Data published by the Office of National Statistics, show clearly that the increasing gap between conceptions and births is due to the increasing number of abortions. The ONS notes: “Prior to 1969, the first full year for which abortions data were available, the number of conceptions was equivalent to the number of births.”
In 1977, the year in which annual births hit a low, the gap between conceptions and births was 112,000 compared to the number of abortions which was 102,000.
In 2019, the gap between conceptions and births had increased to 181,000, and in the same year abortions were 207,000.
Conceptions reported in one calendar year might result in a birth or an abortion in the same year or in the following year, so annual numbers might not always sum to exact totals.