Assessment Of Fetal Growth

ESTIMATING FETAL GROWTH

McDonald’s Rule  Method of determining fetal growth

by measuring the fundal height,  The distance from the fundus to the symphysis pubis in centimeters is equal to the week of gestation between 20th and 31st week of pregnancy.

 Fundal height greater than the

standard:  Multiple pregnancy  Miscalculated due date  Large-for-gestational-age infant  Hydramnios  Hydatidiform mole

 Fundal height less than standard  Failure to thrive  Miscalculated due date  Presence of anomaly

Typical Fundal Milestones  12 weeks  Over the symphysis pubis

 2o weeks  At the level of the umbilicus

 36 weeks  At the level of the xiphoid process

ASSESSING FETAL WEL-BEING

FETAL MOVEMENT  QUICKENING  18 – 20 weeks AOG

 Varies especially in relation to sleep

cycles of the fetus and mother activity during observation time.  SANDOVSKY METHOD  Ask mother to lie in a left recumbent

position after a meal and record how many fetal movements she feels over the next hour

 Normal: movement twice every 10

minutes or an average of 10 – 12 times an hour

 CARDIFF METHOD  Count-to-ten method  The mother records the time interval it

takes for her to feel ten fetal movements  Normal: 10 fetal movements in 1 hour

FETAL HEART RATE  Normal: 120 – 160 beats per minute  Can be heard as early as 10th – 11th

week of pregnancy

 NONSTRESS TESTING  Measures the response of fetal heart

rate to fetal movement  When a fetus moves, the fetal heart rate should increase about 15 beats per minute and remain elevated for 15 seconds. It should decrease to its average rate again as the fetus quiets.

 If no increase in beats per minute is

noticeable on fetal movement, poor oxygen perfusion of the fetus is suggested  Results:  Reactive: if two accelerations of fetal heart rage lasting for 15 seconds occur after movement  Non-reactive: no accelerations occur with the fetal movement

 Contraction Stress Testing  Negative (normal): when no fetal

heart rate decelerations are present with contractions  Positive (abnormal): when 50% or more of contractions cause a late deceleration and continues after the contraction)

Comparison between non-stress test and Contraction Test ASSESSMENT

NONSTRESS

CONTRACTION

What is measured

Response of fetal heart rate in relation to fetal movement

Response of fetal heart rate in relation to uterine contractions porduced by nipple stimulation

Normal findings

Tw0 or more No decelerations with accelerations of fetal contractions heart rate of 15 bpm lasting 15 seconds or more following fetal movements in a 20min period

ASSESSMENT

NONSTRESS

CONTRACTION

Safety considerations

Woman should not lie supine to prevent supine hypotension syndrome

In addition to supine hypotension sydrome, observe woman for 30 min afterward to see that contractions are quiet and preterm labor does not begin

ULTRASOUND  Response of waves against objects  Uses:  Diagnose pregnancy  Confirm the presence, size, and location

of the placenta and amniotic fluid  Establish that the fetus is growing and has no gross defects

 Establish the presentation and position    

of the fetus Gender determination Predict maturity by measurement of biparietal diameter. Discover complications of pregnancy Detect retained placenta.

Nursing Responsibilites  Explain procedure and give assurance  Mother should have a full bladder  Instruct mother to drink a full glass of water

every 15 minutes beginning an hour and a half before the procedure  Instruct mother not to void before the procedure

 Place mother in supine position with

abdomen exposed  Place a towel under the right buttocks

 Make sure that the gel used is room

temperature or warmer

ELECTROCARDIOGRAPHY  Fetal HCG may be recorded as early

as the 11th week of pregnancy  Used when a fetal heart anomaly is suspected

Magnetic Resonance Imaging(MRI)  Has the potential to replace or

compliment ultrasound as a fetal assessment technique  Helpful in assessing complications such as ectopic pregnancy or trophoblastic disease

MATERNAL SERUM ALPHAFETOPROTEIN  Alpha-fetoprotein  A substance produced by the fetal liver that

is present in amniotic fluid and maternal serum

 Abnormally high levels  Indicates open spinal (neural tube defects)

or abdominal defects

 Abnormally low levels  Indicates chromosomal defects

AMNIOCENTESIS  Aspiration of amniotic fluid from the

pregnant uterus for examination.  Done 12th – 13th week of pregnancy

 Amniocentesis gives information

of the following:  Color of the amniotic fluid  Normal: color of water; slightly yellow late in pregnancy  Strong yellow color: blood incompatibility  Green: meconium staining

 Lecithin/Sphingomyelin Ratio  Protein components of surfactant  Normal: 2:1  2:5 or 3:1 in patients with diabetes

 Phosphatidyl Glycerol and

Desaturated Phosphatidylcholin  Also found in surfactant  Presence indicate mature lung function

 Bilirubin Determination  Bilirubin is present if there is blood incompatibility  Chromosome Analysis

 Determination of chromosomal diseases  Fetal Fibronectin  A glycoprotein that plays a part in helping the placenta attach to the uterine decidua  Presence indicate damage to fetal membranes

 Inborn Errors of Metabolism  Alpha-fetoprotein

 Complications:  Hemorrhage from penetration of the

placenta  Infectionof amniotic fluid  Puncture of the fetus

 Preparation:  Ask woman to void  Place patient in supine position exposing

abdomen  Take baseline maternal bp and FHB

 Post-procedure  Let woman rest quietly for about 30

minutes  Assess FHB and presence of uterine contractions  If woman has Rh-negative blood, Rho immuno globulin may be administered

PERCUTANEOUS UMBILICAL BLOOD SAMPLING

 AKA Cordocentesis or Funicentesis  Aspiration of blood from the

umbilical vein for analysis  Ultrasound guided procedure

 Includes:  CBC  Direct Coomb’s Test  Blood gases  Karyotyping

 Kleihauer-Betke Test  Test to determine if sample is fetal blood

 Post-procedure RhIG may be given to

Rh negative mothers

AMNIOSCOPY  Visual inspection of the amniotic fluid

through the cervix and membranes with an amnioscope  Use: detect meconium staining

FETOSCOPY  Visualizing the fetus by inspection

through a fetoscope  Uses:  Confirm the intactness of spinal column  Obtain biopsy samples of fetal tissues

and blood samples  Perform elemental surgery

BIOPHYSICAL PROFILE  Combination of 4 – 6 parameters into

one assessment  Fetal breathingmovement  Fetal movements  Fetal tone  Amniotic fluid volume  Placental grading  Fetal heart activity

 AKA fetal Apgar  More accurate in predicting fetal

well-being than any single assessment  Each parameter has a potential score of 2  Interpretation:  8 – 10: fetus is doing well  4 – 6: fetus in jeopardy

Biophysical Profile Scoring ASSESSMENT

INSTRUMENT

CRITERIA FOR A SCORE OF 2

Fetal Breathing

Sonogram

At least one episode of 30 sec of sustained fetal breathing movements within 30 min of observation

Fetal Movement Sonogram

At least three separate episodes of fetal limb or trunk movement within a 30-min observation

Fetal Tone

The fetus must extend and then flex the extremeties or spine at least once in 3o minutes

sonogram

ASSESSMENT

INSTRUMENT

CRITERIA FOR A SCORE OF 2

Amniotic fluid Sonogram Volume

A pocket of amniotic fluid measuring more than 1 cm in vertical diamter must be present

Placental Grade

Sonogram

Placenta is grade 3; grading is based on structure and amount of calcium present

Fetal heart reactivity

Nonstress test

Two or more fetal heart rate accelerations of at least 15 beats/min above baseline and of 15 sec duration occur with fetal movement over a 20-min time period