King Faisal University College of Applied Medical Sciences

Respiratory Care DepartmentMSRT411: Perinatal and Pediatric Respiratory Care

Antenatal Assessment

Ghazi Alotaibi, PhD, RRT

Lec04-Sep26

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What do we mean by …….

Antenatal Assessment??

Why is it important?

Determines the wellbeing of the newborn and chance for survival (mother history)

Maternal History and Risk Factors

Comprehensive maternal history and physical examination is important to point out the risk factors.

Risk factors can be related to mother, during pregnancy, during labor and delivery, or after delivery.

Antenatal assessment starts with determination of risk factors.

Better knowledge about risk factors better preparation to care for the patient.

Risk Factors

Preterm Birth: What is considered preterm?? The second greatest cause of morbidity and

mortality in neonates. Previous preterm birth increases the subsequent

preterm birth: 1 prior = 15% of subsequent preterm birth. 2 prior = 32% of subsequent preterm birth.

Risk Factors

Incompetent Cervix: Caused by cervical trauma, previous surgery, or

may be congenital. Usually leads to membrane rupture and

premature delivery. If severe, a suture around the cervical canal is

performed.

Risk Factors

Maternal Smoking and Alcohol Intake:

In the US, about 10% of pregnant mothers smoke, drink alcohol or use drugs.

Maternal intake of alcohol leads to fetal growth problems.

Smoking HBCO decreases availability of oxygen to placenta and fetus.

Risk Factors

Maternal Hypertension Complicates 6-8% of pregnancies in the US. Hypertension during pregnancy (after W24) is

termed: Preeclampsia. Preeclampsia (High BP, proteinuria, edema) Can lead to placental abruption, and preterm

delivery.

Risk Factors

Diabetes: Increase the risk for CV and CNS malformations,

and metabolic disturbances. When appears during pregnancy (Gestational

Diabetes Mellitus, GDM). Treatment: glycemic control.

Risk Factors

Infections Diseases: Infections can be transmitted to fetus. Early screening and detection of the infection is

important. Complicated by the rupture of the membrane.

Risk Factors

Problems in Placenta, UC, and Fetal Membrane:

premature rupture : causes 50% of preterm births in the US.

UC : Prolapse, short, single artery (3%)Placental problems (see lec. # 3)

Antenatal Assessment

ULTRASOUND

Save as compared to radiography. Uses high frequency sound waves. Hand-held transducer is placed directly over the

mother’s abdomen, and reflected waves are recorded on screen image.

Can give valuable information about pregnancy and fetus (see next slide).

Clinical Uses of Ultrasound Identify pregnancy. Determine fetal age. Observe amniotic fluid

abnormalities. Detect fetal anomalies. Identify placental abnormalities. Determine fetal position. Examine fetal HR, and RR

Antenatal Assessment

AMNIOCENTESIS Is the procedure of obtaining a sample of amniotic

fluid. Usually performed after W15 (w15-20). A needle is inserted through the skin and uterine

wall to the amniotic sac. Insertion is guided by Ultrasound. Sample from amniotic fluid is obtained for analysis. Very safe procedure (complication rate <1%).

What Info can be obtained by doing Amniocentesis???

1. Diagnosis of Genetic and Chromosomal Disorders.

Eg. Down, sickle cell.

By analyzing cells in the amniotic fluid.

2. Lung Maturity Test. L/S Ratio:

(>2 indicates lung maturity)

Falsely high if sample contaminated.

S/A Ratio:>70: mature lung

What Info can be obtained by doing Amniocentesis???

3. Identification of Meconium Staining: Meconium (greenish, thick) is passed to amniotic

fluid due to fetal asphyxia. If aspirated collapse or hyperinflation. Common in postterm fetus (40% in >42 wks)

Antenatal Assessment

FETAL HEART RATE (FHR) MONITORING Heart starts to beat between W16-W20, but beats

can be detected as early as W8. Normal 120-160 bpm. Becomes very common test. Use:

To determine fetal distress. How?

External transducer/electrodes OR electrode over the fetal scalp.

FHR Monitoring

FETAL HEART RATE (FHR) MONITORING FHR is monitored during uterine contraction. During normal contraction (nonstress test NST, and

during contraction stress test CST).

NST

(positive result)

CST

(positive result)FHR rises => 15 beats per minute at least 15 s with mother’s feeling of fetal movement

No late deceleration of FHR is seen with each contraction

FETAL BIOPHYSICAL PROFILE (FBP)

Assessment of fetal well-being suing ultrasound. 8-10 normal 6 : repeat after 24 hrs. 0-4: abnormal, requires careful evaluation and maybe

immediate delivery.

Reading Assignment

Risk Factors

Czervinske p20-24.

Antenatal Assessment

Kent p31-46.