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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.

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Determination of estimated birth 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
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 development1
Fetal Growth and Development

Estimated 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 development2
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
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 being1
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.

Assessing fetal well being2
Assessing Fetal Well-Being

  • 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.

Assessing fetal well being3
Assessing Fetal Well-Being

  • 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.

Assessing fetal well being4
Assessing Fetal Well-Being

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

Assessing fetal well being5
Assessing Fetal Well-Being

  • 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.

Assessing fetal well being6
Assessing Fetal Well-Being


  • 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

Assessing fetal well being7
Assessing Fetal Well-Being

  • 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 sonogram

    Biparietal Diameter:

  • measures side to side measurement of fetal head (8.5cm or more infant weighs > 2500g 5.5 lb) 40 week gestation.

Assessing fetal well being8
Assessing Fetal Well-Being

  • 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 being9
Assessing Fetal Well-Being

ECG 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.

Assessing fetal well being10
Assessing Fetal Well-Being

Triple Screening - analysis of 3 indicators:

  • Maternal serum Alpha-fetoprotein

  • unconjugated estriol

  • hCG

  • used for Downs syndrome

    Chorionic Villi Sampling (CVS)

  • biopsy and analysis for chromosomal analysis done at week 10 to 12.

Assessing fetal well being11
Assessing Fetal Well-Being


  • 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

Assessing fetal well being12
Assessing Fetal Well-Being


  • 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

Assessing fetal well being13
Assessing Fetal Well-Being

  • 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

Assessing fetal well being14
Assessing Fetal Well-Being

  • Alpha-Fetoprotein

    Percutaneous Umbilical Blood Sampling

  • aspiration of blood from the umbilical vein for analysis


  • visual inspection of amniotic fluid through the cervix and membranes with a small fetoscope (detects meconium).


  • visualizing the fetus with fetoscope

Assessing fetal well being15
Assessing Fetal Well-Being

  • confirms intactness of spinal column

  • biopsy of fetal tissue and blood sample

  • surgery

  • photos

  • done week16 to17 at the earliest

  • risks-premature labor, infection


Assessing fetal well being16
Assessing Fetal Well-Being

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.