These were the concluding remarks from a couple whom I counseled regarding antenatal sonographic findings of an extra toe in the left foot and a mild unilateral dilatation of renal pelvis. The couple was concerned that they had done “all possible” genetic testing for the unborn child and their NIPT test was negative. They were anxious and were ready to terminate the pregnancy at 22 weeks of gestation.

After hearing out their concerns and taking a detailed family history, I realized that the family was not at high risk for any particular genetic disorder. The following points were explained to them in a simple language-

1. 1. Every pregnancy is at risk for some genetic disorder. There are about 7000 genetic disorders and there is about 2 - 5 % chance that a pregnancy might be affected with a serious genetic disorder. This risk may be increased for certain genetic disorders if the family or personal history suggests so. A detailed family history analysis may determine that.
   2. Antenatal sonography done at appropriate gestational ages (12 weeks, 16-17 weeks and 19-22 weeks) can rule out major structural abnormalities in the unborn baby with 95% of sensitivity. However, functional abnormality of organs (like deafness or neurological function) can not be determined by sonography
   3. . NIPT or noninvasive prenatal screening test is offered to all pregnant women to determine the “chances” of common genetic disorders in the fetus. This test SCREENS ONLY for 3 common aneuploidies (Trisomy 21, 18 and 13) in the fetus. If the fetus is detected to have significantly higher risk than the background/ predefined risk then the definitive testing (amniocentesis) may be recommended. Importantly, as it is not a definitive test, it does not detect/ screen/ diagnose ALL POSSIBLE genetic disorders.
   4. If sonography is suggestive of any major structural abnormality or family history is suggestive of any specific genetic disorder, in those cases definite invasive testing might be recommended only for a single or a few specific genetic conditions.
   5. I also told them that a mild unilateral pelvis dilations and extra toe in one foot are very commonly observed structural variations in antenatal USG. In majority of the cases, renal pelvis dilatation disappears on its own as the pregnancy advances. Appropriate testing might be suggested if this dilatation increases significantly or amniotic fluid around the baby diminishes.

Initially anxious, the couple started to relax that their baby was after all not at very high risk for serious genetic disorders. Antenatal USG or genomic testing is not perfect but can rule out common abnormalities. Reproductive decisions should be weighed on a delicate balance of perceived risk and scientific facts. There will always be some uncertainties about the pregnancy outcomes and we need to be truthful while speaking to every family