Fetal Development, Screenings, Diagnostics

Viability

The ability for a fetus to survive outside the uterus defined by fetal weight and pregnancy duration

What is the Threshold of Viability?

22-25 weeks

At How Many Weeks is a Baby Considered a Fetus?

9 weeks

Primary Functions of the Placenta

Oxygenation, nutrition, excretion

Placental Role at 10 Weeks

Placenta takes over the production of progesterone and secretes copious amounts

Placental Role at 11 Weeks

Placenta produces enough progesterone and estrogen to maintain pregnancy

The Umbilical Cord has 2 __________ and 1 ______

Arteries, vein

What is Wharton’s Jelly?

A special, gelatinous connective tissue that surrounds the umbilical cord to protect it while the baby moves around

What is Variable Deceleration?

Temporary drop in fetal HR due to umbilical cord compression

3 Adaptations of Fetal Circulation

Ductus Arterious, Ductus Venosus, Foramen Ovale

What is the Purpose of the Adaptations of Fetal Circulation?

To ensure efficient blood flow and oxygenation to the fetus for proper development

When does Ductus Venosus Close?

When umbilical cord flow stops

When does Ductus Arterious Close?

When arterial O2 rises

When does Foramen Ovale Close?

When the infant breathes after delivery

Unproper closing of any adaptations can lead to _______ ________

Heart murmurs

What Orders should be Anticipated if baby has a Heart Murmur?

Echocardiogram and BP checks

Why are NSAID’s (Ibuprofen) contraindicated during Pregnancy?

They can cause the adaptations to close early

Antigenic factors that determine a baby’s blood type are present at around ___ weeks

6

Respiratory Development at 3-17 Weeks

Respiratory track develops

Respiratory Development at 16-24 Weeks

Bronchi, vascular structures, and primitive alveoli are formed

Respiratory Development at 24 Weeks

Alveoli mature and secrete surfactant

Respiratory Development at 32+ Weeks

Sufficient surfactant levels are present which increases chance of survival

If a Baby is born Pre-Term how do we “Benefit” their Respiratory System?

Giving mom steroids or the baby artificial surfactant

GI Development at 18-22 Weeks

Amniotic fluid is swallowed by fetus to form meconium

GI Development at 26-30 Weeks

Brown fat development starts

Why is Brown Fat Important for Baby’s?

It helps with thermoregulation; babies without brown fat are at risk for hypothermia or hypoglycemia

GI Development at 36 Weeks

Baby’s GI system is fully ready to go

_______ helps form meconium

Bile

Why do we Administer I.M. Vitamin K to Baby at Delivery?

Babies lack Vitamin K making them unable to synthesize coagulation factors; Vitamin K boosts clotting and prevents bleeding

Renal Development at 5 Weeks

Kidneys form

Renal Development at 9 Weeks

Renal system is fully functional

T or F: Fetal urine contributes to amniotic fluid index

T

How does Fetal Urine Contribute to Amniotic Fluid Index?

Babies practice sucking/swallowing with their amniotic fluid and they replenish the amniotic fluid with their urine

Neurologic Development at 4 Weeks

Neural tubes form

Examples of Fetal Stressors that Cause CNS Damage

Poor nutrition, drugs, environmental exposures, hypoxia

Endocrine Development at 12 Weeks

Islets of Langerhans develop

Endocrine Development at 20 Weeks

Babies produce insulin to manage their own glucose levels

What Causes Fetal Hyperinsulinemia?

Maternal hyperglycemia which causes fetal hyperglycemia

Male Reproductive Development at 28 Weeks

Testes descend

Female Reproductive Development at 16 Weeks

Oogenesis is established

What is Pseudomenstruation?

Small amount of blood-tinged discharge in newborn females from the withdrawal of maternal hormones

External Genitalia is well defined at ___ weeks

12

What are Sutures and Fontanels?

Adaptations of the skull that allow for the head to mold in the birth canal

Musculoskeletal Development at 11-12 Weeks

Practice breathing with amniotic fluid begins

Musculoskeletal Development at 16-20 Weeks

Fetal movements can be felt by mom

Around ____ weeks is when subcutaneous fat builds and the fetus becomes “plumper”

32

What is Lanugo?

Fine hair that covers a fetus and can add to thermoregulation

What is Vernix Caseosa?

A white, greasy substance that coats the skin of the fetus to provides protection during gestation and aid in thermoregulation

Passive Acquired Fetal Immunity

Mother to fetus during pregnancy via placenta

Passive Fetal Immunity

Mother to newborn via breastfeeding

2 Types of Maternal Serum Testing

Noninvasive Prenatal Testing and Maternal Serum Alpha-Fetoprotein Testing

Noninvasive Prenatal Testing

Extracting fetal DNA from maternal blood sample to identify chromosomal abnormalities

Maternal Serum Alpha-Fetoprotein Testing

Screening for neural tube defects that is performed between 15-20 weeks

If either Maternal Serum Test is positive we offer invasive procedures that provide _________ results

Diagnostic

Chorionic Villi Sampling

Procedure offered when either Maternal Serum Test is positive AND the mom is in their 1st trimester; Transabdominal or Transcervical

Chorionic Villi Sampling Process

1. Ultrasound taken

2. Needle is inserted into lower abdomen to retrieve cell samples OR catheter is inserted into cervix to retrieve cell samples

Risk Factors of Chorionic Villi Sampling

Infection, bleeding, pregnancy loss

Amniocentesis Procedure

Procedure offered when either Maternal Serum Test is positive AND the mom is in their 2nd or 3rd trimester; shows Alpha-fetalprotein levels and fetal lung maturity

Amniocentesis Procedure Process

1. Ultrasound taken

2. Needle is inserted through the abdomen into the uterus

3. Needle withdraws 20-30 mL of amniotic fluid

Risk Factors of Amniocentesis Procedure

ROM, bleeding

What does High Levels of Alpha-fetalprotein mean?

Neural tube defects are present

What does Low Levels of Alpha-fetalprotein mean?

Chromosomal disorders are present

Percutaneous Umbilical Cord Sampling

Aspiration of fetal blood from the umbilical cord to assess for chromosome mutations, fetal anemia, infections, or thrombocytopenia

What is the 1st Line of Fetal Surveillance?

Fetal movement

When and How Often should Moms do Kick Counts?

After 28 weeks; twice daily at the same time each day

What is a Standard Ultrasound?

An ultrasound to evaluate fetal presentation, amniotic fluid index, placental position, growth parameters, and 20-week anatomy scan

What is a Limited Ultrasound?

An ultrasound looking for specific parameters/information

What is a Specialized Ultrasound?

An ultrasound using specialized equipment to visualize suspected birth defects

Oligohydramnios

Low amniotic fluid volume (< 500 mL) related to poor pregnancy outcomes

Polyhydramnios

Excessive amniotic fluid volume (> 2000 mL) due to maternal diabetes, fetal anomalies, or idiopathic

What is a Biophysical Profile?

A test that combines an ultrasound and fetal health

Biophysical Profile Variables

Fetal breathing movement, gross body movement, tone, AFI, FHR

What is a Non-Stress Test?

A prenatal test that measures fetal heart rate by placing an EFM on mom for 20 minutes; charted as reactive or non-reactive

Non-Stress Test Guidelines

>32 weeks: 15×15 accelerations

< 32 weeks: 10×10 accelerations

T or F: Contractions should NOT be present during a Non-Stress Test

T

What is FHR Baseline?

The average FHR during a 10 minute period; identified over 2 minutes of data

Fetal Bradycardia

FHR below 110

Fetal Bradycardia Causes

Fetal cardiac problem or structural deficit, viral infections, maternal hypoglycemia/hypothermia

Fetal Tachycardia

FHR above 160

Fetal Tachycardia Causes

Maternal fever or infection, fetal anemia, medication, illicit drugs

What is Moderate Variability?

Reliable predictor of normal fetal acid-base balance via EFM

What do Accelerations mean on a Non-Stress Test?

Increases in FHR above baseline that indicate a well-oxygenated fetus

What is a Contraction Stress Test?

A test that evaluates fetal heart rate responses to uterine contractions over 10-20 minutes; desired result is a negative test