Mrs. Neha [Name changed] was referred to our genetic OPD at 32 weeks of pregnancy with her antenatal USG showing left sided diaphragmatic hernia. Fetal liver and intestines were pushed in thoracic cavity and lungs were appearing hypoplastic. The pregnancy was also complicated by mild Rh Isoimmunisation. Previous antenatal scans were reported to be normal. The couple was extremely anxious and they wanted to know:

1) Why was the abnormality not detected in previous scans?
2) Is it possible to “terminate the pregnancy” now?
3) What will be the outcome of the baby if they decide to deliver the baby?

Congenital Diaphragmatic Hernia [CDH] is a major developmental malformation with a prevalence of 1-4:10,000 live births. Majority of the cases can be identified in 18-24 weeks antenatal scans. However, rarely, the diagnosis of CDH, may first time be apparent after 24 weeks in cases of small defect, absence of abdominal organs herniation into the thoracic cavity and diaphragmatic eventration, which is a close differential of CDH. This fact answers their first question, that not diagnosing CDH in earlier gestation age was not a negligence by the health practitioner who had performed previous antenatal USG.

About their second question, Indian MTP law allows families to discontinue of pregnancy upto 24 weeks of pregnancy. However, if a serious abnormality is detected after 24 weeks, the family may seek assistance from a medical board [available in Pune and Mumbai]. However in this case, pregnancy was already at 32 weeks, if delivery was attempted at this gestational age, there was a good chance, that baby would be born live. At that point of time, the family would have to take take decision of either treating the baby or removing all life support.

Third question- CDH can be treated by postnatal surgery and a satisfactory outcome may be expected in 30-50% cases. However the outcome depends a lot on gestational age at delivery, birth weight, size of the defect and degree of lung hypoplasia. Moreover, about 30-40% of CDH cases may have associated genetic aberrations, which may worsen the prognosis. This pregnancy was very advanced for performing any fetal genetic evaluation. At few selected centres in developed countries, pregnant couple have an option of prenatal therapy in antenatally detected CDH. In these cases, by an open hysterotomy, between 26- 30 weeks of gestation, a ballon is inserted into fetal trachea. The balloon has to be removed at around 33-34 weeks. This balloon allows the accumulation of fluid in fetal lungs and their expansion, and hence reducing the chances of subsequent lung hypoplasia.The babies still need surgery after delivery. This procedure is associated with high fetal and maternal morbidity.

Though I could empathise with decisional and emotional dilemma faced by family, as a geneticist, I could just support them in any decision they would take and provide the best plan of management in that context. After considering all the options, the family decided to continue the pregnancy, work-up the baby after birth and give him/her a complete chances of a successful life. The pregnancy is currently 34 weeks and is being planning for Caesarian section with a team of pediatrician and paediatric surgery on standby.

This case highlights a usual day in a life of Medical Geneticist. The counseling had to be factual, non directive and yet empathetic. Many a times, no decision is completely right or wrong, but we have to support the family in whatever decision they take.