing movements. An abnormal BPP score and oligohydramnios are indications that labor should be induced. Fetal infection in women whose membranes rupture prematurely (at less than 37 weeks of gestation) can be diagnosed early by changes in biophysical activity that precede the clinical signs of infection and indicate the necessity for immediate birth. When the BPP score is normal and the risk of fetal death low, intervention is indicated only for obstetric or maternal factors.

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Magnetic resonance imaging

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Magnetic resonance imaging (MRI) Noninvasive radiologic technique Like CT provides pictures of soft tissue Unlike CT is not use ionizing radiation

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Fetal structure Placenta (position, density, and presence of gestational trophoblastic disease) Quantity of amniotic fluid Maternal structures (uterus, cervix, adnexa, and pelvis) Biochemical status of tissues and organs Soft tissue, metabolic, or functional anomalies Magnetic resonance imaging (MRI)

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BIOCHEMICAL ASSESSMENT

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BIOCHEMICAL ASSESSMENT Involves biological examination and chemical determination Procedures used to obtain needed speciment Amniocentesis Percutaneous umbilical blood sampling Chorionic villus sampling Maternal sampling

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BIOCHEMICAL ASSESSMENT. Amniocentesis

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Amniocentesis First introduced by Serr and Fuchs and Riis in the 1950s for fetal sex determination Only at the late 70th a static ultrasound was used to locate the placenta and amniotic fluid pocket Only In 1983, Jeanty reported a technique of amniocentesis ’’under ultrasound vision’’

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Amniocentesis is perform to obtain amniotic fluid, which contains fetal cells. Under direct ultrasonographic visualization, a needle is inserted transabdominally into the uterus, amniotic fluid is withdraw into a syringe, and the various assessment are performed

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Amniocentesis: Indications Genetic disorders women more than 35 years old, with a previous child with a chromosomal abnormality, or with a family history of chromosomal anomalies. Inherited errors of metabolism (such as Tay-Sachs disease, hemophilia, and thalassemia) and other disorders for which marker genes are known may also be detected. Cells are cultured for karyotyping of chromosomes. Karyotyping also permits determination of fetal sex, which is important if a sexlmked disorder is suspected. Alpha-fetoprotein (AFP) levels are assessed as a followup for elevated levels in maternal serum. High AFP levels in amniotic fluid help confirm the diagnosis of a neural tube defect such as spina bifida or anencephaly or an abdominal wall defect such as omphalocele. AFP levels may also be elevated in a normal multifetal pregnancy and with intestinal atresia, presumably caused by lack of fetal swallowing. Assessment of pulmonary maturity L/S > 2:1 Diagnosis of fetal hemolytic disesase bilirubin level < 0.015

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Amniocentesis After 10-14 weeks gestation Early – earlier than 15 weeks Late – second trimester after 15 weeks Only the amniotic (inner) sac should be aspirated Approximately 1 cc for gestational age laboratory failure op to 20%

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Complications Leakage of amniotic fluid (better prognosis than spontaneous leakage) Amnionitis Vaginal bleeding Needle puncture of the fetus Long term complications: Respiratory distress?? Isoimmunization??

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Amniocentesis Maternal complications Hemorrhage Fetomaternal hemorrhage with possible maternal Rh isoimmunization Infection Labor Abruptio placentae Damage to intestines or bladder Amniotic fluid embolism Fetal complications Death Hemorrhage Infection (amnionitis) Direct injury from the needle Miscarriage or preterm labor Leakage of amniotic fluid

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Amniocentesis and HIV positive women Increased rate of vertical transmission Chemoprophylaxis previous to amniocentesis appears to be beneficial in preventing vertical transmission

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Multiple Gestation Three methods: Indigo carmine injection to the first sac A single needle puncture sampling technique (Jeanty 1990) Simultaneous visualization of two needles on each side of the separating membrane (Bahado-Singh 1992) Abortion risk – probably higher Detailed description of fetus position and placental location

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BIOCHEMICAL ASSESSMENT Percutaneous umbilical blood sampling (CORDOCENTESIS)

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CORDOCENTESIS Involves the insertion of the needle directly into fetal umbilical vessel under ultrasound guidance and the removing 1-4 ml of blood

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CORDOCENTESIS Indications for use Prenatal diagnosis of inherited blood disorders Karyotyping of malformed fetuses Detection of fetal infection Determination of the acid-base status of fetuses with IUGR Assessment and treatment of isoimmunization and trombocytopenia in the fetus

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CORDOCENTESIS. Complications Blood leaking from puncture site Cord laceration Thromboembolism Preterm labour Premature rupture of membranes Infections

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BIOCHEMICAL ASSESSMENT Chorionic villus sampling

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Chorionic villus sampling (CVS) Earlier diagnosis and rapid results Performed between 10 and 12 weeks of gestation Removal of small tissue specimen from fetal portion of placenta Chorionic villi originate in zygote and reflects genetic makeup of fetus

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Chorionic villus sampling Was developed in the 80th percutaneous transabdominal transvaginal transcervical

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Chorionic villus sampling (CVS) Complications: vaginal spotting or bleeding immediately afterward, Miscarriage Rupture of membranes, chorioamnionitis. Because of the possibility of fetomaternal hemorrhage, women who are Rh negative should receive immune globulin (RhoGAM) to avoid isoimmunization.

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Chemical determination

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SERUM MARKER Serum marker maternal serum alphafetoprotein MS-AFP maternal unconjugated estriol maternal serum beta-human chorionic gonadotropin (hCG) Others • Pregnancy associated plasma protein - A (PAPP-A) • Inhibin A

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SERUM MARKER Positive test indicates increased risk Negative test indicates no increased risk but not mean normal fetus Multiple fetuses cannot be assessed

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AFP AFP is produced by the fetal liver, and increasing levels are detectable in the serum of pregnant women from 14 to 34 weeks. Approximately 80% to 85% of all open NTDs and open abdominal wall defects Screening is recommended for all pregnant women. If findings are abnormal, follow-up procedures include genetic counseling for families with a history of NTD, repeat AFP, ultrasound examination, and possibly amniocentesis.

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Triple screening (16-18 weeks) Maternal serum alpha-fetoprotein (MS-AFP) Human chorionic gonadotropin (hCG) Unconjugated estriol (UE3) Quadruple Screen (15-22 weeks most accurate 16-18 weeks) AFP hCG UE3 Inhibin

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Quadruple Screen Down Syndrome PAPP-A is low Inhibin A is elevated

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Electronic fetal monitoring

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Indications for Electronic Fetal Monitoring Assessment Using NST and CST Maternal diabetes mellitus Chronic hypertension Hypertensive disorders in pregnancy IUGR Sickle cell disease Maternal cyanotic heart disease Postmaturity History of previous stillbirth Decreased fetal movement Isoimmunization Meconium-stained amniotic fluid at third-trimester amniocentesis Hyperthyroidism Collagen disease Older pregnant woman Chronic renal disease

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Contraindications for Electronic Fetal Monitoring Assessment NST No but results may not be conclusive if gestation is 26 weeks or less. CST : rupture of membranes, previous classic incision for cesarean birth, preterm labor, placenta previa, placenta abruptio multifetal pregnancy, previous preterm labor, hydramnios, more than 36 weeks of gestation, incompetent cervix

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Fetal Responses to Hypoxia or Asphyxia Hypoxia or asphyxia elicits a number of responses in the fetus. There is a redistribution of blood flow to certain vital organs. This series of responses (redistribution of blood flow favoring vital organs, decrease in total oxygen consumption, and switch to anaerobic glycolysis) is a temporary mechanism that enables the fetus to survive up to 30 minutes of limited oxygen supply without decompensation of vital organs. However, during more severe asphyxia or sustained hypoxemia, these compensatory responses are no longer maintained, and a decrease in the cardiac output, arterial blood pressure, and blood flow to the brain and heart occurs, with characteristic FHR patterns reflecting these changes.

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Fetal heart rate terminology Baseline rate -110-160 Bradycardia&Tachicardia Variability -Longterm & Short term Acceleration Deceleration -Early -Late - Varible

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NST is the most widely applied technique for antepartum evaluation of the fetus. Basis: the normal fetus will produce characteristic heart rate patterns in response to fetal movement. can be performed easily in an outpatient setting because it is noninvasive. relatively inexpensive and has no known contraindications. Disadvantages center around the high rate of false-positive results for nonreactivity as a result of fetal sleep cycles, medications, and fetal immaturity. The test is also slightly less sensitive in detecting fetal compromise than are the CST and BPP.

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NST Interpretation Two or more accelerations of 15 beats per minute lasting for 15 seconds over a 20-minute period Normal baseline rate Long-term variability amplitude of 10 or more beats per minute If the test does not meet the criteria after 40 minutes, it is considered nonreactive, in which case further assessments are needed with a CST or BPP. twice weekly (after 28 weeks of gestation) with patients who are diabetic or at risk for fetal death.

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NST Reactive 2 or more accelerations of FHR of 15 beats/min lasting ≥15 sec, associated with each fetal movement in 20-min period Allow to continue Nonreactive Any tracing with either no FHR accelerations or accelerations <15 beats/min or lasting <15 sec throught any fetal movement during testing period CST, BBP Unsatisfectory quality of FHR recording not adequate for interpretation Repeated in 24 hours or CST

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CST Uterine contractions decrease uterine blood flow and placental perfusion. If this decrease is sufficient to produce hypoxia in the fetus, a deceleration in FHR will result, beginning at the peak of the contraction and persisting after its conclusion (late deceleration). Nipple-Stimulated 10 min massage 2 min massage 5 min break Oxitocin-Stimulated 10 U in 1000 ml fluid IV

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CST NEGATIVE No late decelerations, with minimum of three uterine contractions lasting 40 to 60 sec within 10-min period Reassurance that the fetus is likely to survive labor should it occur within 1 wk; more frequent testing may be indicated by clinical situation POSITIVE Persistent and consistent late decelerations occurring with more than half of contractions Management lies between use of other tools of fetal assessment such as BPP and termination of pregnancy; a positive test result indicates that fetus is at increased risk for perinatal morbidity and mortality; physician may perform expeditious vaginal birth after successful induction or may proceed directly to cesarean birth; decision to intervene is determined by fetal monitoring and presence of FHR reactivity SUSPICIOUS Late decelerations occurring in less than half of uterine contractions once adequate contraction pattern established NST and CST should be repeated within 24 hr; if interpretable data cannot be achieved, other methods of fetal assessment must be used* HYPERSTIMULATION Late decelerations occurring with excessive uterine activity (contractions more often than every 2 min or lasting longer than 90 sec) or persistent increase in uterine tone UNSATISFACTORY Inadequate uterine contraction pattern or tracing too poor

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CST

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