1. Antenatal Care
DR. Yasir Katib
MBBS, FRCSC
Perinatologest

2. Antenatal care (ANC) goals and strategy
Explain the components and objectives of prenatal goals
Describe the frequency and aim of each prenatal visit
Genetic counseling and its available tools
Risks and benefits of the genetic tests

3. ANC Objectives
To ensure the birth of a healthy baby with minimal risk for the mother by
Early, accurate estimation of GA
Identification of the patient at risk for complications
Ongoing evaluation of the health status of both mother and fetus
Anticipation of problems and intervention, if possible, to prevent or minimize morbidity
Patient education and communication

4. ANC Prenatal care is not a single intervention
“Quantity" Vs. “Quality" of ANC
A systematic review of observational studies and randomized trials concluded that there was no conclusive evidence that prenatal care improved birth outcomes
Randomized trials have also shown that enhanced prenatal care did not result in improved outcomes compared to routine prenatal care

5. ANC Components HISTORY PHYSICAL EXAMINATION LABORATORY TESTS
DIAGNOSTIC IMIGING
PATIENT EDUCATION
MEDICATIONS

6. HISTORY Personal and demographic information
Current pregnancy history (dating)
Past obstetrical history (time, place, GA, complications, sex, weight& currant status)
Personal and family medical history
Past surgical history
Genetic history
Menstrual and gynecological history
Psychosocial information

7. Physical examination A complete physical examination Specially…
Uterine size and shape
Evaluation of the adenexea
Baseline blood pressure, weight, and height

9. LABORATORY TESTS 1st visit
A standard panel of laboratory tests (Routine)
CBC
Blood gp & antibodies screen
HbS Ag
Rubella
VDRL
Urine C&S
Cervical PAP smear

10. LABORATORY TESTS 1st visit
In high risk population
Chlamydia swab
HIV
TFT

11. LABORATORY TESTS others
N. gonorrhea TB
Toxoplasmosis
HCV BV
Others HB electrophoresis, cystic fibrosis, phenylalanine level …etc

12. Follow-up visits Major goals (PET, malpresentation) Components
Wt, B/P, SPH, FH auscultation, FM, lie, presentation
Patient’s concerns
Education
Risk identifications

13. Presentation & lie

14. Follow-up visits Uncomplicated pregnancies Every 4 weeks until 28 wks
Every 2 to 3 weeks from 28 to 36 wks
Weekly until delivery

15. Follow-up visits Laboratory follow-up GDM screening at 24-28 wks
CBC & antibodies screen
GBS screening (recto-vaginal swab) at wks

16. DIAGNOSTIC IMIGING Ultrasound Minimum requirement Usefulness
Limitations
Others
MRI

18. 1st Trimester U/S Confirm pregnancy Viability Assess GA (Dating)
Multiple gestations (chorionicity / amnionicity)
Maternal pelvic anomalies
AIUM Standards and Guidelines

19. 2nd Trimester U/S Fetal normality:
• Head shape and size and internal structures (cavum pellucidum, cerebellum, ventricular size at atrium < 10 mm)
• Spine: longitudinal and transverse
• Abdominal shape and content at level of stomach
• Abdominal shape and content at level of kidneys and umbilicus
• Renal pelvis < 5 mm anterior–posterior measurement
• Longitudinal axis abdominal–thoracic appearance (diaphragm and bladder)
• Thorax at level of a four-chamber cardiac view
• Arms: three bones and hand (not counting fingers)
• Legs: three bones and foot (not counting toes)

20. VALUE OF PRENATAL GENETIC DIAGNOSIS: Why do we do it?
Reassurance
Increases options
Antenatal fetal treatment
Preparation for outcome
Avoidance of obstetric complications
Selective termination

21. 1/200 chance of abnormality
Maternal age-based screening
Rationale
70%
30%
1/200 risk of miscarriage
1/200 chance of abnormality = =

22. Assessment of Background Risk
Maternal Age
0.0001
0.001
0.01
0.1 1 10 20 25 30 35 40 44
Years
Trisomy 21
47xxx/xxy/xyy
Risk %
Trisomy 18
Trisomy 13
45x
Triploidy
Courtesy Dr J Johnson and the Fetal Medicine Foundation

23. Assessment of Backround Risk
Gestational Age % 20 40 60 80
100 10 14 18 25 30 35
Weeks
Trisomy 21
Trisomy 18
Trisomy 13
Triploidy
47xxx/xxy/xyy
45x
Courtesy Dr J Johnson and the
Fetal Medicine Foundation
Snijders et al 1999

24. Prenatal Screening Modalities

25. Allows adjustment of age-related risk Improved detection rate
Screening at wks
wks
Allows adjustment of age-related risk
Improved detection rate
Courtesy Dr J Johnson and the Fetal Medicine Foundation

26. A- Non-invasive prenatal diagnostic tests
Nuchal Screen
Nuchal plus biochemistry
Maternal Serum Screen
Ultrasound

27. Nuchal Translucency 1-
“the skin is deficient in elasticity too large for the body”
Langdon Down
Observations on an ethnic classification of idiots.
Clinical Lecture Reports, London Hospital 1866;3:259.
Courtesy Dr J Johnson and the Fetal Medicine Foundation

28. Gestation 11-14 wks CRL 45-84 mm Mid-sagittal view Image size >75%
Nuchal Translucency
Gestation wks
CRL mm
Mid-sagittal view
Image size >75%
Neutral position
Away from amnion
Maximum lucency
Calipers on-to-on
Courtesy Dr J Johnson and the Fetal Medicine Foundation

29. Significance of increased nuchal fluid
Chromosome abnormalities
Birth defects (cardiac, d.hernia)
Genetic syndromes
Increased mortality (> 3.5 mm)
Courtesy Dr J Johnson and the Fetal Medicine Foundation

30. Pathophysiology of increased
nuchal translucency
Abnormal or delayed lymphatic development
Venous congestion
Cardiac failure
Altered composition of extracellular matrix
Failure of lymphatic drainage due to fetal hypokinesia
Fetal anemia or hypoproteinemia
Congenital infection
Courtesy Dr J Johnson and the Fetal Medicine Foundation

31. First Trimester Biochemical Markers2-
PAPP-A: Pregnancy associated plasma protein A
Produced by placental trophoblast
Increases in week period
Lower in DS pregnancies (0.43 MOM)
Associated with 42 % DR at 5% FPR.
Free - hCg: Free  subunit of human chorionic gonadotrophin.
Placental protein
Decreases in T1 like total hGC
Higher in DS pregnancies (1.79 MOM)
Associated with 23% DR at 5% FPR
Courtesy Dr J Johnson and the Fetal Medicine Foundation

32. Fetal NT + Maternal age + ßhCG + PAPP-A at 11-14 wks
Screening at wks
Fetal NT + Maternal age + ßhCG + PAPP-A at wks
Invasive
Testing 5%
All 20 40 60 80
100 %
Age
ßhCG
PAPP-A
Detection Rate
30%
89%
72%
60% NT
Courtesy Dr J Johnson and the Fetal Medicine Foundation

33. 3- Maternal Serum Screen
Three biochemical markers
BHCG
AFP
Estriol
Gives age adjusted risk
Screens for Down’s and NTD
15-20 wks

34. MSS
1/1
1/378
Risk = age X OR BHCG X OR uE3 X OR AFP

35. MSS Limitations Sensitivity 70 % Specificity 95% ( False positive 5%)
Two reasons for a false positive:
Wrong dates
Twins

36. 4- Ultrasound
Ultrasound screening (detailed scan)
18-20 weeks

37. B- INVASIVE TECHNIQUES FOR EARLY PRENATAL TESTING
Chorionic Villus Sampling
Amniocentesis

38. Amniocentisis http://wchs.health.wa.gov.au/health/a/amnio.htm

39. Amniocentisis Performed at or more 15 weeks
Takes 2-3 weeks for Karyotype
Pregnancy loss risk 1/200
Can get result of trisomies 13,18,21 and Turners Syndrome X0 in 48 hours with FISH (Florescent Insitu Hybridization)

41. Chorionic Villus Sampling
Performed at weeks
Takes 2-3 weeks for the result
Pregnancy loss rate 1/100
Operator experience important
Link to limb abnormalities (still controversial)
Placental mosaicism up to 3%, but little effect on outcome

42. Post Test
A standard panel of laboratory tests (Routine) dose not include
Rubella
TFT
VDRL
Urine C&S
Cervical PAP smear

43. Post Test First trimister scan does not include Fetal morphology
Viability
Assess GA (Dating)
Multiple gestations (chorionicity / amnionicity)
Maternal pelvic anomalies

44. Post Test Which of the following is not a cause for an abnormal MSS
Down’s syndrome
IUFD
Twins
Wrong dates
Congenital heart disease

45. Post Test
A false positive on the MSS occurs in 1/20 tests
True
False

46. Post Test List Two advantages of Amniocentesis over CVS
Decreased miscarriage rate
Lower risk of mosaicism
No association with limb reductions

47. Post test
Which of the following tests is the best at detecting Down’s Syndrome
MSS
Nuchal
Nuchal plus PAPP A and Free BHCG

48. Post Test What is the miscarriage rate with amniocentesis? 0.5% 3% 5%
10%

49. Post Test
List one advantage of CVS over amniocentesis
Early results