Intrauterine Growth Restriction (IUGR) in Pregnancy

TL;DR

Intrauterine growth restriction (IUGR), also called fetal growth restriction (FGR), is when a baby in the womb is smaller than expected — an estimated fetal weight below the 10th percentile for its gestational age (Cleveland Clinic) (StatPearls / NCBI). It is usually detected during routine prenatal care through fundal height checks and ultrasound, because it rarely causes symptoms the mother can feel (KidsHealth). Common causes include placental insufficiency, maternal high blood pressure or pre-eclampsia, infections, smoking or alcohol, and carrying twins or triplets (MedlinePlus). There is no medicine that directly "cures" IUGR — management means close monitoring, treating the mother's health conditions, good nutrition, and delivering the baby at the safest time, sometimes early (ACOG). With timely detection and care, most babies with IUGR do well.

Quick Answer

IUGR (intrauterine growth restriction) means the baby's estimated weight is below the 10th percentile for its gestational age. It is caused by problems with the placenta, maternal conditions like high BP or infections, or lifestyle factors like smoking. It is detected by ultrasound and fundal height checks, and managed with close monitoring, treating the underlying cause, healthy nutrition and well-timed delivery — early delivery if the baby is safer outside the womb.

Author: Mylo Editorial Team, Mylo Parenting Desk Medically reviewed by: Mylo Editorial Board, aligned with ACOG and FOGSI guidance Last updated: 3 July 2026

Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. IUGR is diagnosed and managed only by your doctor. If you notice reduced baby movements, bleeding, severe headache, vision changes or swelling, contact your gynaecologist or go to the hospital immediately.

Key Takeaways

• IUGR/FGR = estimated fetal weight below the 10th percentile for gestational age (Cleveland Clinic)
• Two types: asymmetrical (70 to 80% of cases — tummy small, head relatively normal) and symmetrical (20 to 30% — whole body proportionally small) (StatPearls / NCBI)
• Usually NO symptoms the mother can feel — detected at prenatal check-ups (KidsHealth)
• Main causes: placental insufficiency, maternal high BP/pre-eclampsia, infections, smoking, alcohol, multiple pregnancy (MedlinePlus)
• Diagnosis: fundal height measurement, ultrasound, Doppler blood-flow studies, fetal heart monitoring (Cleveland Clinic)
• Management: close surveillance, treating maternal conditions, nutrition, corticosteroids if early delivery is likely, and delivering at the right time (ACOG)
• Not every small baby has IUGR — some babies are simply constitutionally small and healthy (StatPearls / NCBI)
• Never skip prenatal visits — early detection is the single biggest protection

What Is Intrauterine Growth Restriction (IUGR)?

Intrauterine growth restriction (IUGR), also called fetal growth restriction (FGR), is a condition in which a baby does not grow as expected inside the womb. Doctors define it as an estimated fetal weight below the 10th percentile for gestational age — meaning the baby is smaller than 90% of babies at the same week of pregnancy (Cleveland Clinic) (StatPearls / NCBI).

Babies born after growth restriction are often described as "small for gestational age" (SGA). The two terms overlap but are not identical: SGA describes a baby's size at birth, while IUGR describes restricted growth during pregnancy. Importantly, not every small baby is growth-restricted — some are simply constitutionally small and perfectly healthy, which is why doctors interpret size along with blood-flow and fluid tests (StatPearls / NCBI).

IUGR can begin at any stage but is more often picked up in the second half of pregnancy.

What Are the Types of IUGR?

(StatPearls / NCBI) (KidsHealth)

How and When Is IUGR Detected?

IUGR usually causes no symptoms the mother can feel, so it is almost always detected during routine prenatal care (KidsHealth). Tests your doctor may use:

What Causes IUGR in Pregnancy?

The most common underlying problem is that the baby does not receive enough oxygen and nutrients, usually because of an issue with the placenta or umbilical cord (KidsHealth). Contributing factors include (MedlinePlus) (Cleveland Clinic):

In many cases IUGR is multifactorial, and sometimes no single cause is found (ACOG).

What Are the Symptoms of IUGR?

IUGR itself usually has no obvious symptoms for the mother — this is exactly why regular prenatal check-ups matter so much (KidsHealth). Possible signs that lead doctors to check further include:

• The bump (fundal height) measuring small for the week of pregnancy (Cleveland Clinic)
• Reduced baby movements — always report this to your doctor the same day
• Too little (or sometimes abnormal) amniotic fluid on ultrasound (Cleveland Clinic)
• Slower-than-expected growth between two ultrasounds
• Signs of an associated condition such as pre-eclampsia in the mother (high BP, protein in urine, swelling, severe headache)

How Does IUGR Affect the Baby and the Pregnancy?

Timely monitoring greatly reduces risks, but untreated or severe IUGR can lead to complications (Cleveland Clinic) (MedlinePlus):

• Preterm birth: the baby may need to be delivered early, with risks such as breathing difficulty
• Low birth weight: smaller babies are more prone to infections and feeding difficulties
• Difficulty maintaining body temperature and blood sugar after birth
• Low oxygen levels and distress during labour, which may make a caesarean safer
• Stillbirth: in severe, unmonitored cases — this is why surveillance and timely delivery matter (ACOG)
• Associated maternal conditions: IUGR often occurs alongside pre-eclampsia and placental problems such as abruption, so the mother's health is monitored closely too

Most babies with IUGR who are detected on time and delivered at the right moment go on to grow and develop well (MedlinePlus).

How Is IUGR Treated and Managed?

There is no medicine that directly makes a growth-restricted baby grow faster. Management focuses on finding the cause, keeping the baby safe, and choosing the best time and mode of delivery (ACOG):

1. Close Monitoring

Serial ultrasounds to track growth and amniotic fluid, Doppler studies of the umbilical cord blood flow, and regular non-stress tests (Cleveland Clinic).

2. Treating the Mother's Health Conditions

Controlling blood pressure, diabetes or thyroid disease, treating infections, and correcting anaemia and nutritional deficiencies (KidsHealth).

3. Stopping Harmful Exposures

Quitting smoking, alcohol and any recreational drugs immediately — this is one of the most effective steps a mother can take (MedlinePlus).

4. Corticosteroid Injections (If Early Delivery Is Likely)

If the doctor anticipates delivery before about 34 weeks, corticosteroid injections are given to the mother to mature the baby's lungs before birth (StatPearls / NCBI).

5. Rest — With a Caveat

Doctors may advise reducing strenuous activity, but strict bed rest is no longer routinely recommended, as evidence does not show it improves fetal growth — follow your own doctor's personalised advice.

6. Well-Timed Delivery

The safest time depends on how severe the restriction is and how the baby is coping. Depending on the findings, delivery may be planned around 37 to 39 weeks, or earlier if tests show the baby is safer outside the womb. Labour may be induced, and a caesarean section is chosen when the stress of labour would be risky for the baby (StatPearls / NCBI) (ACOG).

What Can I Do If My Baby Has IUGR?

You cannot control everything about IUGR, but you can meaningfully support your baby (KidsHealth):

• Attend every prenatal appointment and scan — monitoring is the treatment
• Eat a balanced diet rich in protein, iron, calcium and calories; take the iron-folic acid and other supplements your doctor prescribes (ICMR Dietary Guidelines)
• Track baby movements daily (kick counts) and report any reduction the same day
• Sleep well and reduce stress; resting on your side improves blood flow to the baby
• Completely avoid tobacco, alcohol and recreational drugs
• Take medicines exactly as prescribed, and never stop a prescribed medicine without asking your doctor
• Discuss the plan for delivery — including the possibility of early delivery — with your gynaecologist in advance
• Seek emotional support from your partner, family or a counsellor; an IUGR diagnosis can be stressful, and support helps

Which Health Conditions Put Me at Higher Risk of IUGR?

Talk to your doctor early if you have any of these (MedlinePlus) (Cleveland Clinic):

• High blood pressure before pregnancy or developing in pregnancy (including pre-eclampsia — high BP with protein in the urine)
• Placental problems in this or a previous pregnancy, or a previous baby with growth restriction
• Heart, kidney or thyroid disease, or diabetes
• Autoimmune disorders such as lupus or antiphospholipid syndrome
• Malnutrition or anaemia
• Smoking or alcohol use during pregnancy
• Infections such as rubella, CMV, syphilis or toxoplasmosis
• Multiple pregnancy (twins, triplets or more)

Consulting your gynaecologist early and regularly is the best way to catch and manage IUGR in time.

Indian Context: What Indian Mothers Should Know

• Anaemia and nutrition: Anaemia and undernutrition are common among Indian pregnant women and are modifiable risk factors — take your iron-folic acid tablets and eat protein- and iron-rich foods like dal, eggs, palak, ragi and dairy (ICMR Dietary Guidelines)
• Regular ANC visits: Fundal height and ultrasound checks at government and private facilities catch IUGR early; schemes like JSY and PMSMA make antenatal check-ups accessible — never skip them
• Growth scans: If your doctor orders a "growth scan" or Doppler in the third trimester, it is a routine, painless ultrasound — not a cause for panic
• Small babies in the family: Relatives may say "babies in our family are just small." Sometimes true — but only your doctor can distinguish a healthy small baby from a growth-restricted one, using Doppler and fluid checks (StatPearls / NCBI)
• Diet myths: No single food (ghee, saffron, coconut) can "increase baby weight" — overall balanced nutrition plus treating the underlying cause is what helps
• FOGSI-aligned care: Indian obstetric practice follows structured protocols for FGR surveillance and delivery timing (FOGSI)

Myths vs Facts About IUGR

FAQs: IUGR in Pregnancy

What is the main cause of IUGR?

The most common cause is placental insufficiency — the placenta not delivering enough oxygen and nutrients to the baby (KidsHealth). Maternal conditions like high blood pressure and pre-eclampsia, infections, smoking, alcohol and multiple pregnancy are other major contributors (MedlinePlus).

IUGR kya hota hai aur kya baby normal ho sakta hai? (Hinglish)

IUGR ka matlab hai ki baby pet mein apni umar (gestational age) ke hisaab se chhota hai — uska estimated weight 10th percentile se kam hai. Iska matlab ye NAHI ki baby normal nahi hoga. Sahi time par diagnosis, regular scans aur doctor ki salah ke mutabik delivery se zyada tar IUGR babies bilkul theek rehte hain aur pehle 1-2 saal mein apni growth catch up kar lete hain. Regular ANC check-up kabhi miss na karein aur baby ki movement roz track karein.

How is IUGR different from "small for gestational age" (SGA)?

IUGR describes restricted growth during pregnancy, while SGA describes a baby's size at birth (below the 10th percentile). Many SGA babies were growth-restricted, but some are simply healthy, constitutionally small babies (StatPearls / NCBI).

Can IUGR be corrected during pregnancy?

There is no medicine that directly speeds up the baby's growth. What helps: treating the mother's conditions (BP, diabetes, anaemia, infections), stopping smoking and alcohol, good nutrition, close monitoring, and delivering the baby at the safest time (ACOG).

IUGR mein kya khana chahiye? (Hinglish)

Koi ek "magic food" nahi hota. Balanced diet lein: dal, eggs, paneer, doodh-dahi (protein aur calcium ke liye), palak-methi, chukandar, gud aur khajoor (iron ke liye), ragi, nuts aur fruits. Doctor ki di hui iron-folic acid aur calcium tablets roz lein. Ghee ya kesar se baby ka weight nahi badhta — poora balanced khana aur underlying problem ka ilaaj hi kaam karta hai. Tobacco, sharab aur bina puche koi bhi dawai bilkul avoid karein (ICMR).

Will I need a C-section if my baby has IUGR?

Not always. Many IUGR babies are delivered vaginally, often after induced labour. A caesarean is recommended when monitoring shows the baby may not tolerate the stress of labour (KidsHealth).

When will an IUGR baby be delivered?

It depends on severity and how the baby is coping. Milder cases are often delivered around 37 to 39 weeks; more severe cases may need earlier delivery, with corticosteroid injections given first to mature the baby's lungs if before about 34 weeks (StatPearls / NCBI).

Do IUGR babies catch up on growth after birth?

Most do. With good feeding, warmth, infection prevention and regular paediatric follow-up, the majority of IUGR babies catch up on growth in the first couple of years (MedlinePlus). Your paediatrician will track weight, length and milestones.

Can IUGR happen again in the next pregnancy?

A previous IUGR pregnancy does increase the risk in the next one, so tell your doctor early. Pre-pregnancy planning — controlling BP and diabetes, correcting anaemia, quitting smoking — plus closer monitoring in the next pregnancy significantly improves outcomes (Cleveland Clinic).

How can I reduce my risk of IUGR?

Start prenatal care early and attend every visit, manage existing conditions before conception, take prescribed supplements, eat a balanced diet, avoid tobacco and alcohol completely, and get screened and vaccinated (e.g., rubella before pregnancy) as advised (MedlinePlus) (ICMR).

References

1. Cleveland Clinic. "Intrauterine Growth Restriction (IUGR)." https://my.clevelandclinic.org/health/diseases/24017-intrauterine-growth-restriction
2. Cleveland Clinic. "Fundal Height." https://my.clevelandclinic.org/health/diagnostics/22294-fundal-height
3. MedlinePlus (U.S. National Library of Medicine). "Intrauterine Growth Restriction." https://medlineplus.gov/ency/article/001500.htm
4. Nemours KidsHealth. "Intrauterine Growth Restriction (IUGR)." https://kidshealth.org/en/parents/iugr.html
5. American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin No. 227: "Fetal Growth Restriction." https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2021/02/fetal-growth-restriction
6. StatPearls, NCBI Bookshelf. "Fetal Growth Restriction." https://www.ncbi.nlm.nih.gov/books/NBK562268/
7. ICMR / NIN. "Dietary Guidelines for Indians." https://www.nin.res.in/dietaryguidelines/pdfjs/locale/DGI07052024P.pdf
8. FOGSI (Federation of Obstetric and Gynaecological Societies of India). https://www.fogsi.org/