The following statements relating to pregnancy in a 38-year-old woman are correct:

1. Her risk of a child with neural-tube defect is ten times greater than at the age of eighteen years.

2. Chorionic villus biopsy will allow diagnosis of neural-tube defect.

3. Her risk of a child with Down syndrome is less than 1%.

Down syndrome

4. has an incidence in the United Kingdom of approximately one in 700 live births.

5. is more commonly due to translocation than to nondisjunction.

The following disorders are correctly associated with their mode of inheritance:

6. glucose-6-phosphate dehydrogenase deficiency : X-linked recessive.

7. polycystic disease of kidneys (adult form) : multifactorial.

8. von Willebrand's disease : autosomal dominant.

Methods of value to distinguish the fetus with intrauterine growth restriction from that of uncertain gestational age include

9. increasing ratio of head to abdominal circumference measured by ultrasound.

10. measurement of fetal breathing activity.

11. cardiac volume.

Recognised causes of nonimmunological hydrops fetalis include

12. cytomegalovirus infection.

13. alpha-thalassaemia.

14. renal agenesis.

An increased risk of fetal malformation is associated with

15. the presence of a single umbilical vein.

16. smoking 20 cigarettes or more a day.

17. rubella vaccination in the first trimester of pregnancy.

The fetal alcohol syndrome

18. is associated with an increased incidence of postmaturity.

19. seldom occurs with alcohol ingestion by the mother of under eight units per week (one unit = one glass of wine).

20. is reversed by a high intake of vitamins.