Using Noninvasive Prenatal Testing for Aneuploidies in a Developing Country: Lessons Learnt

Abstract

The objective of the present study was to analyze the utility of noninvasive prenatal testing (NIPT) for aneuploidies in a developing country like India. NIPT was offered to 500 pregnant women, after review of data of the ongoing pregnancy. Pre-test counseling included the different methodologies of testing, their benefits, limitations, turnaround time and interpretation of the result and was offered to all. Different vendors were used for the test. The results were explained in a post-test counseling session. The indications of NIPT were positive second (36.6 %) or first (22 %) trimester screen, advanced maternal age with or without positive biochemical screen (24.6 %), ultrasound soft markers (10.8 %), previous history of Down syndrome (4.6 %) and anxious couple (0.1 %). No aneuploidy was detected in 484 samples. In 1 case, no result was available. Fifteen (3 %) cases showed positive results. These included 8 cases of trisomy 21, 3 cases of trisomy 18, 3 cases of monosomy X, and 1 case of triploidy. Confirmatory testing revealed 6 cases (40 %) to be false positive-1 case of trisomy 21, 1 case of trisomy 18, 3 cases of monosomy X, and 1 case of triploidy. Of 484 cases, 230 have delivered healthy neonates, while the rest have yet to deliver. Four cases had to discontinue pregnancy due to complications in later pregnancy but unrelated to the NIPT results. Noninvasive prenatal test qualifies as an 'advanced' screening test, and requires invasive diagnostic tests for confirmation of the positive results. The pre-and post-test counseling is essential to appropriately explain the limitations, benefits, and the results to the couple. Recommendations are made for the appropriate deployment of this new technology in developing countries.

The Emergence and Global Spread of Noninvasive Prenatal Testing

“…This preference may also be explained by the geographical context: For those living in periurban or rural areas, amniocentesis has the advantage of not requiring them to return to the clinic in case of a high-chance or no-call result (167). However, access to invasive testing is also difficult because of limited numbers of trained medical staff (40).…”

Noninvasive prenatal screening for fetal common sex chromosome aneuploidies from maternal blood

“… 9 The detection rate is much lower in some developing countries if there is not good quality control. 9 – 11 Therefore, screening efficiency is currently unsatisfactory.…”

Current Status of Noninvasive Prenatal Testing and Counselling Considerations: An Indian Perspective

“…Blood samples were collected in Streck tubes and shipped to the USA or China. By June 2014, at Sir Ganga Ram Hospital, we had carried out NIPT in 500 women who mostly had positive contingent screening tests or had soft markers detected on ultrasound studies [35]. Pre-and post-test counselling was offered to all women, explaining that NIPT is a high efficiency screening test, but not a diagnostic test.…”