Table 1.

Total risk of pre-eclampsia in first and second pregnancy for mothers who had two pregnancies with same father and mothers who had two pregnancies with different fathers. Data from Medical Birth Registry of Norway, 1967-92

Detail	No of pregnancies	Mother’s 1st pregnancy			Mother’s 2nd pregnancy
		Risk (%)	Mean (SD) age of mother (years)		Risk (%)	Mean (SD) age of mother (years)
Pregnancies with same father	363 758	3.4	24.0 (3.8)		1.7	27.2 (4.1)
Pregnancies with different fathers	14 266	3.0	21.7 (3.3)		1.9	28.5 (4.7)