The demographics of molar pregnancies in England and Wales from 2000-2009.

OBJECTIVE To analyze the overall incidence of molar pregnancies and that of complete and partial molar pregnancies across the reproductive age range for England and Wales for the period 2000-2009. STUDY DESIGN The cases of all patients with molar pregnancies registered with the UK Trophoblast disease service from England and Wales were identified. The overall number of molar pregnancies registered from 1998-2007 was compared to the number of maternities (live births and still births) and total viable conceptions for each year. For the series 2000-2009 the number of complete and partial molar pregnancies were compared to the number of maternities and terminations occurring for women across the age range < 14 to 50+ years, allowing an accurate estimate of the risk of molar pregnancy for women conceiving at any age. RESULTS The results indicate that for the period 1998-2007 the overall incidence of molar pregnancies was 1 case per 591 viable conceptions. The incidence increased from 1:611 in 1997 to 1:528 in 2008. The age-specific data for the period 2000-2009 confirms a risk level of < 0.2%for women aged 18 {N dash} 39 years, with a modest excess risk for young teenagers but a much more significant increase for women > 40, where the risk is 1% at 45 and 17% at > or = 50. CONCLUSION This study provides detailed data regarding the risk of partial and complete molar pregnancies with increasing maternal age. It confirms that the risk of partial molar pregnancy varies relatively little with age, with complete molar pregnancies contributing the main component of the overall increase with age.