Rate of Miscarriage Following Chorionic Villus Sampling on 315 for Prenatal Diagnosis of ThalassemiaRate of Miscarriage Following Chorionic Villus Sampling on 315 for Prenatal Diagnosis of Thalassemia in Kolkata in Kolkata Sujoy DasguptaSujoy Dasgupta11, Kanchan Mukherjee, Kanchan Mukherjee22, Kalyansree Chaudhuri, Kalyansree Chaudhuri33

1 Senior Resident, Chittaranjan National Cancer Institute (CNCI), Kolkata2 Corresponding Author (mukherjee.kanchan@gmail.com)3 Assistant Professor, Burdwan Medical College, Burdwan

INTRODUCTIONINTRODUCTION

• Thalassaemia- Most common congenital haemolytic anaemia in India

• Every year 10,000 thalassaemic babies are born in India

• Huge socio-economic burden • Only way of prevention- Prenatal diagnosis• Chorionic Villus Sampling (CVS) provides early

prenatal diagnosis• Commonest indication of CVS in India- Prenatal

diagnosis of Thalassaemia1

AIMS AND OBJECTIVESAIMS AND OBJECTIVES• To assess the miscarriage rates following

transabdominal CVS for women carrying singleton pregnancy

• To assess other complications,if any

• To assess its effect on pregnancy outcome with special reference to congenital anomalies

MATERIALS AND METHODSMATERIALS AND METHODSSETTINGSETTINGA diagnostic centre in Kolkata

STUDY PERIODSTUDY PERIOD 2 years (Aug 2011- Jul 2013)

STUDY DESIGNSTUDY DESIGNRetrospective Longitudinal Study

INCLUSION CRITERIAINCLUSION CRITERIA

Previous baby affected with Thalassaemia MajorBoth parents Thalassaemia carriers

EXCLUSION CRITERIAEXCLUSION CRITERIAMultiple pregnancy, Bleeding diathesis & Gestation > 20 weeks

STUDY METHODOLOGYSTUDY METHODOLOGYWritten Informed Consent from all participants

Trans-abdominal CVS under direct US guidance with local anaesthesia taking strict aseptic precautions

by a single operator

Discharged immediately with broad spectrum antibiotics for 5 days

Direct Questionnaire at >3 months post-procedure revaginal loss, miscarriage, fetal affection,

preterm labour, limb reduction and missed diagnosis

RESULTSRESULTS

0 50 100 150 200 250 300 350

Total No of CVS Performed

CVS for Thalassaemia

Nos Lost in Follow Up

Number of Women Followed Up

Total Number of CVS

320315

56259

Number of Women

Demographic Variables (n = 315)Demographic Variables (n = 315)

Procedural details (n = 315)Procedural details (n = 315)

Mean + SDAge (yrs) 25.2 + 1.7 Parity 1.3 + 0.7Gestational Age (wks) 12.4 + 2.8

No of Punctures

Single 313 99.37%Double 2 0.63%

PlacentaAnterior 153 48.57%Posterior/ Lateral 162 51.43%

Blood Group

Positive 306 97.14%Negative 09 2.86%

INDICATIONS OF CVS ( n- 315)

26484%

5116%

Previous baby Thal Major

No previous H/O Thal Major baby (parents Thal carrier)

RESULTS OF CVS (n= 259)

Thal major53

20%

Thal trait58

22%

Normal14858%

0 1 2 3

Miscarriage (0.39%)

Leakage of Liquor (0.78%)

Preterm Labour (0.78%)

Congenital Anomaly (Nil)

COMPLICATIONS OF CVS (n= 259)

122

Number of Women

OUTCOME OF PREGNANCY (n= 259)

531

185

20Termination due to Thal affected baby (20%)

Miscarriage (0.4%)- within 6 days of CVS

Delivery of Live Baby (71%)

Continuing pregnancy >24 wk(7%)

0 20 40 60 80 100 120 140 160 180 200

Total No of Delivery

Baby Not living (1%)

Thal Status Checked (40%)

Thal Status Not Checked (58%)

POST-DELIVERY STATUS (n= 185)

185

2

75

108

Corroboration of postnatal Hb Electrophoresis with CVS results- 75/75 = 100%

DiscussionDiscussion

• Most common indication of CVS in our study is prenatal diagnosis of thalassemia- similar to studies by Choudry et al, 20122

• Sampling success rate was 100% in our study (99.7% as per Williams J 3rd et al, 1992)3

• In 99.37% cases, there was single needle insertion, consistent with other studies3

• Fetal loss rate in our study was 0.32%, matches with data published in the literature (0.7%-1.65%)1,4,5

• The low miscarriage rate is explained by the theory that placenta is a spongy organ, capable of easy expansion after the procedure, allowing early healing6

• Minor complications (like leakage of fluid) occurred in 0.64% cases consistent with other studies1

• No congenital anomaly was reported in our cohort

ConclusionsConclusions

• CVS has the advantage of making early prenatal diagnosis of hereditary haemolytic anaemia

• Allows the option of early termination of pregnancy if required

• The procedure is simple, safe, low cost and can be done at the ultrasonography clinic without inpatient admission

ReferencesReferences

1. Laksanavilai U, Piyamongkol W, Sirichotiyakul S, Tongprasert F, Leuwan S, Srisupundit K. Chorionic villous sampling: experience of 636 cases. J Med Assoc Thai. 2013 Apr;96(4):383-8

2. Choudry A, Masood S, Ahmed S. Feasibility and safety of transabdominal Chorionic Villus Sampling. J Ayub Med Coll Abbottabad. 2012 Jan-Mar;24(1):38-43

3. Williams J 3rd, Wang BB, Rubin CH, Aiken-Hunting D. Chorionic villus sampling: experience with 3016 cases performed by a single operator. Obstet Gynecol. 1992 Dec;80(6):1023-9

4. Mujezinovic F, Alfirevic Z. Procedure-related complications of amniocentesis and chorionic villous sampling: a systematic review. Obstet Gynecol. 2007 Sep;110(3):687-94

5. Scott F, Peters H, Boogert T, Robertson R, Anderson J, McLennan A, Kesby G, Edelman D. The loss rates for invasive prenatal testing in a specialised obstetric ultrasound practice. Aust N Z J Obstet Gynaecol. 2002 Feb;42(1):55-8

6. Dhaifalah I, Zapletalova J. Safety and risks associated with screening for chromosomal abnormalities during pregnancy. Ceska Gynekol. 2012 Jun;77(3):236-41

7. Gogate S. Methods of fetal tissue sampling and prenatal diagnosis. In Pai HR, ed. Manual of Genetics and Fetal Medicine. Mumbai: Genetics and Fetal Medicine Committee FOGSI, 2006:22

8. Schaap AH, van der Pol HG, Boer K, Leschot NJ, Wolf H. Long-term follow-up of infants after transcervical chorionic villus sampling and after amniocentesis to compare congenital abnormalities and health status. Prenat Diagn. 2002 Jul;22(7):598-604

ABSTRACT

Rate of miscarriage following chorionic villus sampling on 315 for prenatal diagnosis of Thalassemia in Kolkata

Sujoy Dasgupta, Kanchan Mukherjee, Kalyansree Chaudhuri

Introduction: Approximately 10000 babies are born with Thalassemia in India every year. Prenatal diagnosis of Thalassemia is the commonest indication for Chorionic Villus Sampling (CVS) in India. The primary objective of this study was to assess the miscarriage rates following transabdominal CVS for women with Thalassemia trait carrying singleton pregnancy.

Methods: A retrospective longitudinal study was carried out at a diagnostic centre in Kolkata. Informed consents were obtained from all patients for transabodiminal CVS under direct ultrasonic guidance with local anaesthesia. All procedures were done by the same operator at the same clinic in two years between Aug 2011 and Jul 2013. The median gestation at the time of CVS was 12 weeks. All but two required single puncture. Patients were discharged immediately after the procedure on broad spectrum andibiotics for five days. Outcome data regarding vaginal loss, miscarriage, fetal affection, preterm labour, limb reduction and missed diagnosis were collected by direct questionnaire.

Results: A total of 320 CVS were performed over two years. Five cases were excluded as the indications were different. Three of them were for Spinal Muscular Atrophy (SMA) and one each for Haemophilia and Sickle Cell Anaemia. 56 women were lost in follow up for various reasons. Other 259 women could be followed up, out of which 53 had already terminated pregnancy as their fetuses were shown to be affected by Thalassemia major. Out of the remaining 206 women, 185 have already delivered healthy babies and another 20 have crossed 24 weeks gestation but they are yet to deliver. There was one case of miscarriage which happened 6 days after the procedure.

Conclusion: CVS has the advantage of making early prenatal diagnosis of hereditary haemolytic anaemia. This allows the option of early termination of pregnancy if required. The procedure is simple, safe, low cost and can be done at the ultrasonography clinic without inpatient admission. Our results especially the rate of miscarriage is consistent with the data published in the world literature.