ACOG guidance on fetal growth restriction

IUGR, or intrauterine growth restriction, is now often called fetal growth restriction. It means a fetus may not be reaching its growth potential. It is different from being constitutionally small: some small fetuses are healthy, while growth restriction can reflect placental, fetal, or maternal factors.

A growth scan estimates fetal size from several ultrasound measurements and compares change over time. Clinicians may assess amniotic fluid and use Doppler ultrasound to examine blood flow, particularly through vessels serving the placenta and fetus. No single estimated weight tells the whole story; the pattern, blood flow, fluid, and clinical context are considered together.

Possible contributors include placental dysfunction, maternal hypertension, infection, fetal or genetic conditions, and smoking or substance exposure. Sometimes no clear cause is identified. The care plan is based on current findings rather than assigning blame.

Keep appointments for repeat growth scans, Doppler studies, fetal heart monitoring, and maternal checks. Follow your maternity unit's instructions for noticing fetal movement, and report a reduction or clear change promptly. Balanced nutrition and prescribed supplements support general pregnancy health, but eating extra cannot by itself correct placental dysfunction.

Timing of birth balances the benefit of more time in the uterus against signs that the placenta may no longer support the fetus adequately. Stable findings may allow continued surveillance; concerning blood flow, fetal testing, growth pattern, or maternal illness may lead the team to advise earlier birth, sometimes through induction of labour and sometimes by caesarean birth.

Contact maternity care immediately if fetal movement is reduced or distinctly different from your baby's usual pattern. Do not wait for the next scan or try to provoke movement for a prolonged period before calling. Vaginal bleeding, leaking fluid, regular painful contractions, or severe abdominal pain also require prompt advice.

Urgent review is also needed for severe headache, visual disturbance, sudden swelling, pain high beneath the ribs, breathing difficulty, or feeling acutely unwell. These maternal warning signs can occur with hypertensive pregnancy complications that may also affect placental function.

Ask whether the fetus is small but following a steady pattern or showing evidence of growth restriction, and which finding is driving the diagnosis. Clarify how often surveillance is planned, what changes would alter the timing or mode of birth, where delivery should occur, and whether newborn support is expected after birth.