Menarcheal age and spontaneous abortion: a causal connection?

Data from a Norwegian investigation on family planning were used to study the relation between menarcheal age and spontaneous abortion rate. Abortion rates were found to be 1.5-2 times higher among women with a menarcheal age of 12 years or less than among those with a menarcheal age of 14 years or more. The possibility that the difference in rates could be attributed to social factors was examined, but no significant relation of this kind was found. The connection between menarcheal age and spontaneous abortion rate may explain the low fertility of early maturers reported by Kiernan (Ann Hum Biol 4:301-308, 1977).