The number of women getting pregnant over the age of 35 is rising and the number aged 40 and above has more than doubled since 1990, according to figures from the Office for National Statistics.
The figures also show a record drop in the number of teenage pregnancies and a fall in pregnancies for women under 35 in general.
The ONS says the largest percentage increase in conception rates occurred among women aged 35 to 39 (1.7%). A smaller increase in conception rates was recorded among women aged 40 and over (1.4%). Conception rates for women aged under 20 and 20 to 24 decreased by 8.4% and 4.3% respectively. Rates for women aged 25 to 29 and 30 to 34 decreased by smaller amounts (0.5% and 0.3% respectively).
The conception rate for women aged 40 and over has more than doubled since 1990 from 6.6 to 14.2 conceptions per thousand women. The number of women in this age group conceiving has risen from 12,032 in 1990 to almost 29,000 in 2011, 2012 and 2013.
The ONS says the reason why more women are giving birth at ages 30 and above include increased participation in higher education, increased female participation in the labour force, the increasing importance of a career, the rising costs of childbearing, labour market uncertainty, housing factors and instability of partnerships.