diagnosis modalities of preganancy:obg

1. Diagnosis modalities of
pregnancy

2. DIAGNOSTIC MODALITIES OF
PREGNANCY
• Introduction:
• Many changes occur in woman’s body during pregnancy. These
changes although most apparent in the reproductive organs, involve
other body systems as well.
• Weeks may pass before the family realizes she has become pregnant
or she may learn upon a visit to a doctor for other reasons
• Confirmation of her pregnancy is most important for the health &
welfare of herself & the baby. In this lesson, we will cover the tests used
to determine pregnancy

4. Risk Approach Screening:
• Blood testing
• Excessive weight gain of the mother due to fluid retention. Falling
weight also poses risk as there can be intrauterine growth
retardation.
• Pre-existing hypertension or PIH
• Excess amount or decreased amount of amniotic fluid is another
risk factor.
• Other approaches, which should be followed for high-risk cases,
are: non-invasive & invasive methods are used

6. Non - Invasive
Methods:
• Examination of the woman’s uterus from outside the baby.
• Listening to the fetal heart sound
• External fetal monitoring
• It includes:
• 1) Ultrasonography
2) Non Stress Test
3) Contraction Stress Test (CST)
4) Amniotic Fluid Index (AFI)
5) Cardiotocography

7. Invasive Methods:
1.Chorionic villus sampling
2. Amniocentesis
3. Fetoscopy
4. MSAFP: Maternal Serum Alpha Feto Protein.
5. Cordocentesis
6. Amnioscopy.

8. Objectives of Invasive & Non - Invasive:
• Diagnosis:
• To reduce maternal and fetal mortality rate.
• To check fetal growth and development.
• To enable timely medical or surgical treatment of a condition before or after
birth
• To give the parents the chance to abort a fetus with the diagnosed
condition
• To give parents the chance to "prepare" psychologically, socially,
financially, and medically for a baby with a health problem or disability, or
for the likelihood of a stillbirth

9. Non - Invasive
Methods:
1. ULTRASONOGRAPHY (USG)
• An ultrasonography is a diagnostic technique, which uses high-frequency
sound waves to create an image of the internal organs.
• A screening ultrasound is sometimes done during the course of a
pregnancy to check normal fetal growth and verify the due date.
• It is a safe , non invasive, accurate and cost effective investigation
• Hard tissues such as bone appear white on the image and soft tissues
appear grey.

11. USG Indications:
• In the first trimester:
• To establish the dates of a pregnancy
• To determine the number of fetuses and identify placental structures
• To diagnose an ectopic pregnancy or miscarriage
• To examine the uterus and other pelvic anatomy
• In some cases to detect fetal abnormalities as anencephaly

12. Mid - Trimester:
• To determine the number of fetuses and examine the placental structures
• To assist in prenatal tests such as an amniocentesis, Cordocentesis .
• To examine the fetal anatomy for presence of abnormalities
• To check the amount of amniotic fluid by measuring AFI.
• To examine blood flow patterns
• To check on the location of placenta; to see if its covering cervix
• To observe fetal behavior and activity

13. Third Trimester:
• To monitor fetal growth, to check IUGR
• Detailed anatomical survey.
• To check the amount of amniotic fluid
• to determine the position of a fetus
• To assess the placenta

14. Types of ultrasounds performed during
pregnancy
• Abdominal ultrasound
• Transvaginal ultrasound

15. Abdominal ultrasound:
• In an abdominal ultrasound, gel is applied to the abdomen and the
ultrasound transducer glides over the gel on the abdomen to create
the image

16. Procedure:
Trans Abdominal USG:
• Explain the procedure to the patient.
• Provide privacy
• Provide supine position to the patient.
• Apply gel

17. Nursing responsibility before procedure:
• Explain the purpose of procedure and how it will be done.
• Advise for drink lots of water so that full bladder to capture clearer
images
• Provide privacy.
• Provide supine position (dorsal position).
• The abdominal wall is prepared and draped.
• Check USG

18. Transvaginal Ultrasound:
• A smaller ultrasound transducer is inserted into the vagina and
rests against the back of the vagina to create an image.
• A transvaginal ultrasound produces a sharper image and is often
used in early pregnancy.

19. Indication of Transvaginal ultrasound:
• Early month of pregnancy
• In this high frequency of sound waves used so greater resolution is
possible
• Typical gynaecological indication includes uterine size, evaluation of
endometrium, myometrium, cervix.

20. The confirmation of lung maturation is done to minimize the chances of respiratory
distress syndrome of the baby. In this test, specifically we are looking for
• Lecithin: Sphingomyelin ratio and identification of phosphatidyl glycerol.
• Fetal movement count- In the later pregnancy, fetal well-being is assessed by having
the fetal movement count.
• In Cardif 'count 10' formula, the patient is told to count the 10 fetal movements,
starting from a particular time. She should report to the physician, if she feels less
than 10 movements in 12 hours, on two consecutive days.
• In Daily fetal movement count (DFMC), mother is told to count the fetal movements
for one hour, three times a day (say, morning, afternoon and evening). Later, the total
count is multiplied by 4, which gives DFMC. Mother should report if she feels less than
10 movements in 12 hours.

21. Contraindication:
• Allergy to latex.
• Vaginal infection

22. PROCEDURE
• A probe is placed into the vagina instead of over the abdomen.
• Provide dorsal lithotomy position with empty bladder.
• Vaginal probe should be lubricated with gel and the probe should be
inserted into an appropriate covering sheeth such as condom
• The sheath covered probe is gently advanced up the vaginal canal
• If ultrasound is done before the week 11, it would be transvaginal

23. Safety of USG:
• Ultrasounds bring no long term or short-term harm to both mother
and baby.
• In fact, it is a useful scanning tool. Because the waves are of very
low intensity, there is no danger in repeating the scans, if your
condition merits it.
• However if pregnancy is normal, then 2 routine scans as part of
antenatal care.
• More scans are only necessary if any medical condition

24. 2. NON - STRESS TEST
• Definition:
• A nonstress test (NST) is a screening test used in pregnancy to
assess fetal status by means of the fetal heart rate and its
responsiveness.

26. Purpose:
• To assess the fetal wellbeing
• To measure the heart rate in response to its own movements
Concept of NST:
• Oxygen is required for fetal activity and heart rate to be with in
normal ranges.
Time to Perform NST:
• After 28 weeks of gestation.
• Between 38-42 weeks.
• As early as beginning of third trimester.

27. Indications
:
1.Post dated mothers
2.GDM
3.IUGR
4.Placental and cord abnormalities
5.Absence of fetal movements
6. As a precaution

28. Non - Stress Test:
Findings depends upon the following components:
1.Fetal Heart rate
2.Fetal movement
Fetal Heart Rate Ranges
• Normal Baseline FHR 110–160 bpm
• Moderate bradycardia 100–109 bpm
• Moderate tachycardia 161–180 bpm
• Abnormal bradycardia < 100 bpm
• Abnormal tachycardia > 180 bpm

30. Interpretation
Reactive - Atleast 2 fetal
movements in 20 min
with acceleration of FHR
reacting a peak of atleast
15 Bpm (Beats Per
Minute)
Non - Reactive - No fetal
movements or no
acceleration of heart rate
Uncertain - Fewer fetal
movements or
acceleration less than 15
Bpm

32. Non -
Stress
Test:
Advantages:
• Non invasive.
• Painless.
• Lack of risk to mother and fetus.
• immediate results

33. Disadvantages:
• False positive results during fetal sleep.
• 40 min gives most sleeping fetus time to awaken.
• Awaiting acceleration prolong

34. 3. CONTRACTION STRESS TESTS
• CST is done to see whether fetus remains healthy during reduced
oxygen levels (contraction).
• Definition:
• CST or oxytocin challenge test evaluates FHR in the presence of
spontaneous or oxytocin-induced contractions.

36. Purpose:
• To assess fetal placental functioning.
• Fetus ability to cope up with continuation of high risk pregnancy
and stress of labor

37. Indications:
a) In abnormal biophysical profile.
b) Gives better picture of your baby than NST
c) Contractions , fetal breathing movements, fetal muscle tone, and AFI
can be checked.
• Risks:
• False positive results
• Prolonged contractions
• Labor starts before EDD

38. Sl.no Steps
Rationale
1. Take client to prenatal testing unit. Ensures that qualified personnel
conducts test.
2. Explain the client the procedure. Gain co-operation.
3. Position the client in semi-fowlers
position.
Eliminates
supine
hypotension.
4. Place client on an external monitor.
An USG to record FHR and CTG
for contractions

39. 5. Record client BP initially and at 5-
10 min intervals.
To determine supine hypotension.
6. Obtain atleast 10 min base line
recording (FHR AND contractions)
To test fetal well being.
7. Prepare and begin oxytocin
infusion.
a)start oxytocin infusion.
b)client is evaluated by physician
when dose is 10 mu/mt
Can discontinue the infusion in
hyperstimulation.
To test adequate uterine contractions
and FHR.

40. • Advantages:
• Follow up of non reactive NST.
• More informative.
• Disadvantages:
• Contra-indicated in placenta praevia,LSCS,PROM.
• Utero placental perfusion reduced due to hyperstimulation.
• Time consuming.

41. 4. AMNIOTIC FLUID INDEX
• Amniotic fluid index (AFI) is a rough estimate of the amount of
amniotic fluid and is an index for the fetal well-being.
• AFI is the score (expressed in cm) given to the amount of amniotic
fluid seen on pregnant uterus and calculated by a ultrasonograph (
ultrasound).
• To determine the AFI, doctors may use a four-quadrant technique ,
when the deepest, unobstructed, vertical length of each pocket of fluid
is measured in each quadrant and then added up to the others , or the
so called "Single Deepest Pocket" technique.

43. Method to evaluate amniotic fluid volume:
• Most popular method to evaluate amniotic fluid volume is four quadrant
technique to calculate Amniotic Fluid Index (AFI).
• AFI is obtained by measuring the vertical diameter of largest pocket of amniotic
fluid in 4 quadrants of uterus by USG and the sum of the result is AFI
• AFI :
• <5cm - Oligohydromnios
• 5 - 10cm - Decreased amniotic fluid volume
• 10 - 19cm - Nomal
• 20 - 25cm - Increased amniotic fluid volume
• >25cm - Polyhydromnios

44. Cardiotocography:

45. 5. Cardiotocography:
• Introduction:
• Cardiotocography (CTG) is a test
used in pregnancy to monitor both
the fetal heart pattern as well as
the uterine contractions.
• It should only used in the 3rd
trimester when fetal neural
reflexes are present.
• Its purpose is to monitor fetal well-
being & allows early detection of
fetal distress antenatal or intra-
partum.

46. Difference Between NST & CTG:
• A Nonstress test (NST) is a screening test used in pregnancy to
assess fetal status by means of the fetal heart rate and its
responsiveness.
• A Cardiotocograph (CTG) is used to monitor the fetal heart rate and
presence or absence of uterine contractions.

47. Indications for CTG:
Maternal indications Fetal indications
A. Maternal medical disorders:
1.Pregnancy induced hypertension
2.Diabetes mellitus
3.Anemia and other hematolog.dis.
4.Chronic hypertension
5.Cardiac disease
6.Collagen disease
7.Renal disease
8.Thyroid disease
B. Bad obstetric history
C. Post-date pregancy
1. Reduced fetal movements
2. Suspected IUGR
3. Abnormal FHR by auscultation
4. Multiple pregnancy
5. Rhesus iso-immunisation
6. Before induction

48. Parts of CTG:
It involves the placement of 2 transducers on the abdomen of a
pregnant woman:
• one transducer records the fetal heart rate using ultrasound beam ,
• the other transducer records uterine contractions

49. • Findings depends upon the following components
1. Baseline fetal heart rate
2. Baseline variability
3. Accelerations
4. Decelerations

50. Baseline fetal heart rate:
• The mean level of the FHR when this is stable, excluding accelerations
and decelerations. It is determined over a time period of 5 or 10 minutes
and expressed in bpm.
Baseline variability:
• The minor fluctuations in baseline FHR occurring at three to five
• Cycles per minute. It is measured by estimating the difference in beats
per minute between the highest peak and lowest trough of
fluctuation in a one-minute segment of the trace

51. Decelerations:
1.Early: Head compression
2.Late : Utero-Placental Insufficiency
3.Variable: Cord compression and Primary CNS dysfunction

52. Interpretation:
• Negative:No late deceleration with adequate contractions
• Positive : late deceleration with adequate contractions
• Equivocal :No positive or negative window occurs Hyper stimulation
• Excessive uterine activity is present in association with deceleration of
FHR
• Unsatisfactory: Inadequate FHR record or contractions. Test should be
repeated with in 24 hours

53. • Tachycardia:
• Hypoxia
• Chorioamnionitis
• Maternal fever
• B-Mimetic drugs
• Fetal anaemia,
• Sepsis
• Heart Failure
• Arrhythmias

54. Categorization of fetal heart rate traces:
Category Definition
Normal All four reassuring
Suspicious 1 non-reassuring
Rest reassuring
Pathological 2 or more non-reassuring
1 or more abnormal

55. Suspicious CTG:
CTG Pattern Cause Clinical Management
Early 2nd stage None
Late Uterine hypercontractily Stop oxytocin
Consider terbutaline sc
Oxygen @ 8-10 l/min
Left lateral decubitus
Variable Cord compression Consider amnioinfusion
(mild/mod v.d.)
Tachycardia Maternal
fever,tachycardia,dehydration
Infection screen
Hydrate - crystalloids
Stop tocolysis if pulse>120

56. Invasive methods
1. Maternal Alpha-Fetop protein
2.Amniocentesis
3.Chorionic Villus Sampling (CVS)
4.Cordocenthesis or Percutaneous Umblical cord Blood sampling
5.(PUBS) Fetoscopy
6.Amnioscopy

57. 1. Maternal Alpha - Fetoprotein Screening
(MAFP):
• A blood test that measures the level of alpha- fetoprotein in the
mothers' blood during pregnancy.
• AFP is a fetal protein normally produced by the fetal liver and is
present in the fluid surrounding the fetus (amniotic fluid), and
crosses the placenta into the mother's blood.
• The AFP blood test is also called MSAFP (maternal serum
AFP)Maternal Alpha-Fetoprotein screening (MAFP)

58. All pregnant women are usually offered the AFP test. But, the doctor may
recommend the test, especially if :
• Mother is 35 or older
• Have a family history of birth defects
• Have diabetes
• Have taken certain drugs or medication during pregnancy
• Time of performing test:- 15-18 weeks

59. Abnormal levels of AFP may signal the following:
MSAFP level high indicates:
1. Open neural tube defects (ONTD) such as spina bifida
2. Other chromosomal abnormalities lead to IUFD
3. Defects in the abdominal wall of the fetus
4. Twins more than one fetus is making the protein
5. A miscalculated due date
6. Renal anomalies.

60. • Down’s syndrome
• Gestational trophoblastic disease

61. 2. Amniocentesis:
• It is a medical procedure used in prenatal diagnosis of
chromosomal abnormalities and fetal infections.
• In which a small amount of amniotic fluid, which contains fetal
tissues, is extracted from the amniotic sac surrounding a
developing fetus , and the fetal DNA is examined for genetic
abnormalities.

62. Amniocentesis:
Definition: It is deliberate puncture
of the fluid sac per abdomen.
Indication :- Diagnostic Early and
later therapeutic procedure
Time of performing:
• It is performed between the 15th-
20th weeks of pregnancy.
• Mostly during the 18th week.

63. Contraindication:
• Acute skin infections near the site of needle placement.
• Maternal fever
• Allergies to material used like skin preparation materials, local
anesthesia.
• May be difficulty in-patient with multiple pregnancies

64. Amniocentesis:
Maternal complication
• Infection
• Allo immunisation of the mother
• Preterm labor and delivery
• Hemorrhage
Fetal complication
• Miscarriage
• Respiratory distress,
• Postural deformities
• Fetal trauma.
• Oligo hydramnions due to
leakage of Amniotic fluid

65. Nursing responsibility before procedure:
• Before procedure, take written consent.
• Explain the purpose of procedure
• Emptying the bladder AND Provide privacy.
• Provide supine position with elevated head

66. • The abdominal wall is prepared aseptically and draped.
• Check the vital sign and FHR to obtain base line data.
• Check USG.
• Prophylactic administration of 100 mg of anti –D immunoglobulin in
Rh negative mother.
• The proposed site of puncture is unfiltered with 2 ml of 1%
lignocainE

67. Nursing responsibility after procedure:
• Fetus should be monitored for short period after procedure, check
FHR every 30 minutes.
• Tell patient, to report physician if uterine cramping, vaginal bleeding
or leakage of fluid or fever.
• Strenuous activities should be avoided for 24 hours following an
amniocentesis

68. Chorionic Villus Sampling CVS:

69. 3. Chorionic Villus Sampling CVS:
• Chorionic villous sampling a form of prenatal diagnosis to determine
chromosomal or genetic disorders in the fetus .
• It entails getting a sample of the chorionic villus (placental tissue) and
testing it.
• It can be performed in a transvaginally or transabdominal manner
• Performing time: Before 15 weeks, usually performed between the
10th and 12th weeks of pregnancy.

70. Indications:
• Abnormal first trimester screen results
• Increased AFP or other abnormal
ultrasound findings
• Family history of a chromosomal
abnormality or other genetic disorder
• Parents are known carriers for a genetic
disorder
• maternal age above 35
Contraindication:
• Active vaginal bleeding
• Infection
• Multiple gestation
• HIV infection

71. Complications:
• Miscarriage in CVS in about 0.5 - 1%.
• Infection and amniotic fluid leakage. The resulting amniotic fluid leak can
develop into a condition known as oligohydramnions
• Mild risk of Limb Reduction Defects associated with CVS, especially if the
procedure is carried out in earlier terms (before 12th week of pregnancy).
• Fetal loss.
• Infection
• Vaginal bleeding

72. Nursing responsibility after procedure:
• Fetus should be monitored for short period after procedure, check FHR every
30 minutes.
• Tell patient, to report physician if uterine cramping, vaginal bleeding or
leakage of fluid or fever.
• Strenuous activities should be avoided for 24 hours following a CVS.
• Anti –D immunoglobulin 50 ug IM should be administered following the
procedures to the Rh negative women’s

73. 4. Cordocentesis or Percutaneous Umbilical
Cord:
• Blood Sampling (PUBS):
• It is a diagnostic genetic test that examines
blood from the fetal umbilical cord to detect
fetal abnormalities.
• PUBS provides a means of rapid chromosome
analysis and is useful when information cannot
be obtained through amniocentesis, CVS, or
ultrasound
• Time of performance:-18 weeks of gestation

74. Cordocentesis:
Procedure:
• PUBS is similar to amniocentesis, but instead of sampling the amniotic fluid which surrounds the fetus,
PUBS examines fetal blood
• Before the start of the procedure, a local anesthetic is given to the mother.
• After the local is in effect, a 25 gauze spinal needle 13 cm in length is usually inserted through the
mother's abdominal wall
• An advanced imaging ultrasound determines the location for needle insertion, and the needle is guided
through the mother's abdomen and uterine wall into the fetal vein of the umbilical cord, approximately 1-
2 cm from the placenta.
• The sample can then be sent for chromosomal analysis.

75. Complications:
• Miscarriage is the primary risk associated with PUBS
• Blood loss at the puncture site,
• Infection, and
• Premature rupture of membranes.
• During the procedure, the mother may feel discomfort similar to a menstrual
cramp.
• Cord hematoma formation
• Preterm labor

76. 5. Fetoscopy:

77. 5. Fetoscopy:
• A fibreoptic instrument that can be passed
through the abdomen of a pregnant woman
to enable examination of the fetus and
withdrawal of blood for sampling in prenatal
diagnosis.
• Definition: Examination of the pregnant
uterus by means of a fiber-optic tube.
• Time of performing: 18th week of
pregnancy.

78. Complication:
• Miscarriage, as high as 12%.
• Excessive bleeding, infection, or excessive leakage of the amniotic
fluid.
• Preterm rupture of the membranes which may require early
delivery of your baby .
• Mixing your blood with babys blood

79. 6. Amnioscopy:
Definition:
• Direct observation of the foetus
and the colour and amount of the
amniotic fluid by means of a
specially designed endoscope
inserted through the uterine
cervix. Contraindication
• Cervix is in insufficiently dilated

80. Amnioscopy:

81. Complication:
• Sepsis
• Rupture of membrane