Dr. Chang T.C.
Obstetrician & Gynaecologist Singapore
MBBS London, MD London, FRCS Glasgow, FRCOG UK, FAMS
If you have been told your pregnancy is high risk, it does not mean that something has already gone wrong. It means that certain factors in your health, your baby’s development, or your pregnancy itself call for a more individualised approach to your care.
A pregnancy may be considered high risk when there is an increased likelihood of complications affecting the mother, the baby, or both. This may relate to your own health and medical conditions, complications that arise during the pregnancy itself, your baby’s growth and development, the placenta, or whether you are carrying more than one baby.
What this means in practice is closer monitoring and a care plan tailored to your specific circumstances. The degree of additional care required will vary from person to person, and many women with a high-risk pregnancy go on to have straightforward deliveries and healthy outcomes.
A high-risk pregnancy in Singapore, as defined internationally, is one where one or more factors increase the chance of complications for the mother, the baby, or both. The degree of additional monitoring and care required will depend on the specific risk factors involved and how your pregnancy progresses.
| Maternal health and medical conditions | Pregnancy-related factors | Fetal factors |
| High blood pressure (hypertension) | Multiple pregnancy (twins, triplets, or more) | Fetal growth concerns |
| Diabetes, whether pre-existing or diagnosed during pregnancy | Previous preterm birth | Suspected structural abnormalities |
| Autoimmune conditions such as lupus or antiphospholipid syndrome (APS) | Previous pregnancy loss | Genetic or chromosomal concerns identified through screening |
| Thyroid disorders or other significant medical conditions | Cervical insufficiency (where the cervix may open too early) | |
| A history of previous pregnancy complications | Placental complications | |
| Advanced maternal age, where clinically relevant |
Certain maternal, placental, and fetal conditions are among the more common reasons women are referred to a high-risk pregnancy specialist in Singapore. Below is an overview of conditions that Dr Chang manages as part of high-risk pregnancy care.
Blood pressure conditions in pregnancy exist on a spectrum.
Left undetected, preeclampsia can progress and affect both maternal and fetal wellbeing. Monitoring during pregnancy may include blood pressure assessment, urine tests for protein, blood tests, and fetal growth surveillance.
Women with pre-existing diabetes, as well as those who develop gestational diabetes (diabetes that arises during pregnancy), may require more careful monitoring. Raised blood glucose levels can affect fetal growth and have implications for the baby’s health after birth.
Management typically involves blood glucose monitoring, dietary guidance, and, in some cases, medication. Additional ultrasound assessments may be recommended to track fetal growth and amniotic fluid levels.
Beyond maternal health conditions, certain placental and fetal factors may also place a pregnancy in the high-risk category and require their own monitoring and management approach.
The placenta plays a central role in your baby’s nourishment and development throughout pregnancy. Certain placental conditions may require closer monitoring and careful planning, particularly as delivery approaches.
Placenta Previa
Placenta previa occurs when the placenta lies partially or completely over the cervix. This can cause bleeding during pregnancy and may affect decisions about how and when delivery is planned. The position of the placenta is monitored through ultrasound as the pregnancy progresses.
Placenta Accreta Spectrum
In placenta accreta, the placenta attaches more deeply into the uterine wall than normal. This condition is more common in women who have had a previous Caesarean section or other uterine surgery. It requires careful monitoring during pregnancy and thorough planning ahead of delivery. When identified early, this condition can be managed with the right preparation and specialist input.
Placental Abruption
Placental abruption occurs when the placenta separates from the uterine wall before delivery. This can cause vaginal bleeding and may affect the oxygen and nutrient supply to the baby. The severity varies, and management depends on the extent of the separation and the gestational age.
Fetal growth restriction occurs when a baby is not growing at the expected rate during pregnancy.
Not every small baby has fetal growth restriction. Some babies are smaller than average but growing normally. Fetal growth restriction refers specifically to a situation where the baby is not reaching its growth potential, often related to a problem with placental function.
When fetal growth restriction is suspected, ongoing monitoring helps assess your baby’s wellbeing and guide decisions about timing and mode of delivery. This monitoring may include serial growth ultrasound scans, amniotic fluid assessment, and Doppler blood-flow studies, which assess circulation in the placenta and your baby’s blood vessels.
The timing and mode of delivery will depend on the severity of the growth restriction, Doppler findings, gestational age, and the overall wellbeing of both mother and baby.
Dr Chang’s research background includes his doctoral thesis on serial ultrasound assessment of the growth-restricted fetus, conducted at University College Hospital, London. This forms part of his broader clinical experience in fetal surveillance and maternal-fetal medicine.
Twin pregnancies and other multiple gestations carry a higher likelihood of complications than singleton pregnancies, including preterm birth and differences in fetal growth between babies. In twins who share a placenta (monochorionic twins), specific placental complications such as Twin-to-Twin Transfusion Syndrome (TTTS) and Twin Anaemia Polycythaemia Sequence (TAPS) may also arise.
The frequency and type of ultrasound monitoring required will depend on whether the twins share a placenta, a sac, or both.
Certain infections acquired during pregnancy may require additional assessment because they can, in some cases, affect fetal development or wellbeing. Examples include cytomegalovirus (CMV), toxoplasmosis, and parvovirus B19.
Depending on the clinical situation, assessment may involve maternal blood tests, ultrasound monitoring, fetal assessment, and diagnostic testing where indicated. Not every infection will affect the pregnancy, but early identification allows your doctor to monitor the situation and act promptly if needed.
If routine screening suggests an increased risk of a chromosomal condition, or if an ultrasound identifies a possible structural abnormality, further investigation may be recommended. A family or medical history of certain conditions may also warrant earlier or more detailed assessment.
Possible next steps may include:
| Assessment | What it involves |
| Detailed fetal anomaly ultrasound | A thorough ultrasound scan to examine your baby’s structure and development in detail |
| Non-Invasive Prenatal Testing (NIPT) | A blood test that screens for chromosomal conditions such as Down’s syndrome, where appropriate |
| Chorionic Villus Sampling (CVS) | A procedure to test a small sample of placental tissue for chromosomal or genetic conditions |
| Amniocentesis | A procedure to test a sample of amniotic fluid for chromosomal abnormalities or, in certain cases, suspected fetal infection |
| Specialist counselling | A consultation to discuss findings, explain options, and support decision-making |
These assessments are part of the prenatal screening services offered at the clinic.
Fetal echocardiography is a specialised ultrasound examination that assesses the structure and function of your baby’s heart in detail. It provides more information than a routine anomaly scan. It may be recommended if any of the following apply to you:
In selected cases, certain fetal conditions may require treatment before birth or referral to a specialist fetal therapy centre.
Depending on the diagnosis, examples of fetal interventions that may be considered include intrauterine blood transfusion for severe fetal anaemia and fetoscopic treatment for selected complications affecting monochorionic twins.
Dr Chang’s role in such cases focuses on assessment, counselling, coordination of care, and referral to the appropriate specialist team where required. The management of complex fetal conditions is always a multidisciplinary process.
Managing a high-risk pregnancy is an ongoing process rather than a one-off intervention. Your care plan is reviewed and adjusted as your pregnancy progresses, based on how you and your baby are doing.
Depending on your risk factors, your monitoring may include:
Ultrasound assessments in a high-risk pregnancy may be more frequent and more detailed than in a routine pregnancy. These may include:
As the pregnancy progresses, additional assessments may be used to evaluate how your baby is doing. These can include:
The tests recommended will depend on your individual circumstances and the risk factors involved. You are unlikely to need all of the following; your obstetrician will recommend the assessments most relevant to your situation:
Test | What it assesses |
Detailed fetal ultrasound and serial growth scans | Your baby’s size, growth rate, and development over time |
Doppler ultrasound | Blood flow in the placenta and your baby’s blood vessels |
Fetal echocardiography | The structure and function of your baby’s heart in detail |
Non-Invasive Prenatal Testing (NIPT) | Chromosomal conditions such as Down’s syndrome, using a maternal blood sample |
Chorionic Villus Sampling (CVS) | Chromosomal or genetic conditions, using a sample of placental tissue |
Amniocentesis | Chromosomal abnormalities or suspected fetal infection, using a sample of amniotic fluid |
Non-Stress Test (NST) | Your baby’s heart rate to check for signs of wellbeing or distress |
Biophysical Profile (BPP) | Your baby’s movements, muscle tone, breathing, amniotic fluid, and heart rate patterns |
When you have a high-risk pregnancy, how and when your baby arrives is something your obstetrician will plan carefully with you.
A number of factors will influence decisions about the timing and mode of delivery, including:
Factor | Why it matters for delivery planning |
Your overall health and any underlying medical conditions | Conditions such as hypertension or diabetes may influence when delivery is safest for you |
Your baby’s growth and wellbeing closer to term | Fetal growth and Doppler findings help guide decisions about the timing of delivery |
Placental position | Placenta previa or accreta may affect whether a vaginal delivery is possible |
Previous Caesarean section or uterine surgery | Prior surgery affects the options available and the risk profile for delivery |
Multiple pregnancy | Twin and higher-order pregnancies often require more detailed delivery planning |
Any other complications arising during the pregnancy | Developments such as preeclampsia or fetal growth restriction may change the plan as you approach term |
It is worth noting that having a high-risk pregnancy does not automatically mean you will need a Caesarean section. Many women with high-risk pregnancies deliver vaginally. Delivery planning is always individualised and will be discussed with you in advance by your high-risk pregnancy gynaecologist in Singapore.
Go to hospital immediately | Contact your obstetrician promptly |
Vaginal bleeding | Persistent severe headaches |
Severe or persistent abdominal pain | Changes in vision, such as blurring or visual disturbances |
Suspected rupture of membranes | Sudden swelling of the face or hands |
Regular painful contractions before 37 weeks of pregnancy | A noticeable reduction in your baby’s movements |
Any other symptoms your obstetrician has advised you to watch for |
Dr TC Chang is a Consultant Obstetrician and Gynaecologist with a special focus in high-risk pregnancy and maternal-fetal medicine spanning more than three decades.
His specialist background includes:
Dr Chang currently sees patients at Thomson Medical Centre and also performs obstetric deliveries and surgical procedures at Mount Elizabeth Novena Hospital.
This depends on your specific risk factors. Women with high-risk pregnancies generally require more frequent ultrasound assessments than those with uncomplicated pregnancies. Some may need growth scans every two to four weeks; the exact schedule will depend on your specific risk factors and how the pregnancy progresses.
Not every small baby has fetal growth restriction. Some babies are smaller than average but growing normally and receiving adequate nutrition through the placenta. Fetal growth restriction refers to a situation where the baby is not reaching its growth potential, often due to a problem with placental function. Distinguishing between the two requires serial ultrasound assessment and, in some cases, Doppler blood-flow studies.
Many placental conditions, such as placenta previa and placenta accreta, can be identified or suspected through ultrasound during pregnancy. This allows for advance planning and, where necessary, early intervention. Regular antenatal care and ultrasound monitoring are important for detecting these conditions.
Not automatically. The mode of delivery is determined by a range of factors, including your medical history, your baby’s position and growth, placental position, and the overall progress of your pregnancy. Many women with high-risk pregnancies deliver vaginally. Delivery planning is discussed with you well in advance.
Fetal echocardiography may be recommended if a possible cardiac abnormality is identified on a routine scan, if there is a relevant family history, or if certain maternal or fetal risk factors are present. It provides a more detailed assessment of your baby’s heart than a standard anomaly scan.
Yes. A high-risk classification means that additional care and monitoring are warranted, not that complications are inevitable. With appropriate management, many women with high-risk pregnancies experience straightforward deliveries and healthy outcomes.
If you have an existing medical condition, a history of pregnancy complications, a multiple pregnancy, or concerns identified during prenatal screening, speaking with an obstetrician early in your pregnancy, or at a pre-pregnancy check-up before you conceive, can help you understand what monitoring and management may be appropriate for your situation.