determination of estimated birth date it is impossible to predict the day of birth. estimated date...

Determination of Estimated Birth Date

It is impossible to predict the day of birth.Estimated date of birth - EDB, EDD or EDC.280 days - 38 to 42 weeks in length.

Nagele’s rule:• 1st day of last menstrual period.• Count back 3 months and add 7 days.• Normal variations - if ovulation and

fertilization occurs early or late in the menstrual cycle the pregnancy may be 2 weeks before or 2 weeks after the EDD.

Fetal Growth and Development• Nurses responsibility– signed consent form with information on the

procedure and possible risks– scheduling the procedure– explaining the procedure to the woman and support

person– preparing the woman physically and psychologically– providing support during the procedure– assessing both fetal and maternal responses to

procedures– provide follow up care– manage equipment and specimens

Fetal Growth and DevelopmentEstimated Fetal Growth:

• McDonald’s rule - method of determining, during mid pregnancy, that the fetus is growing in utero by measuring fundal (uterine) height.

• Distance from fundus to symphysis in centimeters is equal to the week of gestation between week 20 to 31.

• Measure from the notch of the symphysis pubis to over the top of the fundus with woman lies supine.

• This becomes inaccurate in 3rd trimester because the fetus is growing in wt. than height.

• Milestones:– 12 weeks- over symphysis pubis– 20 weeks at umbilicus– 36 weeks xiphoid process

Fetal Growth and Development

Assessing Fetal Well-Being:• Fetal movement - quickening week 18 to 20• peaks at week 28 to 38 • healthy fetus moves 10 times a day.• Ask mother to lie in left recumbent position

after a meal and record number of fetal movements in next hour.

• 2 times in 10 minutes• fewer than 5 in 1 hour - notify the doctor.

Assessing Fetal Well-Being

Fetal Heart Rate:• 120 to 160 beats per minute throughout

pregnancy.• Week 10 to 11 heart sounds can be heard

and counted with a doppler.Rhythm Strip Testing:• baseline fetal heart rate per minute and

long and short term variability.• Place woman in semi-fowlers (prevents

supine hypotension syndrome).

Assessing Fetal Well-Being• Monitors are attached abdominally and

recorded for 20 minutes (mother in fixed position)

• Short term variability- beat to beat variability- denotes small changes in rate from second to second if parasympathetic nervous system is receiving adequate O2 and nutrients.

• Long term variability - denotes the differences in heart rate that occur over 20 minutes (fetus moves 2x/10 min) increases with movement.


• This reflects fetal sympathetic nervous system.

Nonstress Testing:• measures response of fetal heart rate to

movement.• Monitors are attached to abdomen• mother pushes a button attached to the

monitor when she feels the fetus move.• FHR should increase 15 beats/ min and

remain elevated for 15 seconds.


• Decreases when fetus quiets. If no increase is noticeable with movement poor O2 perfusion of fetus id suggested.

• Test lasts 10 to 20 minutes.• If no fetal movements in 20 minutes fetus

may be sleeping.• Orange juice or carbohydrate may increase

blood glucose level which stimulate the fetus. Also loud noise may stimulate fetus.


Vibroacustic Stimulation:• Acustic stimulation (artificial larynx) applied

to abdomen to produce a sharp sound, startling and waking the fetus.

• 80 dB frequency of 80 Hz.Contraction Stress Testing:• FHR is analyzed in conjunction with

contractions.• Mother stimulates the nipple which

releases oxytocin which initiates uterine contractions


• External uterine contraction and FHR monitors are applied

• 3 contractions with duration of 40 seconds or more present in a 10 minute period.

• Normal (negative) when no FHR decelerations are present with contractions.

• Abnormal (positive) 50% or more contractions cause a late deceleration (dip in FHR) toward the end of a contraction and continues after the contraction.

• Woman waits 30 min after the test.


Ultrasound:• response of sound waves against objects.• Diagnose pregnancy at 6 weeks gestation• confirm presence, size, and location of

placenta and amniotic fluid.• Establishes fetal growth, gross defects• Establish presentation and position (sex)• Predict maturity by biparietal diameter• Mother has to have a full bladder ( drink a

full glass of water q 15 min. in 1 1/2 hours


• Place a towel under the right buttock to tip uterus away from the vena cava.

• Gel applied to abdomen (room temperature)

• Transducer is applied intravaginal or abdominal

• Picture of sonogramBiparietal Diameter:• measures side to side measurement of fetal

head (8.5cm or more infant weighs > 2500g 5.5 lb) 40 week gestation.


• Also measures head circumference and femoral length.

Doppler Umbilical Velocimetry:• Measures velosity at which RBC and vessels

are traveling.Placental Grading:• amount of calcium deposits in base of

placenta.Amniotic Fluid Volume Assessment:• average index is 15 cm between 28-40 wks.

Assessing Fetal Well-BeingECG at week 11 of pregnancy (inaccurate

before week 20 because fetal electrical conduction is week).

MRI used to diagnos ectopic pregnancy or trophoblastic disease.

Maternal Serum Alpha-Fetoprotein is a substance produced by the fetal liver that is present in amniotic fluid and maternal serum. Begins to rise at week 11.

• Detects Down Syndrome, open spinal or abdominal defects.


Triple Screening - analysis of 3 indicators:• Maternal serum Alpha-fetoprotein• unconjugated estriol• hCG• used for Downs syndromeChorionic Villi Sampling (CVS)• biopsy and analysis for chromosomal

analysis done at week 10 to 12.


Amniocentesis:• aspiration of amniotic fluid from the uterus

for examination.• Week 12 to 13 • 1 mL of fluid is needed• 3 to 4 in 20 to 22 gauge spinal needle• woman rest for 30 minutes after the

procedure• constant monitoring for FR and

contractions• if Rh-neg. blood give RhoGAM


Amniocentesis:• color of water or slight yellow tinge– strong yellow- bilirubin– green- meconium

• lecithin/ sphingomyelin ratio–protein components of lung enzyme

surfactant that alveoli form week 22-24• phosphatidyl glycerol and desaturated

phosphtidylcoline– found in surfactant


• Bilirubin Determination–must be blood free to analyze bilirubin

• Chromosome Analysis–uses fetal skin cells for karyotyping

• Fetal Fibronectin– glycoprotein that helps placenta attach

to the uterine decidua ( preterm labor).• Inborn Errors of Metabolism– inherited diseases from inborn errors


• Alpha-FetoproteinPercutaneous Umbilical Blood Sampling• aspiration of blood from the umbilical vein

for analysisAmnioscopy• visual inspection of amniotic fluid through

the cervix and membranes with a small fetoscope (detects meconium).

Fetoscopy• visualizing the fetus with fetoscope


• confirms intactness of spinal column• biopsy of fetal tissue and blood sample• surgery• photos• done week16 to17 at the earliest• risks-premature labor, infection.


Biophysical Profile (fetal Apgar)• combines 4 to 6 parameters into one

assessment– fetal movement and breathing, fetal

tone, amniotic fluid volume, placental grading

fetal heart reactivity.–more accurate in predicting well being

than any single assessment.– a score of 4 to 6 denotes a fetus in

jeopardy.

determination of estimated birth date it is impossible to predict the day of birth. estimated date...

Documents

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fetal wellbeing ultrasound

fetal wellbeing decreases

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baseline fetal heart

minutes fetus

assessing fet