Ultrasound and fetal medicine
Also known as Early Pregnancy Scan or Dating Scan. Performed from 6-10 weeks, if you have the scan too soon, it may be that nothing can be seen. 5+ weeks is too soon to have a scan, there will be nothing to see and it could prove upsetting to not hear a heartbeat or see a gestational sac.
Why Have A Pregnancy Viability Scan
Reassurance – If you have previously had a miscarriage, having a viability scan can reassure you that this pregnancy is starting out well. At 6 weeks gestation a heartbeat can be seen and heard and this reduces the likelihood of a miscarriage down to 10%. At 8 weeks gestation, the risk of a miscarriage when a heartbeat is present is reduced to 2%. This is very reassuring. But to have a scan at 6 weeks, your dating must be accurate. If there is no heartbeat, this will be very upsetting but it could simply be that you are a little early and another week would make all the difference.
Dating – If you have an irregular cycle, the actual date of conception might not be easy to calculate and the viability scan will date your pregnancy, giving you an accurate delivery date.
Number of Embryos – Most mums-to-be expect to have one baby at a time, but sometimes nature takes a turn and you may have two or even three gestational sacs. If you have twins or triplets, the care you will need during your pregnancy will change, to ensure that all babies develop normally.
Position of the Gestation Sac – If you have previously had an ectopic pregnancy, this is important to check to ensure that the pregnancy is developing in the uterus and not in the fallopian tube as this is a medical emergency and the pregnancy must be removed before the fallopian tube ruptures.
Gestational Size – If you know that your dates are correct, it is reassuring to check the gestational size is within normal limits. This gives your obstetrician and midwife information about the early development of your pregnancy. The fetal measurement is taken from the top of the baby’s head (the crown) to the baby’s bottom (the rump)-CRL(crown/rump length)
Bleeding – This is a worrying sign in early pregnancy but may not mean that anything is wrong. A viability scan, if bleeding should occur is important, to check that the pregnancy is unaffected and reassure that the bleeding will settle and the pregnancy is ongoing.
Pain – Pain is not usually a feature of early pregnancy, but it does not necessarily mean there is anything wrong. However pain in early pregnancy should be investigated, because it could be a symptom of an ectopic pregnancy and this is a medical emergency. The pregnancy cannot continue if it is not in the body of the uterus.
NT scan with early anomaly assessment
(Combined FTS) NT SCAN + Blood
tests ( 11-14 weeks )
It’s a general conception (rather misconception) that the incidence of chromosomal abnormalities increases with advance maternal age. Traditionally invasive testing like amniocentesis and CVS have been offered to pregnant women aged 35 years or more which can be associated with a risk of miscarriage following an interventional procedure.
Screening by a combination of maternal age, measurement of nuchal translucency and placental products of free Beta HcG and PAPP-A significantly improve the detection rate of common chromosomal abnormalities of up to 90%(5% FPR) thereby avoiding unnecessary fetal invasive procedures in a low risk patient. In addition, it also gives us an opportunity to perform an early anomaly assessment at this gestation to identify structural abnormalities that could be evident in the developing fetus at this stage.
The scan approximately takes about 30 - 45 minutes to perform, and it includes the following.
1. Measurement of the CRL (Crown to rump length) to calculate the estimated due date of
2. Measurement of nuchal translucency
3. Early fetal anomaly assessment
4. Maternal bloods to check levels of Beta HcG, PAPP-A to give a combined risk assessment for the common chromosomal abnormalities (e.g. Down syndrome)
5. Cervical assessment to predict risk of preterm delivery prior to their appointment. There are no other restrictions and they can eat and drink as normal before the scan. The scan results would be available after the procedure; however, the screening results for Down syndrome would be available in 3-5 working days. This report can either be collected in person or can be sent to the patient by email.
TIFFA Scan / Anomaly Scan
A TIFFA Scan (Targeted Imaging For Fetal Anomalies) Scan is popularly known as Fetal Anomaly Scan. It is one of the most important scans conducted during pregnancy because it detects the majority of congenital abnormalities in the growing fetus. This scan is done between 18 - 22 weeks of pregnancy. In this scan, the baby is screened from head to toe to look for abnormalities.
some of the important things a TIFFA scan can tell us are:
Whether the internal organs of the fetus are growing normally.
Monitor the fetal movement.
Detect any birth defects.
Check the level of amniotic fluid.
Any indications of chromosomal abnormalities.
Check the position of the placenta.
Limitation of tiffa scan
Although ultrasound is a useful screening tool for fetal anomalies, the sensitivity of this scan is highly variable and potentially detects only 70% of all fetal anomalies. The ability of this scan to detect structural fetal abnormalities depends on a variety of factors. These factors include the severity of the anomaly, gestational age at the time of the scan, the expertise of the ultrasound technician, and maternal obesity.
Prenatal identification and management of cardiac abnormalities are important since they are the leading cause of infant death and congenital heart disease accounts for 30 to 50% of these deaths.
Fetal echo is recommended for women with a family history or previous child with cardiac
anomalies or if there is raised nuchal translucency measurement in the first trimester, a mother with diabetes. Fetal echo is also recommended if other fetal anomalies are seen in routine or anomaly scans.
Dr. Kv Sree Devi include careful assessment of fetal heart as part of the anomaly scan
assessment. It’s important to be aware that fetal echocardiography is done to exclude major
structural abnormalities in the heart that could alter the outcome of the pregnancy. Minor
anatomical variants such as a small hole in the heart muscle (ventricular septal defect) are not
always possible to be picked up on routine screening and may only be diagnosed after birth.
Once a complex cardiac abnormality is identified, the couple is counseled regarding the scan
findings and the management pathway is discussed. We can also arrange a formal consultation with a specialist pediatric cardiologist / cardiac surgeon if necessary to discuss the management
Specialized fetal echocardiography would take approximately 30-45 minutes to perform and the scan findings will be discussed with the patient after the scan.
Growth and well-being scan with Doppler
This scan is usually offered to pregnant women at later gestation to check for the growth and well-being of the fetus. While most obstetricians offer this scan for all their patients, it is particularly useful in high-risk pregnant women (advanced maternal age, IVF pregnancy, pregnancy complicated by preeclampsia, diabetes to name a few) or if there is a suggestion of intrauterine growth restriction (IUGR, or FGR) during the pregnancy.
This scan usually takes 15-30 minutes to perform and it involves
1. Measurement of fetal biometry (head, abdomen, femur) to calculate the estimated fetal weight for the gestation
2. Assessment of placenta and amniotic fluid volume
3. Assessment of fetal movements during the scan
4. Doppler blood flow assessment of placenta and the fetus
The results will be given to the patient after the scan.