For first-time mothers in Jhansi, the sequence of pregnancy scans can feel confusing. Different doctors mention different scans at different times, and it can be difficult to understand what each one is looking for, why it is done at that particular stage, and what happens if something needs a closer look. At Jhansi Diagnostics & Fetal Medicine Centre, Dr Furquan Ahmad, MBBS MD, believes that a mother who understands what each scan is designed to do is a mother who can engage meaningfully with her own pregnancy care rather than simply going through the motions. The more you know about each scan before you have it, the more prepared you are for whatever it shows.
Here is a complete guide to every pregnancy scan from week 6 to week 36 and what each one is designed to find.
Week 6 to 8: The Early Viability Scan
The earliest pregnancy scan is the viability scan, sometimes called the dating scan or the early scan. It is typically performed between 6 and 8 weeks of pregnancy, usually requested when there has been bleeding or pain, when the patient has a history of ectopic pregnancy or miscarriage, or simply to confirm the pregnancy is progressing normally before the first routine antenatal appointment.
At this stage the baby is tiny, measuring just a few millimetres, but the most important finding the scan looks for is a heartbeat. Confirming a fetal heartbeat at 6 to 7 weeks is the most reassuring sign that the pregnancy is viable and developing as expected. The scan also confirms that the pregnancy is inside the uterus rather than in the fallopian tube, which would indicate an ectopic pregnancy requiring urgent medical attention.
The gestational age is calculated at this scan by measuring the crown-rump length, the distance from the top of the baby’s head to its bottom. This measurement is most accurate in the first trimester and gives a reliable estimated due date. If the gestational age calculated from the scan differs significantly from the date based on the last menstrual period, the scan measurement takes precedence for pregnancy dating. You can find out more about early pregnancy scanning services at Jhansi Diagnostics & Fetal Medicine Centre on the ultrasound page.
Week 11 to 14: The NT Scan and First Trimester Combined Screening
The nuchal translucency scan is one of the most important scans in the first trimester and needs to be performed within a narrow window between 11 weeks and 13 weeks 6 days. Beyond 14 weeks the nuchal translucency measurement is no longer valid.
Dr Furquan Ahmad measures the fluid-filled space at the back of the baby’s neck, the nuchal translucency, and combines this measurement with the results of the double marker blood test and the mother’s age to calculate a personalised risk figure for Down syndrome, Edwards syndrome, and Patau syndrome. This combined first trimester screening gives a far more accurate risk assessment than maternal age alone.
Alongside the NT measurement, Dr Furquan Ahmad also assesses the nasal bone, the blood flow through the ductus venosus, and the tricuspid valve at the same appointment where the technology allows, as these additional markers further refine the risk calculation. The baby’s overall anatomy is also reviewed at this stage, though a detailed structural assessment is not possible until the anomaly scan at 18 to 20 weeks.
The NT scan also confirms the number of babies, establishes whether twins share a placenta or have separate placentas, which determines their monitoring schedule for the remainder of the pregnancy, and recalculates the gestational age if the earlier dating scan was not performed. The fetal medicine page has more detail on first trimester fetal medicine services at the centre.
Week 18 to 20: The Anomaly Scan
The anomaly scan is the most detailed structural assessment of the baby available during pregnancy and is an essential part of antenatal care for every expecting mother regardless of age or risk status. It is performed between 18 and 22 weeks, with 18 to 20 weeks being the optimal window.
Dr Furquan Ahmad systematically examines every major structure of the baby during the anomaly scan at Jhansi Diagnostics & Fetal Medicine Centre. The brain, including the cerebellum, ventricles, and corpus callosum. The face, including the upper lip for cleft detection. The spine from cervical to sacral level. The heart, including all four chambers and both outflow tracts using Colour Doppler. The lungs, diaphragm, stomach, abdominal wall, liver, kidneys, and bladder. The limbs, including bone length measurements. The umbilical cord insertion at the abdomen.
Alongside the fetal anatomy, the anomaly scan assesses the placental position, which is important for identifying placenta previa. The amniotic fluid volume is measured. The baby’s growth is assessed through biometric measurements including head circumference, abdominal circumference, femur length, and estimated fetal weight, all compared against standard charts for the gestational age.
Soft markers, as discussed separately, are assessed and documented during the anomaly scan and interpreted in the context of the patient’s combined screening results. Any finding that needs further assessment is discussed with the patient before they leave. The FAQs page at the centre answers common questions about anomaly scan preparation and findings.
Week 20 to 24: Uterine Artery Doppler for High-Risk Pregnancies
For women in higher-risk categories, a uterine artery Doppler assessment is recommended between 20 and 24 weeks. This specialised Doppler study assesses blood flow resistance in the uterine arteries, which supply blood to the placenta from the mother’s side.
Abnormal uterine artery Doppler waveforms at this stage are associated with an increased risk of developing pre-eclampsia and fetal growth restriction later in the pregnancy. Identifying this risk early allows monitoring to be intensified before problems become apparent on standard growth scans. Women with hypertension, a previous pregnancy complicated by pre-eclampsia or growth restriction, or other vascular risk factors benefit most from this assessment.
Week 28 to 32: Growth Scan and Doppler Assessment
By the third trimester, the focus of scanning shifts from structural assessment to growth monitoring and fetal wellbeing. A growth scan between 28 and 32 weeks measures the baby’s head circumference, abdominal circumference, femur length, and estimated fetal weight and plots these against standard growth charts to assess whether the baby is growing at the expected rate.
Doppler studies are performed alongside the growth scan for higher-risk pregnancies. The umbilical artery Doppler assesses placental blood flow resistance. The middle cerebral artery Doppler assesses whether the baby is redirecting blood to protect its brain, a sign of stress. Amniotic fluid volume is measured as part of the overall fetal wellbeing assessment.
For low-risk pregnancies with no previous concerns, a single growth scan in this window combined with standard antenatal monitoring is often sufficient. For higher-risk pregnancies, including those with growth restriction, hypertension, diabetes, or a previous stillbirth, more frequent growth and Doppler monitoring throughout the third trimester is standard practice at Jhansi Diagnostics & Fetal Medicine Centre.
Week 32 to 36: Presentation Scan, Growth Monitoring, and Delivery Planning
In the final weeks before delivery, scans serve several purposes. Growth monitoring continues with repeat biometric measurements to track the baby’s weight gain in the third trimester, when the baby gains approximately 200 grams per week. The placental position is reassessed for any patient who had a low-lying placenta identified on the anomaly scan, to confirm whether it has moved away from the cervix or whether caesarean section planning is needed.
The baby’s presentation, meaning whether the baby is head-down, breech, or transverse, is confirmed at this stage. Most babies settle into a head-down position by 34 to 36 weeks, but those who remain breech may require an external cephalic version procedure or a planned caesarean section. Knowing the baby’s position in advance allows delivery planning to happen calmly rather than as an emergency decision.
For high-risk pregnancies, biophysical profile assessment may also be incorporated into the monitoring schedule at this stage, combining growth measurements, Doppler studies, amniotic fluid assessment, and observation of fetal movements and breathing to give a comprehensive picture of fetal wellbeing in the final weeks before delivery. You can explore the full range of pregnancy scanning and monitoring services at the centre on the our services page.
Between Scheduled Scans: When to Come in Without Waiting
Understanding the scheduled scan timeline is important, but equally important is knowing when not to wait for the next scheduled appointment. Any reduction in fetal movements after 24 weeks should be reported and assessed the same day. Any vaginal bleeding during pregnancy warrants prompt evaluation. Any symptoms of pre-eclampsia, including severe headache, visual disturbances, upper abdominal pain, or sudden significant swelling of the face, hands, and feet, require immediate medical attention.
At Jhansi Diagnostics & Fetal Medicine Centre, Dr Furquan Ahmad accommodates urgent scan requests for patients with concerns between scheduled appointments. You can reach the team through the contact us page or book an appointment through the booking appointment page. You can also read more about Dr Furquan Ahmad and the centre’s approach to pregnancy care on the about us page.
Every scan in this sequence is a chapter in the story of your baby’s development. Understanding what each chapter is looking for helps you follow that story with confidence rather than anxiety.
