The first Prenatal Visit

1
The first Prenatal Visit

• Maeve OBeirne

2
The first visit

• Establish pregnancy
• Establish dates
• Order prenatal bloodwork
• Counsel about genetic screening
• Other tests

3
Establish pregnancy

• Home pregnancy test positive
• Clinic pregnancy test positive

4
Establish dates

• Woman good historian and sure of LMP
• EDD adjusted for length of cycle
• Ultrasound
• Question
• What is the EDC for a woman with a LMP March 20,
  cycle length 32 days

5
Prenatal Bloodwork

• Most listed on the prenatal record
• Need to add ferritin
• TSH if history of thyroid disease in patient,
  consider if in family
• Early diabetic screen if insulin dependent in
  previous pregnancies
• 2 forms required
• CLS (CBC, ferritin, TSH, diabetic screen)
• Prov lab (rubella, varicella, HIV, HepB,
  syphilis, ABO/Rh, antibody screen)

6
Other Tests

• PAP
• Look for and document friable cervix
• Swabs or urine (chlamydia, gonorrhea)
• Consider
• Toxoplasmosis
• CMV
• Parvovirus

7
Questions?

• SAMP 3

8
SAMP 3

• Genevieve is a 27 year old at 10 weeks gestation
  coming for her first prenatal visit at your
  clinic. Her LNMP was June 4. Her cycle length
  is 24 days. She has had 4 previous pregnancies,
  2 miscarraiges, one set of twins that were born
  at 32 weeks and one full term infant.

9
SAMP 3

• What is Genevieves EDC? Please show your
  calculation.
• To LNMP subtract 3 months, add 7 days.
• Short Cycle so need to adjust by subtracting 4
  days.
• March 7
• What is her gravida and para status?
• G5P2

10
SAMP 3

• What routine blood work would you order at this
  visit? List seven.
• - Hb
• - MCV
• - plt
• - ABO
• - Rh status
• - Blood antibodies
• - Hepatitis B
• - Rubella
• - Syphilis
• - HIV
• - Varicella

11
SAMP 3

• List 3 foods that this woman should avoid during
  pregnancy?
• Shellfish
• Deli meats
• Unpasturised cheeses
• Unpasturised milk, juices or ciders
• Raw sprouts
• Raw meat or fish
• Herbal teas (some)
• Alcohol
• Artificial sweeteners (some)

12
SAMP 3

• What important lifestyle topics should be
  discussed at this visit? List 5.
• Smoking status Marital stress
• EtOH use Domestic violence
• Illicit drug use Nutrition
• Genetic screening Safe medications
• Occupational exposure Exercise
• Financial stress HIV testing

13
Genetic Screening

• All women should be offered genetic screening
• Few will actually want the screening
• NT (11-136 weeks gestation)
• Triple screen (15-17 weeks)

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Counseling for Genetic Screening

• What will be done with the result
• Will they terminate
• Will they worry throughout the pregnancy
• Would a high needs child fit in their life

15
Genetic Screening

• Screening test, not diagnostic
• Does not tell patient for sure that infant is
  normal
• If positive will be offered amniocentesis
• 1/200 risk of miscarraige
• Designed so that 7-10 positive

16
Risks of Genetic Screening

• Psychological
• If screen comes back positive
• Pregnancy loss
• If they choose to have amnio

17
Risks of Downs Syndrome
18
Nuchal Translucency

• 12-136 weeks
• Ultrasound
• Looks at thickness of Nuchal fold
• Alone detects 70 of aneuploidy
• With addition of bloodwork detection rate
  improves

19
NT and Bloodwork

• Human chorionic gonadotropin (hCG) is increased
  and pregnancy associated plasma protein A
  (PAPP-A) is decreased in Downs syndrome.
• Can detect approx 90 Downs Syndrome with a 5
  false positive rate

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Nuchal Translucency

• Advantages
• Done early
• Is an ultrasound
• Psychologically reassuring
• Dating done at same time
• Disadvantages
• Does not asses risk of NTD
• Operator skill dependant
• Not available in all centres
• Skills within centres variable

21
Triple Screen

• 15-16 1/2 weeks
• Blood test on pregnant woman
• AFP BHCG estriol
• Will detect 85 NTD, 60-70 aneuploidy

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Triple Screen

• Advantages
• NTD as well as aneuploidy
• More readily available
• Disadvantages
• Performed late
• Affected by race, weight, diabetes
• Abnormal in IVF
• Dates must be accurate

23
NT Triple Screen

• Not recommended in Alberta
• Not sure how to interpret the results when one is
  positive and the other negative

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Amniocentesis

• The diagnostic test
• Miscarriage rate of 1/200
• Can be offered to womengt40 at time of birth
• Will be offered to those with a positive screen

25
Common problems in the first trimester

• Hyperemesis
• Vaginal bleeding
• Missed abortion
• Rh negative

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Questions?

• SAMP 1

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SAMP 1

• Causes of NV
• NV of pregnancy
• Heartburn
• Dyspepsia
• Thyroid
• diabetes
• Lifestyle modifications
• Small frequent meals
• No spicy or citrus foods
• Rest
• Smelly foods
• Lots of fluids
• Split liquids and solids

28
SAMP 1

• Investigations if symptoms severe
• CBC, lytes, TSH, BUN, Creat, urinalysis, U/S
• Medications
• Diclectin (up to 6 pills per day-delayed action)
• Maxeran (10mg q6h)
• Gravol (50mg q6h)
• Zofran
• Phenergran
• Largactil
• Stemitil

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The 18 week Ultrasound

• Obstetrical Sonography The Best Way to Terrify
  a Pregnant Woman
• Roy A. Filly, M.D.

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The 18 week Ultrasound

• SOGC recommendation
• Advantages
• Dating
• Placental position
• Detects multiples
• Anatomical survey of fetus
• Disadvantages
• Genetic markers

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Genetic Markers

• Choroid plexus cysts
• Echogenic intracardiac foci
• mild pyelectasis
• echogenic bowel
• Shortened long bones (humerus)
• Others

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Choroid Plexus Cysts

• Found in 2 of normal pregnancies
• Cysts disappear spontaneously during pregnancy
  and are, in themselves, of no concern before or
  after birth
• No need to re-scan during pregnancy
• Children with choroid plexus cysts are
  developmentally normal and indistinguishable from
  those in whom no cysts were seen on ultrasound
  examination during pregnancy

33
CPCs

• Increased risk of Trisomy 18
• isolated finding in women lt35 yrs, risk for
  trisomy 18 lt 1
• Need to look at other risk factors
• Maternal age, FHx, TSS, NT
• Fetal anatomical scan
• cyst size, bilaterality, shape, and persistence
  do not help in determining fetal karyotype or
  outcome
• 1997 study found no association of CPC and Down
  syndrome for patients with no other risk factors

34
CPCs

• Is genetic amniocentesis warranted when isolated
  choroid plexus cysts are found?Gray DL, Winborn
  RC, Suessen TL, Crane JP.Department of
  Obstetrics and Gynecology, Washington University
  School of Medicine, St Louis, Missouri, USA.Our
  aim was to evaluate the prevalence of trisomy 18
  in the setting of isolated fetal choroid plexus
  cysts and then to consider the risk of trisomy 18
  versus the risks of genetic amniocentesis.
  Fetuses with choroid plexus cysts were
  prospectively obtained from a total mid-trimester
  population of 18861 fetuses with known outcomes.
  If the fetuses had trisomy 18, they were part of
  the study group and part of the control group if
  they had normal karyotypes. 208/18861 (1.1 per
  cent) fetuses had choroid plexus cysts. 201/208
  (96.6 per cent) were normal fetuses or newborns,
  while 7/208 (3.4 per cent) of the fetuses with
  choroid plexus cysts had trisomy 18. Overall, 16
  fetuses had trisomy 18 and seven (44 per cent) of
  these had choroid plexus cysts. 0/16 fetuses had
  choroid plexus cysts as the only sonographic
  finding. Cysts gt or 10 mm were more often
  associated with trisomy 18 than with a normal
  karyotype (P lt 0.01). We conclude that the
  discovery of choroid plexus cysts in otherwise
  normal fetuses in the late second trimester does
  not by itself justify the risks of genetic
  amniocentesis.

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Trisomy 18

• Hydrocephalus
• neural tube defect 
• cystic hygroma
• overlapping fingers 
• rocker bottom feet    
• ventricular septal defects
• Micrognathia
• club feet  
• fisted hands
• Diaphragmatic hernia            
• omphalocoele  
• severe growth restriction

36
Intracardiac echogenic focus

• 5-10 of pregnancies
• Higher in Asian population
• Associated with Trisomy 21 and 13
• Study of 3303 fetuses, RR in low risk population
  4.2 for trisomy 21
• Latest study RR 1.0 with no other markers

37
EIF

• An Isolated Echogenic Heart Focus Is Not an
  Indication for Amniocentesis in 12,672 Unselected
  Patients
• Claudio Coco, MD, Philippe Jeanty, MD, PhD and
  Cerine Jeanty
• Department of Ultrasound, Womans Health
  Alliance, Nashville, Tennessee USA.
• Objective. To evaluate the risk of Down syndrome
  in fetuses with a heart echogenic focus. Methods.
  We prospectively evaluated 12,672
  second-trimester sonographic features and
  extracted and examined a population with an EIF
  for chromosomal anomalies. Results. 479 cases of
  EIF 90.4 were isolated, 9.6 had associated
  findings. 11 patients had fetuses with trisomy
  21. 8 of those did not have an EIF, whereas 3 had
  a EIF. Only 1 fetus with trisomy 21 had an
  isolated EIF. The positive likelihood ratio for
  total cases of a heart EIF and trisomy 21 was
  7.25, whereas for an isolated EIF, the positive
  likelihood ratio was 2.66. Conclusions. The risk
  of aneuploidy is increased in fetuses with an
  EIF however, the finding should prompt a
  detailed structural survey and correlation with a
  priori risk. Amniocentesis need not be offered to
  patients who are otherwise at low risk and have
  an isolated EIF.

38
Trisomy 21

• nasal hypoplasia,
• increased nuchal fold thickness,
• cardiac defects,
• duodenal atresia
• mild hydronephrosis,
• shortening of the femur and more so of the
  humerus,
• sandal gap and clinodactyly or mid-phalanx
  hypoplasia of the fifth finger.

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Trisomy 13

• holoprosencephaly,
• microcephaly,
• facial abnormalities,
• cardiac and renal abnormalities with often
  enlarged and
• echogenic kidneys,
• exomphalos
• post axial polydactyly

40
Echogenic Bowel

• 1 of pregnancies
• Associated with cystic fibrosis (1-13),
  intrauterine growth restriction, premature birth,
  cytomegalovirus infection (1-10), stillbirth,
  Downs Syndrome

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Mild Pyelectasis

• 2 of pregnancies
• More common in males
• Associated with Downs Syndrome
• mild pyelectasis and a normal karyotype
• risk for urinary tract problems

43
Shortened Long Bones

• Associated with trisomy 21
• Not common finding

44
Questions?

• SAMP 2

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SAMP 2

• Marley is a 34 year old G2P1 at 11 weeks
  gestation. Her last pregnancy was 3 years ago
  and was uncomplicated. She had an SVD of a 3.5kg
  female infant. She is healthy.

46
SAMP 2

• What genetic screening options would you discuss
  with her? List 3.
• Nuchal Translucency
• Combined first trimester screening
• Triple screen
• Amniocentesis
• CVS
• Integrated prenatal screening
• Integrated biochemical serum screening
• What is her approximate risk for carrying a fetus
  with Down Syndrome?
• 1/385

47
SAMP 2

• What does a positive screen mean?
• That the risk of the fetus having a chromosomal
  abnormality is greater than that of a 35 year old
  woman. It does not mean that the fetus is
  abnormal unless either CVS or amnio has been
  done.
• Who is eligible for an amniocentesis in Canada.
  List 3
• -Woman over 40 years of age at the time of
  delivery
• -History of a previous pregnancy affected by
  genetic disorder or NTD
• -A family history of a genetic disorder
• -A positive screen
• -Have had an ultrasound with a finding
  suggestive of an increased risk.
• What are the risks of amniocentesis? List 2
• -Miscarriage, Leaking fluid, Infection, cramping

48
Hypothyroid in Pregnancy

• 2007 CPGs Journal of Clinical Endocrinology and
  Metabolism
• No evidence for screening all women
• Increased MC, preterm delivery, decreased
  intelligence
• If hypothyroid before pregnancy adjust so that
  TSHlt2.5
• T4 dose usually needs to be incremented by 4-6wks
  gestation and may require a 30-50 increase in
  dose
• If diagnosed during pregnancy, TSH should be
  brought to lt2.5 ASAP and kept there.
• Subclinical hypothyroid should be treated to
  reduce TSH to lt2.5
• Most hypothyroid women will required a decrease
  in dose after delivery

49
Hyperthyroid in Pregnancy

• Associated with hyperemesis
• Subclinical hyperthyroidism does not require
  therapy
• Propylthiouracil first line therapy
• Presence of antibodies associated with increased
  MC
• In antibody positive women need serial fetal U/S