Small for Gestational Age Fetus: Causes, Diagnosis & Management Guidelines

2. Primigravida, 28 years old with precious pregnancy at 38 weeks gestation. • History of sluggish fetal movments. • O/E: B.P 120/70. • P/A: FH 32 weeks. • Long/ Cephalic. • FHS 95/ min regular.

3. BPP: 6/10. • Liqour Nil. • Heart rate 103 – 123. • EFW 1.6kg. • P/ V: No liqour or discharge. • Not in labour. • Pelvis adequate.

4. I.U.G.R INTRA UTERINE GROWTH RESTRICTION

5. INTRODUCTION • Small sized placenta. • Poor nutrient supply. • Reduced liqour. • Intrauterine fetal death. • Operative and instrumental deliveries.

6. Perinatal mortality is six to eight times higher. • 40% of the so – called unexplained still birth.

7. Classification • Very small for gestational age; • Below the 3rd centile. • Small for gestational age; • Below the 10th centile. • Appropriate for gestational age; • 10th to 90th centile. • Above 90th centile ; • Macrosomic

8. SMALL FOR GESTATIONAL AGE FETUSES. W.H.O Definition ; The term small for gestational age is used to describe a fetus whose growth parameters are below the 10th centile for a given gestational age.

9. NORMAL SMALL FETUS. • No structural anomalies. • Normal liqour. • Normal umbilical artery doppler study. • Normal growth velocity. • No underlying pathology.

10. I.U.G.R • Underlying pathology. • Abnormal Umbilical artery Doppler studies. • Further Classification. • Symmetrical I.U.G.R. • Asymmetric I.U.G.R.

11. PATHOPHYSIOLOGY

13. ASYMMETRICAL I.U.G.R.

14. SYMMETRICAL I.U.G.R. • Early pregnancy. • Congenital abnormalities. • Infections. • Poor prognosis.

16. ETIOLOGY AND RISK FACTORS

17. MATERNAL CAUSES • Malnutrition: • Symmetrical I.U.G.R.in 1st trimester • Asymmetrical I.U.G.R. in 2nd trimester

18. Smoking: • Increased risk is in women who smoke in third trimester and consume more than ten cigarettes per day. • Increased levels of fetal carboxyl hemoglobin.

19. Alcohol: • 12 fold increased risk of I.U.G.R . • more than 15 units (120g) of Alcohol leads to reduction of 66g of birth weight. • RCOG recommendation in pregnancy. • Causes symmetrical I.U.G.R.

20. Drugs of abuse: • Heroine and methadone. • TherapeuticDrugs: • B-Blockers , Phenytoin, Anticancer drugs and narcotics

21. MaternalDiseases: • Cardiorespiratorydiseases. • Anti phospholipid antibody syndrome. • Diabetes. • Chronic hypertension. • Anemia, sickle cell disease, collagen vascular diseases and maternal malabsorption syndrome.

22. PLACENTAL CAUSES • NORMAL CHANGES IN PREGNANCY • Increase in blood flow from 150ml/min to 600ml/min at term • first layer of trophoblastic invasion in 1st trimester. • 2nd layer of trophoblastic invasion before 20 weeks. • Smooth muscles destruction of spiral arteries.

23. I.U.G.R. • Second wave of trophoblastic invasion does not occur. • Reduced end diastolic flow velocity. • Decreased oxygen supply to the fetus.

24. OTHER PLACENTAL FACTORS • Small placental size. • Antepartum hemorrhage. • Thrombosis. • Infarction. • Chrioamnionitis.

25. Placental cysts. • Chorioangioma. • Placentitis. • Edema.

26. FETAL CAUSES • Chromosomal abnormalities. • Gastrochisis. • Major cardiac defects. • Fetal infections.

27. UTERINE CAUSES • Congenital Uterine anomalies. • Large Uterine fibroids.

28. DIAGNOSIS OF SMALL BABY

29. HISTORY • Age. • LMP. • APH. • Hyperemesis. • Medical history. • Medication. • Obstetric. • Family history.

30. G.P.E. • B.P. • Pallor. • Dependant edema. • Weight. • Height. • Relevant systemic examination.

31. Abdominal Examination. • Fundal height measurement. • Sensitivity is 60% - 80%. • Positive predictive value is 20% - 80 %.

32. Pelvic Examination. • Per speculum examination in cases of ruptured membranes.

33. Investigations Ultra sound: • BPD, FL and AC . • AC has higher sensitivity and greater negative predictive value. • Type of I.U.G.R. • Serial growth scans. • Four weekly measurement.

36. Fetal Weight. • Normally 500g at 24 weeks, 1 Kg at 28 weeks, 3.5 kg at 40 weeks. • Formulae • Campbell. • Shephard. • Hadlock.

37. Liqour Volume • Maximum vertical pool of 2 - 8 cm. • AFI. • After 30 weeks it is between 8 – 25 cm. • AFI of less than 6 cm should be considered seriously.

38. Doppler • Arterial flow is pulsatile and venous is constant. • Resistance to flow is reflected in the diastolic component. • Reduced EDF indicates high resistance.

39. Uterine Artery Doppler. • Studied at 20 weeks. • Sensitivity is upto 85%. • Wave form with high resistance or with a notch indicates that the spiral arteries are muscular.

41. Umbilical Artery Doppler • Performed on high risk mothers. • Diastolic flow is reduced in I.U.G.R. • Absent end diastolic flow is a sign of fetal hypoxia. • Reversed end diastolic flow occurs in severe cases.

43. Pulsatility Index • Systolic – end diastolic peak velocity • Time average maximum velocity. • Resistance Index • Systolic – end diastolic peak velocity • Systolic peak velocity

44. Systolic to Diastolic Ratio Systolic peak velocity Diastolic peak velocity

45. Middle Cerebral Artery Doppler.

46. Venous Doppler • Reversed flow • Ductus Venosus. • Umbilical vein pulsations.

47. Other Tests • Biophysical profile. • CTG. • Karyotyping. • Biochemical markers

48. Prophylaxis • Low dose aspirin. • Cessation of smoking. • Supplementation. • Bed rest.

49. Aims of management • Determine the type. • Identify underlying cause. • Deliver at optimum time.

50. SCHEME OF MANAGEMENT FOR THE SGA INFANT