If you are a non – medico and would like to read the articles in simple language, without medical terms, please visit ‘IM Healthy’.


Small-for-Gestational-Age (SGA) Fetus for MRCOG

ImbibeMe / ImbibeMedMRCOG Part 2Module 2 – Antenatal care /Small-for-Gestational-Age (SGA) Fetus for MRCOG.

Share this Article

Risk Factors for Small-for-Gestational-Age (SGA) Fetus

Major Risk Factors Minor Risk Factors
Maternal age > 40 years.
Maternal age > 35 years
Smokers >/= 11 cigarettes per day
Smokers 1-10 cigarettes per day
Daily vigorous exercise
Low fruit intake pre - pregnancy
Previous SGA baby
Previous Pre - eclampsia
Previous stillbirth
Pregnancy interval < 6 months or > 60 months
Maternal SGA
BMI < 20
Chronic Hypertension
IVF Singleton pregnancy
Diabetes with vascular disease
Mild PIH
Renal impairment
Heavy bleeding similar to menses
Antiphospholipid syndrome
Caffeine > 300 mg/day in third trimester
Placental abruption
Fetal echogenic bowel
Pre - eclampsia
Severe PIH
Unexplained APH
Low maternal weight gain
PAPP-A < 0.4 MoM

Management of Small-for-Gestational-Age (SGA) Fetus


Prediction of Small-for-Gestational-Age (SGA) Fetus

Abdominal palpation – Limited accuracy for the prediction of SGA.

Serial measurement of symphysio – fundal height (SFH) – Recommended at each antenatal appointment from 24 weeks of pregnancy as this improves prediction of a SGA neonate.

Routine fetal biometry for prediction of SGA fetus is not justified.

Investigations in a Small-for-Gestational-Age (SGA) Fetus

  1. In severe SGA fetus :-
    • If severe SGA identified at the 18 – 20 weeks scan ⇒ Detailed anatomic survey + Uterine artery Doppler by a fetal medicine specialist.
    • In severe SGA fetuses with structural anomalies (detected before 23 weeks of gestation, especially if uterine artery Doppler is normal ⇒ Karyotyping.
    • Serological screening for Cytomegalovirus (CMV) and Toxoplasmosis.

2. In high risk populations ⇒ Syphilis and Malaria.

Interventions to prevent Small-for-Gestational-Age (SGA) Fetuses/neonates

Antiplatelet agents may be effective in preventing SGA birth in women at high risk of pre – eclampsia.

In women at high risk of pre-eclampsia, antiplatelet agents should be commenced at, or before, 16 weeks of pregnancy.

Interventions to promote smoking situation may prevent delivery of a SGA infant.

There is no consistent evidence that dietary modification, progesterone or calcium prevent birth of a SGA infant.

Interventions for Preterm SGA

Women with a SGA fetus between 24 + 0 and 35 + 6 weeks of gestation, where delivery is being considered, should receive a single course of antenatal steroids.

Other investigations in SGA

CTG should NOT used as the only form of surveillance in SGA fetuses.

Interpretation of the CTG should be based on short term fetal heart rate variation from computerised analysis.

USG assessment of Amniotic Fluid Volume – should NOT be used as the only form in SGA fetuses.

Interpretation of amniotic fluid volume should be based on single deepest vertical pocket. 

Biophysical profile should not be used for fetal surveillance in preterm SGA fetuses.

Consider supporting us

Consider buying us a book if this article has helped you in anyway.  We shall be delighted and thankful.

Further Reading

Green Top Guideline No. 31 – The Investigation and Management of
the Small–for–Gestational–Age Fetus.

Important Links

Shop Related Products


Share this Article

How useful was this post?

Click on a star to rate it!

Average rating 5 / 5. Vote count: 2

No votes so far! Be the first to rate this post.

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?