Handbook of Abiogenetic Counseling Cystic Fibrosis - Prenatal Diagnosis-2

 18 June 03:44   Cystic Fibrosis - Prenatal Diagnosis

    (I dont anticipate it will be all-important to analysis all of this because they apparently understand added than I do about CF, but this is for my benefit)

    decreased abundance in females due to aberrant cervical fungus that can accord to infertility

    (Details I wont go into actual abundant afresh fro my benefit)

    *CVS is a address in which a sample of placental tissue is obtained

    *The little fingerlike projections of the placenta that are sampled are alleged chorionic villi

    *The villi are acquired from the aforementioned aboriginal beef as the fetus so these beef should accept the aforementioned genes and chromosomes as the fetus and we can attending at the chromosomes in these beef and ascertain the chromosomal abnormalities discussed earlier

    *CVS is performed amid 10 and 12 weeks gestation

    *CVS has been about back 1983 in US

    *Have you heard about amniocentesis?

    *It is a simple medical action that is usually performed afterwards 15 weeks evolution that is acclimated to aphorism out some chromosomal abnormalities including the ones we just discussed that you are at added accident for

    *A baby sample of the amniotic aqueous that surrounds the babyish is taken

    *Within the aqueous are derma beef that accept been sloughed off by the baby.

    *These beef can be developed in a lab and then the chromosomes can be looked at

    *Review beheld aid that compares the two procedures on timing, risk, accurateness etc.

    *determine if the fetus has one of the chromosomal abnormalities we discussed with >99% accurateness for amnio and 98-99% accurateness for CVS

    *DNA acquired from the sample can aswell be acclimated to analysis for CF with about 100 % accuracy

    *determine the babies sex if you would like to know.

    *The aqueous acquired during an amnio aswell acclimated to analysis for accessible neural tube defects such as anencephaly and spina bifida, but CVS deceit (should accept claret test)

    **Spina bifida is area the analgesic bond didnt anatomy appropriately and afraid tissue is exposed

    **It can couldcause motor impairments forth with additional bloom concerns

    **Risks for these do not access with age, but it is activated for at the aforementioned time and the analysis is able to ascertain 99% of ONTDs (if barometer AFP and acetylcholinesterase)

    *CVS does not analysis for NTDs Accordingly it is recommended that a women accept a claret analysis at about 16 weeks to actuate if the fetus is at added accident for a neural tube defect

    *Most bearing defects cannot be detected by amnio or CVS. (Amnio can ascertain about 10% of bearing defects including the ones we discussed).

    *For archetype broken lip, broken palate, congental affection defects, baby chromosomal abnormalities, and some types of brainy amentia will not be detected.

    *Doesnt commonly analysis for additional ancestral disorders unless ordered specifically

    *Most women activated accept account that their adolescent doesnt accept chromosomal abnormalities but it doesnt agreement a advantageous baby. (3-5 out of every hundred babies has a bearing defect).

    *.5% added accident for abundance accident with amnio (1 out of every 200 women who accept an amnio will accept a abortion that is due anon to the procedure) 1% with CVS These risks are aloft the baseline accident of abortion that all women have.

    *Life aggressive problems to the mother are acutely rare

    *Infection can action but attenuate (less than 1 in 1,000 women)

    *Blood accumulation sensitization (Rh - mothers will accept RhoGam afterward procedure)

    *Routine amnio is not associated with added risks of bearing defects in the fetus

    *Scarring of the babyish is accessible but is anticipation to be actual uncommon

    *Extremely low accident of uterine infection

    *Some studies appear a accessible accident of limb defects with CVS while additional studies accept not. Alotof of the defects were acclaimed if the action was performed afore 10 weeks because the limbs advance amid 4-10 wks. If there is an added accident it is about 1 in 3000.

    *Risks are lower if the physician is awful experienced

    *There is a actual baby adventitious of lab absurdity and the charge to echo the procedure

    *CVS has college accident of absurdity 1-2%

    (This is a claimed accommodation and anniversary woman places altered accent on the things that are important to her)

    *Permits abortion at beforehand gestational age

    *1st trimester and humans generally dont understand that she is pregnant

    *Early abortion has been appear to be easier emotionally and physically

    *Allows analysis for a fetus with 21-hydroxylase absence (CAH) autosomal backward action in which shots of dexamethosone can be given

    *They wish advance that the fetus does not accept a chromosomal abnormality

    *Lower accident of abundance accident 0.5% instead of 1%

    *Results are hardly added authentic >99% compared to 98-99%

    *Offers apprehension of accessible neural tube defects (90-96%)

    *However, a affectionate claret analysis (MSAFP) can be performed after in abundance (14-22 wks) and will ascertain 85% of accessible NTDs

    *Procedure is easier and added hospitals accomplish it

    *With CVS there is a greater likelihood of defective added testing due to

    **Laboratory failure

    **Maternal corpuscle contamination

    ***Frequency 1.9%

    ***Not ambiguous for cytogenetics, can be for DNA or biochemical testing

    ***Can be detected by DNA assay using a affectionate claret sample

    **Mosaic or cryptic results

    ***Presence of two or added groups of beef that alter in their chromosome create up

    ***Occurs in 1-2% of CVS samples

    ***less apropos in CVS than amnio because the placental beef are added distantly accompanying they breach off from the beef in the antecedent aboriginal on so fetus ability not allotment aforementioned abiogenetic create up

    **Insufficient sample

    *They wish advance that the fetus does not accept a chromosomal abnormality

    *They dont wish to yield that added accident of miscarriage

    *They are added afraid about the action than they are about accepting a adolescent with a chromosomal abnormality

    *They feel adequate not alive if there is one of these problems until they bear the child

    *They dont feel a charge for advance and would not arrest the fetus behindhand of the result

    *Moral or religious views

    (I WONT go into this abundant detail)

    *Spend added time on the action data if she is absorbed or if bare to create an abreast decision

    **The absolute action from if you access to if you leave will endure about 20-45 account and you can acknowledgment home afterwards it is completed

    **Some physicians crave you to accept a abounding bladder

    **Abdomen is bankrupt and sterilized

    **A bounded analgesic is generally accustomed to aloof the alien layers of derma (this is agnate to the attempt your dentist uses)

    **Ultrasound is acclimated afore and during the action to anticipate area the babyish is and acquisition a abridged of fluid.

    **A aggravate about the amplitude of a aggravate acclimated to draw blood, but best (3) is amid through the belly into the uterus and amniotic sac.

    **The aggravate may assume continued but it is the amplitude that is felt

    **The aggravate is alone in for one or two account while amniotic aqueous is fatigued up through it.

    **Most women address that the aggravate admittance is not as aching as they had expected, but that there is some discomfort.

    **Some address a acerbic awareness if the aggravate first enters the skin

    **Some address that they feel a aciculate affliction or a abbreviating as the aggravate enters the uterus.

    **Others call it as feeing agnate to claret draw.

    **Some acquaintance a awareness of burden in their lower belly as the aqueous is fatigued up through the needle.

    **It is aswell accepted for women to address some accessory uterine airtight (similar to menstrual cramps) during and/or afterwards the procedure.

    **Usually the first little bit of aqueous is alone because it ability accept some of your beef alloyed in.

    **The sample will be about 20cc or 1-2 tablespoons. This aqueous is bound replaced by the baby.

    **The babies affection is monitored by U/S afterwards the procedure

    *Mild airtight is common

    *Spotting occurs in a baby allotment of women

    *After the analysis abstain arduous activities for 24 hours

    *Call the doctor anon if you acquaintance any of the following:

    **severe and assiduous belly affliction and cramps

    **vaginal bleeding

    **vaginal arising of amniotic fluid

    **anything that seems unusual

    *The after-effects will be accessible in about 1.5 to 2 weeks

    *There are two means the action can be performed: Transcervical and Transabdominal

    *Contraindications for both types include:

    **Active vaginal bleeding (must accept chock-full at atomic 1 anniversary ago)

    **Rh sensitization (if already sensitized) if not sensitized Rhogam accustomed to Rh abrogating women to anticipate sensitization

    **Maternal bleeding disorder

    **Fibroids not avoidable

    **Multiple gestation? (usually not attempted)

    *Transcervical

    **Procedure is agnate to a pap smear

    **Vagina and cervix are cleaned

    **Under the beheld advice of ultrasound, a attenuate tube (catheter) amid through the vagina, cervix, and into the placenta

    **Once the catheter is in abode a syringe is attached

    **Suction is activated to abolish the villi while the catheter is removed

    **After the sample is acquired it is beheld beneath a microscope to be abiding the admeasurement and superior is acceptable and addition sample is not needed

    **Sample is placed in a tube of tissue ability average and beatific to a lab for testing

    **Most women address basal ache during the action although it varies

    **The absolute action alone takes about 5 minutes

    **The babys affection exhausted will be monitored

    **Bleeding occurs in up to 10% of women

    **(Easiest to accomplish with after placenta abutting to cervix)

    **(Contraindications for transcervical CVS include: cervical polyps, ever arced sampling pathway, alive animal canker or additional infections)

    **(Large sample is acquired including accomplished villi)

    *Transabdominal

    **Abdomen is apple-pie and xylocaine bang is accustomed to aloof the high layers (similar to attempt accustomed at the dentist)

    **Using ultrasound as beheld guidance, analgesic aggravate is guided through the belly wall, uterine wall, and into the placenta

    **Once in abode a syringe is absorbed to accumulation suction

    **While assimilation is supplied the aggravate is confused aback and alternating through the placenta

    **After sample is acquired it is beheld to create abiding there is abundant and addition sample is not required

    **Sample is then placed in a tube of tissue ability average and beatific to a lab for testing

    **There is a advanced ambit of responses if it comes to how women address the action felt. If the aggravate is amid it may bake for a few seconds. Women address aggregate from balmy airtight to painful, abundant cramping.

    **The absolute action takes about 5 minutes

    **The baby of the fetus will be monitored

    **Bleeding is rare

    **Contraindications for transabdominal CVS include: interceding bowel, the placenta is too far from the affectionate belly apparent (obesity)

    **(Easiest to accomplish with antecedent or fundal placenta)

    **(Smaller sample admeasurement (pieces of the villi) obtained)

    **(Can be performed afterwards 12 weeks, but usually alone if there is not abundant amniotic aqueous for an amniocentesis)

    *No exercise or arduous action for 24 hours

    *No animal intercourse, douching, tub baths, or blockade use for 72 hours

    *Notify the OB in any of the afterward occur:

    **Fever greater than 100.4 degrees F

    **Heavy bleeding or cramping

    **Amniotic aqueous leakage

    *Return for chase up ultrasound (if that is accepted practice)

    *Blood analysis (MSAFP) at 16-18 weeks to analysis for NTDs

    *Ultrasound is recommended at 18-20 weeks

    *Results will be accessible anywhere amid 1-2 weeks depending on which lab it is beatific to (Genzyme 7 days, CHMC about 2 weeks)

    *More than 95% of women accept abating news

    *Remind them that sometimes added aftereffect testing is needed

    *Ask them how they would like to accept their after-effects and if they wish to understand the sex of the fetus

    *Performed at alone few centers in US

    *Closest is Bounded Abiogenetic Convention in Chicago

    *First attack in 1989

    *Can be acclimated to ascertain any abiogenetic action for which there is a acceptable arrangement information

    *Can ascertain accepted aneuploidies and translocations

    *As some as 40 PGD centers accept been accustomed in 17 countries

    *By this time, these centers performed about 3,000 analytic cycles, consistent in added than 500 pregnancies (over 20% abundance rate), and the bearing of about 300 advantageous children.

    *More than two thirds of these analytic cycles were performed in USA, from which the better amount (1,200 cycles) was contributed by RGI. This resulted in 250 pregnancies and bearing of about 200 advantageous children

    *At present, RGI (Chicago) is the alone centermost in the apple alms Preimplantation Analysis by sampling the first and additional arctic bodies.

    *he first arctic physique is alone during oocyte maturation, above-mentioned to fertilization and contains one set of bifold chromosomes

    *the additional arctic physique is alone afterwards fertilization and contains one set of chromatids

    *test the arctic bodies for abiogenetic ache to actuate if egg has mutation

    *offered to couples who are accepted carriers of abiogenetic diseases apparent by DNA analysis

    *RGI physicians accept already performed over 100 analytic cycles involving preimplantation analysis some abiogenetic diseases including CF

    *diagnosis of Down affection and additional accepted aneuploidies

    *analysis of the chromosome amount (13, 16, 18, 21) in both the first and additional arctic physique by FISH

    *Only embryos consistent from the fertilization of eggs with accustomed amount of these accurate are transferred

    *patients may accept which embryos they ambition to be transferred or frozen. The action has been offered to over 600 IVF couples

    *resulted in 131 births of advantageous accouchement and dozens advancing pregnancies accepted to be artless by CVS or amniocentesis

    *Preimplantation analysis via blastomere biopsy is aswell performed for additional specific disorders involving benevolent genes or sex alternative for X-linked disorders and if accomplishing IVF aeon alfresco of

    *Cost (probe development $1,000, PGD for one aeon $3,000, IVF one aeon $7,500 IVF meds $2,000-$4,000, amount to forward embryologist to your IVF centermost $2,000 Absolute $13,500-$17,500 per cycle

    *Assess if there are any questions or additional apropos throughout the session

    *Assess afresh how she feels about the analysis options

    *Offer accommodating abstract (already beatific according to blueprint note)

    *Bianchi, D.W., Crombleholme T.M., Dalton, M.E. Fetology: Analysis & Administration of the Fetal Patient. McGraw Hill, New York, 2000.

    *http://www.modimes.org/HealthLibrary2/FactSheets/ChorionicVillusSampling.htm

    *www.geneclinics.org

    *Bianchi, D.W., Crombleholme T.M., Dalton, M.E. Fetology: Analysis & Administration of the Fetal Patient. McGraw Hill, New York, 2000.

    *http://www.noah-health.org/english/pregnancy/march_of_dimes/testing/amniocen.html#Amniocentesis

    *Kuller, J.A., Chescher, N.C., Cefalo, R.C. Prenatal Analysis and Changeable Genetics. Mosby Year Book Inc. 1996.

    *http://www.reproductivegenetics.com/preimplantation.shtml

    The advice in this outline was endure adapted in 2000.