1. Assessment of Fetal Growth & Development
Module B – Part I

2. Objectives List three maternal-fetal risk factors.
Differentiate between the various ways to assess fetal growth, development, and status.
Differentiate between the various abnormal heart rate patterns.
Describe the significance of meconium in the amniotic fluid.

3. Antenatal Assessment Antenatal = Prenatal Includes
Maternal History
Evaluation of Maternal-Fetal Risk Factors
Physical Assessment
Intrapartum Monitoring
High Risk Conditions
Maternal mortality: 6 of 100,000 births
Perinatal mortality: 17 of 1,000 births

4. Maternal History & Risk Factors
Preterm Birth
Birth before 37 weeks is the greatest cause of neonatal morbidity and mortality.
8% of births.
Smaller the infant, greater the risk.
Consequence of:
Preterm labor
Preterm rupture of membranes
Fetal or maternal distress
Prior preterm births
1 prior preterm birth: 15% risk of subsequent
2 prior preterm births: 32% risk
Uterine Malformation and Incompetent Cervix

5. Maternal History & Risk Factors
Toxic Habits in Pregnancy
Present in 10% of pregnancies
Smoking
CO & Nicotine decrease fetal oxygen delivery.
Correlation between cigarette smoking & low birth weight.
Associated with:
Premature membrane rupture
Placental disorders
SIDS
Alcohol Use
Teratogenic
Fetal Alcohol Syndrome

6. Maternal History & Risk Factors
Toxic Habits in Pregnancy
Illicit Drug Use
Cocaine is a potent vasoconstrictor:
Reduced maternal coronary blood flow.
Reduced placental blood flow.
Opiates and Amphetamine use are shown to result in depressed neonatal function & withdrawal symptoms.
Poor Nutrition
Presence of Diabetes
Lack of Prenatal Care

7. Maternal History & Risk Factors
Multiple Births
Maternal Infection
Group B Streptococcus
Herpes Simplex Virus
HIV & Hepatitis B
Abnormalities of the Placenta, Umbilical Cord & Fetal Membranes
See Below
Disorders of Amniotic Fluid Levels
Mode of Delivery
Toxemia

8. Toxemia Complicates 6 to 8% of deliveries
2nd only to pulmonary embolism as cause of maternal death.
Preeclampsia –
A blood pressure greater than 140/90 mm Hg.
A rise in blood pressure greater than 30 mm Hg systolic or 15 mm Hg diastolic during pregnancy.
Proteinuria
Edema of face & hands
Pressures over 150/100 mm Hg is considered severe preeclampsia.
If not treated can lead to Eclampsia.

9. Toxemia
Eclampsia – Occurrence of 1 or more convulsive seizures not attributed to other cerebral conditions, during pregnancy.
Occurs in 1 of 200 preeclamptic patients.
Coma.
Seen between 20 weeks and term.
May be fatal if untreated.
Can occur post-delivery.

10. NEONATAL ASPHYXIA
Combination of hypoxia, hypercapnia and acidosis leads to neonatal asphyxia.
Asphyxia leads to irreversible damage to the brain and vital organs.
Asphyxia can occur in utero or during the delivery.
GOAL SHOULD BE TO IDENTIFY AND PREVENT ASPHYXIA.

11. Causes of Neonatal Asphyxia
Maternal hypoxia or asphyxia.
Decreased placental blood flow.
Anemia of the fetus.
Drugs taken by the mother or given to the mother.

12. Assessment of the Fetus
Ultrasonography
Amniocentesis
Fetal Biophysical Profile
Nonstress/Contraction Stress Testing
Fetal Heart Rate Monitoring
Fetal Blood Scalp Blood Analysis

13. Ultrasonography
Uses high frequency sound waves to locate and visualize organs and tissues.
Placental placement.
Amniotic fluid volume.
Assess fetal growth.

14. Amniocentesis
Amniocentesis is obtaining a sample of amniotic fluid for testing purposes
inch 20 – 22 gauge needle
Guided by ultrasound
Can be performed at 15 weeks but more commonly during the 2nd & 3rd trimester
Complications are infection, trauma and hemorrhage

15. Amniocentesis L/S ratio PG (Phosphatidylglycerol)
Alpha Fetoprotein (AFP)
Sign of skin rupture
Cytology of cells
Creatinine
Bilirubin
Detection of meconium
Fetal fecal matter

16. Biophysical Tests of Fetal Well-Being
A prenatal “APGAR” score
Score of 0 (abnormal) or 2 (normal) on 5 variables:
Fetal Breathing (1 breath in 30 seconds) - U
Fetal Movement (3 movements in 30 minutes) - U
Fetal Limb Tone (1 extension/flexion in 30 minutes) - U
Reactive Fetal Heart Rate (2 reactive episodes [acceleration of FHR >15 bpm] in 20 minutes) - NST
Amniotic Fluid Volume (One 1x1 cm pocket) - U
Normal Score is 8-10
10 is normal; 0 to 4 abnormal.
TABLE 3-1 p. 26

17. Fetal Heart Rate Monitoring
Average fetal HR is 140/min (120 to 160/min)
Decreases to 120/min near term.
Fetal Heart Rate Monitoring can determine fetal distress.
Fetal Heart Rate Monitoring is correlated with uterine contractions during labor.

18. Fetal Heart Patterns Baseline Heart Rate Bradycardia Tachycardia
Less than 120 beats/minute or a drop of 20 beats/minute or more from baseline heart rate.
Common causes:
Asphyxia (rule out immediately)
Give the mother oxygen may help.
Fetal scalp sample for pH determination.
Congenital Heart Defects
Hypothermia
Drugs/medications given to mother
Tachycardia
HR above 160/min
Causes
Maternal Fever/Infection
Infection of the fetus
Maternal dehydration
Maternal anxiety
Asphyxia
Drugs given to the mother

19. Fetal Heart Patterns
Decelerations: HR drops below 120/min for less than 2 minutes.
Early Decelerations (Type I)
Usually due to fetal head compression.
Poses little threat to fetus.
Late Decelerations (Type II)
Uteroplacental insufficiency.
Begin at peak of contractions.
Associated with fetal distress.
Variable Decelerations (Type III)
Most common.
Cord compression.
May indicate fetal hypoxia.
Usually doesn’t correlate with contractions

20. Early or Type I Decelerations

21. Late or Type II Decelerations

22. Variable or Type III Decelerations

23. Fetal Scalp pH Assessment
Asphyxia results in a drop of pH
Increase in PaCO2
Anaerobic metabolism resulting in increased lactic acid.
Procedure
Mother is placed in a lithotomy position.
Fetal head is visualized through the cervix.
An incision is made in the scalp and a blood sample is obtained.

24. Fetal Blood pH Normal fetal blood pH is above 7.25
pH between 7.15 – 7.24
Slight asphyxia
pH less than 7.15
Severe asphyxia
The pH of the mother should be determined concurrently

25. Estimated Date of Confinement (EDC)
Delivery Date
None of the methods are exact
Nägele’s Rule
Fundal Height
Quickening
Determination of Fetal Heartbeat

26. Nägele’s Rule Most common method used to determine EDC Example:
Subtract 3 months from the first day of the last menstrual period.
Add 7 days
Example:
First day of last menstrual period is 3/25
Subtract 3 months = 12/25
Add 7 days = January 1

27. Fundal Height
The Fundus of the uterus is the end opposite the cervix and can be measured as the uterus grows with the fetus
Unreliable during the last trimester
A measurement is taken from the symphysis pubis to the top of the fundus
If the distance is 20 cm, the gestation is 20 weeks.

28. Quickening
Quickening is the first sensation of fetal movement experienced by the mother.
16 – 22 weeks (average is 20 weeks).
Very rough estimation of fetal age.

29. Determination of Fetal Heartbeat
Fetal heartbeat can be heard as early as 16 weeks.
Nearly always heard by 20 weeks.
With the use of Doppler devices, the heartbeat can be heard earlier (8 weeks).

30. Meconium Presence in Amniotic Fluid
Meconium is the thick, dark greenish stool found in the fetal intestine.
Passage of the meconium into the amniotic fluid occurs in 40% of post-term fetuses of greater than 42 weeks gestation.
This occurs due to asphyxia.
Meconium release may result in meconium aspiration syndrome (MAS).