Antenatal Care DR. Yasir Katib MBBS, FRCSC Perinatologest

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

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

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

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

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

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

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

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

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

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

Presentation & lie

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

Follow-up visits Laboratory follow-up GDM screening at 24-28 wks CBC & antibodies screen GBS screening (recto-vaginal swab) at 35-37 wks

DIAGNOSTIC IMIGING Ultrasound Minimum requirement Usefulness Limitations Others MRI

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

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)

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

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

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

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

Prenatal Screening Modalities

Allows adjustment of age-related risk Improved detection rate Screening at 11-20 wks 10 12 14 16 18 20 wks Allows adjustment of age-related risk Improved detection rate Courtesy Dr J Johnson and the Fetal Medicine Foundation

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

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

Gestation 11-14 wks CRL 45-84 mm Mid-sagittal view Image size >75% Nuchal Translucency Gestation 11-14 wks CRL 45-84 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

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

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

First Trimester Biochemical Markers 2- PAPP-A: Pregnancy associated plasma protein A Produced by placental trophoblast Increases in 10-14 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

Fetal NT + Maternal age + ßhCG + PAPP-A at 11-14 wks Screening at 11-14 wks Fetal NT + Maternal age + ßhCG + PAPP-A at 11-14 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

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

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

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

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

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

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

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)

Chorionic Villus Sampling Performed at 10-14 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

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

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

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

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

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

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

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

Post Test List one advantage of CVS over amniocentesis Early results