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!!!