Case based Discussion on Early on-set FGR
Samrakshan is a National Initiative of the Indian Radiological and Imaging Association (IRIA) that addresses safe motherhood and issues related to fetal growth and pregnant women in India. Fetal Growth Restriction (FGR) or suboptimal growth of the fetus is a major problem in India with short and long-term consequences on health. Samrakshan conducted a National Fetal Growth Restriction Awareness Week 2022 jointly organized by IRIA Preventive Radiology and IRIA Kerala in association with Journo Med and MedPiper Technologies. These were a series of educational webinars that discussed clinical practice based on actual clinical cases.
The second educational webinar focused on the theme of Early on-set fetal growth restriction (FGR) and utilized a case-based discussion pedagogical approach.
Dr Kavitha Aneja, MD a senior Radiologist from Rohini, New Delhi gave a detailed view on early-onset fetal growth restriction (FGR) illustrating various aspects through actual clinical cases.
Ms Shilpa Satarkar is the National Coordinator for the Samrakshan project of our Indian Radiology and Imaging Association (IRIA) for 2022-23. The main task is to sensitize all the radiologists regarding pre-eclampsia (PE) and fetal growth restriction screening (FGR) in the first trimester and the use of colour doppler in all the growth scans and thereby integrating early screening of the patient and start with prophylactic treatment and to identify the patients with early fetal growth restriction (FGR). Overall, the aim is to reduce perinatal mortality in India. Two aspects were discussed.
- To perform the pre-eclampsia (PE) and the fetal growth screening (FGR) in the first trimester.
- Fetal Doppler studies are integrated with the second-trimester growth scans, to identify growth-restricted fetuses and to help with more optimal monitoring of this high-risk group for timely delivery thereby reducing perinatal mortality.
Dr Praveen Nirmalan, Chief Research Mentor, Samrakshan India, briefly introduced fetal growth restriction (FGR). He explained that each person and fetus has individualized growth potential and the growth patterns differ from one individual to another. Every human starts its growth as a fetus; the growth patterns of the fetus can affect growth later in life. He emphasized that we must remember that we were once a fetus and our growth as a fetus has contributed to our current standing as an adult humans. He said if we reflect on this, we can bring a personal connection to the problem of fetal growth restriction.
Dr Kavitha Aneja, a Fetal Radiologist from New Delhi gave a detailed view on case-based learning on early-onset fetal growth restriction (FGR) and was the moderator for the webinar. The importance of biometry, assessment of congenital anomalies and genetic abnormalities, associated comorbidities and patient characteristics were highlighted.
Dr Sakshi, a fetal medicine consultant and genetician from Mohali gave an insight that the patient’s maternal history needs to be monitored until they get delivered. In the case of pre-eclampsia with issues of chronic hypertension, low-dose aspirin must be recommended during the patient’s early visits. Low-dose aspirin helps in preventing the progression of pre-eclampsia.
Early on-set FGR
Early-onset FGR commences before 32 weeks and late-onset FGR commences after 32 weeks. However, it is an arbitrary cut-off, and there is a lot of overlap between the weeks.
SOLITARY FEATURES IN THE ABSENCE OF CONGENITAL ANOMALIES:
- Abdominal circumference (AC) or Estimated Fetal Weight (EFW) is less than 3rd centile. So, AC alone or weight alone is less than 3rd centile classifies the fetus as growth restricted.
- Fetal growth restriction (FGR) is defined as the inability to achieve very hypothetical growth potential, it is not possible to accurately predict the growth potential of an individual. Although the abdominal circumference (AC) and weight less than the 3rd centile alone qualify for FGR an umbilical artery absence of diastolic flow is considered as a solitary criterion if the AC/ EFW is less than the the10th centile. Additionally, a
- Uterine artery PI more than 95th centile is also a sign of impending danger.
- The Middle Cerebral Artery Doppler PI less than 5th centile is also an important parameter to assess as it provides information on the brain sparring effect.
In a few cases, the umbilical artery is absent in diastolic flow, and MCA was less than 1 centile, which leads to the Brain sparing effect. The ductus venosus was high showcasing the high resistance with a forward flow.
Dr Sakshi revealed her views regarding the patient’s centile dopplers, classification of fetal growth restriction (FGR), and monitoring of babies at different stages after post-delivery.
Classification of FGR by Barcelona Protocol
Grade 1: There is a very less or low estimated fetal weight (EFW) (< p3 or mild placental) resistance/ redistribution which is observed as CPR value < 5th centile, Uterine artery > 95th centile, MCA < 5th centile. The umbilical artery at this point may be normal.
Grade 2: Severe placental resistance/ redistribution where there is absent end diastolic flow, or reversal or very high resistance of aortic isthmus i.e., 95th centile and this condition is late hypoxia.
Grade 3: Severe hemodynamic adaptation- Low suspicion acidosis where ductus venosus is greater than 95 centile, the umbilical artery has a reverse end diastolic flow, and the condition is termed as Early acidosis.
Grade 4: High suspicion of acidosis- High risk of death- A reversal flow of ductus venosus is observed, CGT declarations of reduced short-term variability. This stage is late acidosis with reduced cardiac compliance. So, stage 1 and stage 2 are early hypoxia and late hypoxia, and stage 3 and stage 4 are early and late acidosis respectively.
Babies monitoring at different stages post delivery
If one discusses the monitoring of these babies, stage 1 is monitored weekly till at around 37 weeks and labour can be induced in these women.
In stage 2, there are monitored twice weekly for up to 34 weeks and require a cesarean section.
In stage 3, the babies are monitored every two days, delivered at or after 30 weeks and need a cesarean section.
In stage 4, where the CTG abnormalities come in, the babies should be monitored daily and delivered at or after 26 weeks and need a cesarean section.
Dr Kiran discussed the conventional CTG and short-term variability. Probably such patients require a hospital set up for continuous monitoring as a loss to follow-up is high.
Treatment options for patients with early FGR
- The patient is advised for a 3-day doppler test when present in a hospital set up and also one can approach conventional CTG where the decelerations and the accelerations can be monitored in a CTG Record. Conventional CTGs don’t provide exact variability as computerized CTGs provide more exact results. CTGs calculate pulse interval and short-term variability.
- When the baby’s condition is hypoxic, conventional CTGs are taken into consideration. The chances of baby survival are less and sometimes it might lead to complications in delivery. The mother must be subjected to absolute rest and requires immediate monitoring.
- If the patient has severe pre-eclampsia or hypertension with super-imposed pre-eclampsia, the chances of the baby surviving are less, and the mother may face cerebral oedema at any point in time. So, these patients need immediate monitoring.
- Fetal indication is another issue. However, the mother’s health remains crucial. So besides monitoring the mother, the fetus should be monitored longitudinally with both ductus venosus and CTG.
- Looking at the umbilical artery study and doppler study, the centile readings of ductus venosus are monitored. It decides whether the women are under FGR Stage 2 or FGR Stage 3.
- Most doctors suggest magnesium sulphate and steroids for lung maturity and neuroprotection.
Dr Lavleen Kaur Sodhi, a gynaecologist from Mohali addressed the significance of magnesium sulphate and steroids during the pre-eclampsia and FGR condition. If the patient is under ongoing impending eclampsia. Magnesium sulphate can protect the mother and prevent the mother from pre-eclampsia.
Essential points on Early on-set FGR
- In early FGR, resistant to hypoxia, there are respiratory centres and cardiovascular centres, where the brain stem is resistant to hypoxia and the CTG and fetal heart rate remain normal. So, delivery is based on umbilical artery reversal or abnormal ductus venosus. Here, CTG serves as a safety net indicator.
- On the early onset of FGR, the placental dysfunction happens early, more than 30 per cent of the placenta which remains dysfunctional. At this time, in the early weeks, the fetal nutritional demand is huge. The fetal smallness is the crucial feature that one sees in the early onset FGR. At this time, the respiratory demand is very low, on early onset FGR. Since the placenta has high resistance, the heart functions against this resistance and the heart have to work hard to pump blood through the umbilical artery into the high-resistance placenta, leading to heart failure. There is a cardiovascular adaptation which is seen in the form of abnormal doppler, which guides delivery in early onset FGR.
- Birth Asphyxia is an important condition to monitor.
- Dr Sandhya Dhankhar, a Fetal Radiologist from Chandigarh highlighted the crucial thing which went missing in most of the pregnancy cases during the first trimester is Aspirin Dosage.
Aspirin- A Wonder Drug
Aspirin is a Wonder Drug that delays the development or onset of pre-eclampsia and is given till the onset of pre-eclampsia, 36 weeks or childbirth, whichever is earlier.
The pregnancy needs to be followed up more closely. Proper counselling helps the patient to land up for treatment in early onset FGR and IUGR.
Note: If the umbilical artery IUGR starts early, It is severe enough to mandate delivery. So, if the umbilical artery becomes abnormal before 26 weeks, the delivery should happen by 30 weeks. This message should be put across to the patient.
In the case when the patient is subjected to delivery at stage 3 FGR i.e., within 30 weeks, there is no point in waiting further for the delivery confirmation as it might lead to further complications and ductus venosus reversal would be the case if further delayed.
Dr Poonam Sidana, a neonatologist from CK Birla Hospital, New Delhi briefly gave an implication on the survival rate and long-term implications. Dr Poonam also gave a clear idea regarding the mortality rate of the patient at 26 weeks, 26-28 weeks and 28-30 weeks. The prognosis of these babies can be known while treatment. If the patients are delivered in the stage 3 FGR at 26 weeks. The survival rate of these babies is less leading to long-term implications and the prognosis of babies can be determined.
A lot of centres show good survival rates of 70-80%. The babies are monitored with cranial ultrasounds, checked for acidosis, and provided neurodevelopmental supportive care and occupational therapy later in life. Care for the early onset growth-restricted fetus needs a multidisciplinary approach involving fetal radiologists, obstetricians, neonatologists, geneticists, paediatricians, and occupational therapists later in life.