Discrepancy in Uterine Size

Important points when addressing a pregnancy which doesn't correspond to the expected gestational size

1. DISCREPANCY IN UTERINE SIZE An understanding of the issues involved when a uterus doesn’t correspond to its gestational age

2. By Associate Professor Dr Hanifullah Khan

3. To understand the definitions involved To understand the implications of this situation The important points to consider Objectives

4. Discrepancy – what is it? W hen the uterine size does not correspond to the expected gestation May be larger or smaller Objective measurement - > 2 cm variation with symphysiofundal height (SFH)

5. Points to consider The patient has been found to have a gestation which does not correspond to calculations. This may be a feature of an underlying problem The problem may be related to the mother, fetus or placenta It is our job to determine the underlying cause of this problem

6. Dates Be absolutely positive The mother remembers the exact LMP (1 st day) The periods have been regular The onset of pregnancy symptoms & quickening correspond to the dates That an early pregnancy ultrasound (if done), confirmed the dates Subsequent antenatal check ups have noted previous corresponding growth of uterus In all cases, always begin by confirming the dates

7. Remember, an early pregnancy ultrasound scan is the definitive decider of dates

8. IUGR Intrauterine growth restriction or Fetal growth restriction Leads to uterus < dates A manifestation of underlying problem Maternal, fetal or placental Most commonly caused by placental insufficiency (unknown cause), hypertensive disease, maternal disease, fetal anomaly Most non-fetal causes lead to asymmetrical FGR (the so-called head-sparing effect)

9. Fetal Growth Restriction Leads to long term problems

10. The left ear

11. Big baby If fetal macrosomia is the cause in an uterus > dates, it is most often a consequence of gestational diabetes GDM can also lead to polyhydramnios on its own It is mandatory to look hard for GDM in such cases

12. Macrosomia

13. Fetal anomalies Any discrepancy in uterine size must lead to an extensive search for fetal anomalies

14. Multiples Any large uterus may be caused by more than one passenger in it See for yourself

15. The diagnosis of SGA A constitutionally small fetus is a diagnosis of exclusion This is the last diagnosis in your list of differentials Always rule out disease before you can say its normal These fetuses display linear growth despite being small Usually, the mother is also small (this is logical)

16. Summary

17. Discrepancy in uterine size This denotes a uterine size not corresponding to gestational age It may be a sign of an underlying problem This problem could be of maternal, fetal or placental origin One common cause is wrong dates Rule out disease before diagnosing a constitutionally small fetus

18. THE END Thank You Very Much