Are the pituitary gonadotrophins determinants of complete molar pregnancy? An investigation using the method of least squares.

Objective: To look for a relationship between the maternal age-specific incidence of complete molar pregnancy and the age-specific mid-follicular levels of circulating follicle stimulating hormone and luteinizing hormone.

Design: Calculation of correlation coefficients between the incidence of complete mole and the circulating levels of follicle stimulating hormone and luteinizing hormone using the method of least squares.

Setting: England and Wales.

Participants: All mothers between 23 and 49 years delivering in England and Wales between 2000 and 2009 inclusive and a sample of women between 23 and 49 years from Sheffield (1987).

Main outcome measures: The bivariate correlation coefficients between the incidence of complete mole and the mid-follicular plasma levels of the pituitary gonadotrophins.

Results: Exponential correlation between the incidence of complete mole and mid-follicular plasma follicle stimulating hormone, r = 0.965, r (2 )= 0.932. Linear correlation between the incidence of complete mole and mid-follicular plasma luteinizing hormone, r = 0.972, r (2 )= 0.944. Multivariate exponential regression between the incidence of complete mole and the combination of follicle stimulating and luteinizing hormones. This does not improve the prediction of the incidence of complete mole and it shows that luteinizing hormone is not a significant predictor of the incidence of complete mole in the presence of follicle stimulating hormone.

Conclusions: There is a strong positive exponential correlation between the maternal age-specific incidence of complete mole in England and Wales and the age-related mid-follicular levels of follicle stimulating hormone in a sample of English women.