perinatology. risk factors in perinatal period
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Perinatology. Risk factors in perinatal period. By Korda I. Anatomy of a normal placenta :. The placenta provides the fetus with oxygen and nutrients and takes away waste such as carbon dioxide via the umbilical cord. Indicators of High Risk Pregnancy. Maternal age 35 - PowerPoint PPT PresentationTRANSCRIPT
Perinatology. Risk factors in perinatal
period.
By Korda I.
Anatomy of a normal placenta:
The placenta provides the fetus with oxygen and nutrients and takes away waste such as carbon dioxide via the umbilical cord.
Indicators of High Risk PregnancyMaternal age <16 or >35Chronic disease – hypertension, diabetes, cardiovascular or
renal disease, thyroid disorderPreeclampsia- abn hypertension during pregnancyRh isoimmunization- neg and pos in blood coagulationHistory of stillbirthIUGR- baby is smaller than needs to be; Growth RetardationPostterm pregnancy – 2wks past the due dateMultiple gestationHistory of preterm laborPrevious cervical incompetence
Maternal Assessment of Fetal Activity
Fetal movement Vigorous activity reassuringDecreased activity requires immediate follow-upFactors affecting activity
Sound Drugs Sleep Smoking Blood glucose level
UltrasoundHigh frequency sound waves (Real time scanning)Advantages - early detection of fetal anomalies,
accurate determination of gestation, noninvasive and painless, no known harmful effects, use at any time during pregnancy
TypesTransabdominal US- need full bladder, if not full drink 3-4
8oz glasses and rescanEndovaginal US- probe is inserted into vagina (closer to
structures) same preparation. Lithotomy position.
Clinical Applications1st trimester
• Early identification of pregnancy• Observation of FHR and breathing movements• Measurements – biparietal “side bones of head” diameter
of fetal head, crown to rump, fetal femur length, birth weight
• Detection of anomalies• Identification of amniotic fluid index• Location of placenta and grading; to check whether there’s
proper profusion. Lower the number the better.• Detection of fetal death• Determination of fetal position and presentation• Accompanying procedures (ex: Amniocentesis
Doppler Blood Flow StudiesNot same as Doppler fetal hrt tones
Evaluates blood flow in fetus and motherAssesses placental functionHelpful in managing pregnancies with maternal
diabetes, IUGR “term for slowed growth of the fetus during
pregnancy”, preterm labor, prolonged pregnancies, and multiple gestation
Nonstress Test
Evaluate fetal heart rate with fetal activityReassuring if accelerations occur with fetal
movementInterpretation
Reactive – 2 or more FHR accelerations of at least 15 bpm with a duration of at least 15 seconds in a 20 minute interval (desired)
Nonreactive – reactive criteria not met within 30 minutesIf decelerations are noted- phys notified- for further
evalutaion
incr of about 15 bmp lasting 15 sec desired
Fetal Movement
Figure 14–5 Example of a reactive nonstress test (NST). Accelerations of 15 bpm lasting 15 seconds with each fetal movement (FM). Top of strip shows FHR; bottom of strip shows uterine activity tracing. Note that FHR increases (above the baseline) at least 15 beats and remains at that rate for at least 15 seconds before returning to the former baseline.
Ex: Nonreactive NST. Poss sleep or hypoglycemic. Poss treat w/ juice.
Figure 14–6 Example of a nonreactive NST. There are no accelerations of FHR with FM. Baseline FHR is 130 bpm. The tracing of uterine activity is on the bottom of the strip.
Biophysical ProfileAssessment of 5 biophysical variables
1) Fetal breathing movement (US to determine)2) Fetal movement of body or limbs3) Fetal tone (extension and flexion of extremities)4) Amniotic fluid volume5) Reactive NST with activity
Scoring (2 or 0, no in-between) Between 8-10 is good/desired 2 is given for normal 0 is given for an abnormal finding
Contraction Stress TestEvaluates the Respiratory function of the placenta
Does it get O2 to the baby? Test to check if the placenta has the reserves needed during contractions.
Records FHR response to stress of uterine contractionsCompress arteries to placenta
Uterine Contractions induced by nipple stimulation or Oxytocin (Caution: may cause pt to go into labor!)
InterpretationNegative – 3 good contractions lasting 40 seconds in 10 minute interval with no late
decelerationsPositive – persistent late decelerations with more than 50% of the contractions (NOT
THE DESIRED RESULTS)
CST “Contraction Stress Test”
Postive CST- baseline about 150, HR drops w/ contractions
Another example of positive CST.
Figure 14–8 Example of a positive contraction stress test (CST). Repetitive late decelerations occur with each contraction. Note that there are no accelerations of FHR with three fetal movements (FM). The baseline FHR is 120 bpm. Uterine contractions (bottom half of strip) occurred four times in 12 minutes.
AmniocentesisAmniotic fluid obtained by inserting a needle through the
abdominal and uterine wallsPurpose
Genetics - Abnormal AFPFetal lung maturity
Risks Infection (Sterile tech req’d)Pregnancy loss
TestsTriple tests – AFP, hCG, and UE3 (unconjugated estriol/estrogen)L/S ratio- “Lecithin/Sphingomyelin” test for fetal lung maturation; 2:1Fetal maturity indexPhosphatidylglycerol- another phospholipid surfactant
Amniocentesis
Figure 14–9 Amniocentesis. The woman is scanned by ultrasound to determine the placental site and to locate a pocket of amniotic fluid. Then the needle is inserted into the uterine cavity to withdraw amniotic fluid.
Other Fetal Diagnostic Tests Chorionic Villus Sampling – performed at 10 – 12 weeks, off
the placentaPercutaneous Umbilical Blood Sampling-Computed Tomography- obtain maternal pelvic and fetal
diametersMagnetic Resonance Imaging- confirm anamolies, placental
assessment for location and sizeFetal Echocardiography- identify cardiac anomalies- during 2nd
and 3rd trimester
Changes in Fundal Height
Fetal MonitoringFetal heart sounds
Auscultate between 16 and 40 wks by stethoscope, fetoscope, or Doppler
Benefits of fetal monitoring
Procedure
Normal fetal heart rate: 120-160 bpm
Fetoscope
Doppler
Sites for Auscultation ofFetal Heart Tones
Placental insufficiency
It is the failure of the placenta to supply nutrients to the fetus and remove toxic wastes.
When the placenta fails to develop or function properly, the fetus cannot grow and develop normally. The earlier in the pregnancy that this occurs, the more severe the problems. If placental insufficiency occurs for a long time during the pregnancy, it may lead to intrauterine growth retardation (IUGR).
Fetal distress
Decreased movement felt by the mother or Fetal hyperactivity
Meconium in the amniotic fluidCardiotocography signs increased or decreased fetal heart
rate (tachycardia and bradycardia), especially during and after a contraction
Fetal heart rate less than 120 or greater than 170 beats per minute
Progressive decrease in baseline variability
Late decelerationSevere variable decelerations
Fetal distress is defined as depletion of oxygen and accumulation of carbon dioxide,leading to a state of “hypoxia and acidosis ” during intra-uterine life.
Fetal distressBiochemical signs,
assessed by collecting a small sample of baby's blood from a scalp prick through the open cervix in labour
fetal acidosiselevated fetal blood
lactate levels indicating the baby has a lactic acidosis
Causes Abnormal position and
presentation of the fetusMultiple birthsShoulder dystociaUmbilical cord prolapseNuchal cordPlacental abruptionPremature closure of the
fetal ductus arteriosus
Treatment
In many situations fetal distress will lead the obstetrician to recommend steps to urgently deliver the baby. This can be done by labor induction, or in more urgent cases, a caesarean section may be performed.
Intrauterine growth restriction (Intrauterine growth retardation; IUGR)
(IUGR) refers to a condition in which a fetus is unable to achieve its genetically determined potential size.
Screening the fetus for growth restriction
symphysis–fundal height measurements
Biometry and amniotic fluid volumes
Uterine artery Doppler measurement
Umbilical artery Doppler measurement
Three-dimensional ultrasonography
Resuscitation Algorithm:
Why we need to resuscitate:
pH 7.30 pH 7.00 pH 6.80
How often do we use our resuscitation skills?
Bag, Mask, & Oxygen
Warmer & Blankets
Suction Equipment
Laryngoscope and ETT Tube
Universal Precautions
Assessment: ThenAppearancePulseGrimaceActivityRespirations
Apgar score
Assessment: NowPhysiologic Parameters (Apgar’s best)
Questions to ask yourself
BreathingHeart RateColor
• Clear of Meconium?• Breathing or Crying?• Good Muscle tone?• Color Pink?• Term Gestation?
Initial Management: For all deliveries
Provide warmthPosition and Clear AirwayDryGive Oxygen (as
necessary)
Providing Warmth: The cycle of hypothermia
Acidosis
Pulmonary Vasoconstriction
Pulmonary Hypertension
Right to left shuntingHypoxemia
Tissue hypoxia
Anaerobic metabolism
Positioning: Sniffing
The “Trusty” Bulb Syringe
Clear of Meconium?
Color pink?
Pulse Oximetry: Resuscitation monitorNot affected by
acrocyanosisBe patient and get a
readingIf baby in shock, get
central IV access
Breathing or Crying?Indications for PPV (Positive pressure ventilation)Apnea or gaspingHeart rate <100 even if breathing
Persistent central cyanosis (saturation <90%) despite 100% free-flow oxygen
Self-Inflating BagO2 Reservoir
200-750ml Bag size
Pressure manometerattaches
PEEP valve port
CPAP(continuous positive airway pressure (with mask)
Pressure limited ventilation with PEEP
Blended oxygenEliminates variability
associated with bag ventilation
Neopuff
Masks
Smallest sizes are for preterm infants
Make sure the airway is clear
Lift the baby’s jaw into the mask
Keep the mouth slightly open
Rate 40-60
Indications for IntubationMeconium and baby is not vigorousPPV by bag-mask does not result in good
chest risePPV needed beyond a few minutesChest compressions necessaryRoute to administer epinephrineSpecial indications: Prematurity, CDH
Miller 0
Miller 1
>2000 gm
1000-2000 gm
<1000 gm
Stylet
3.5
3.0
2.5
Intubation Technique
Indications for CompressionsHeart rate <60
bpm after 30sec of PPV
Coordinate with ventilation4 events in 2 seconds90 compressions and
30 breaths per minute
One and Two and Three and Breathe
2 seconds
Compressions
2 thumb technique preferred
Medications: EpinephrineIndication: Heart rate <60 after 30
sec of coordinated ventilation and compressions
1:10,000 (0.1mg/ml)Route: ETT or IV0.1-0.3 ml/kg
1ml Term0.5ml Preterm0.25ml Extreme preterm
Extended AlgorithmEndotracheal
Intubation if not already accomplished
Establish IV access with UVC
Stat CXRDiscontinue efforts if
no heart rate after 15 minutes
Indication: Heart rate <60 after 30 sec of coordinated ventilation and compressions
1:10,000 (0.1mg/ml)Route: ETT or IV0.1-0.3 ml/kg
1ml Term0.5ml Preterm0.25ml Extreme
preterm
IV Access: “Low” UVC
VolumeIndication: No response to
resuscitation and evidence of blood loss
Normal SalineRingers or Blood as alternatives
10 ml/kg, may repeatRoute: IV (Umbilical vein)
Sodium BicarbonateIndication: Documented or
assumed metabolic acidosisConcentration: 4.2% NaHCO3
(0.5meq/ml)Dose: 2meq/kgRoute: IV (Umbilical vein)
Naloxone (Narcan)Indication: Severe
respiratory depression after PPV has restored a normal HR and color and…History of maternal
narcotic administration within the past 4 hours
Dose: 0.1mg/kg of 1mg/ml solution
Route: ETT, IV, IM, SQ
Thanks for attention!!!