Sources of birth data in the LS

The principal sources of data on birth in the LS are:

  • Where the subject of analysis is the infant: new births of LS sample members since Census Day 1971: table NBIR
  • Where the subject of analysis is the mother: live-births and stillbirths to female LS sample members since Census Day 1971: tables LBSM and SBSM

More detailed list, including those above:

The birth of an LS member before Census Day 1971:
Can only be studied indirectly, via the characteristics of his/her mother at a Census where both LS member and mother are in the same household. For example, for an LS member who is aged 10 at the 1981 Census and whose mother is in the same household, the age of the mother would indicate whether the LS member was the result of a teenage pregnancy.

The 1971 Census is particularly useful in this regard, as ever-married women aged 16-59 were asked to list the dates of birth of their legitimate, live-born children. However, the LS member will be missing from the mother's list of births if s/he was illegitimate, or if s/he was not among the mother's first six children and also not the latest child (the maximum length of the list is 7). With these provisos, it is usually possible to establish the LS member's position in the birth order and whether s/he is a single or multiple birth. The number of siblings can only be known as at Census Day 1971, as the mother may have more children after that date. However, there is no geographic restriction on where in the world the LS member's birth took place (unlike the next source).

The birth of an LS member in England or Wales after Census Day 1971:
Will cause a record to be created in table NBIR, containing all the data from the Birth Registration form, even if the child dies on the same day. (However, if the mother's usual address was outside England and Wales, the child will not be eligible for the LS even though s/he has an LS birthday.) From the Birth Registration data it is possible to identify the LS member's position in the birth order and whether s/he is a single or multiple birth; other data include place of birth and birthweight (although researchers are recommended not to use birthweight before 1981 as it is notably incomplete) as well as geographic indicators.

The birth of an LS member outside England or Wales after Census Day 1971:
Will have no data recorded in the LS. The LS member will enter the LS when s/he is enumerated at a Census or registers with the NHS, whichever happens first. If s/he enters the LS by registering with the NHS, a record will be created in table IMMG and s/he will be assumed to have arrived in England and Wales since the last Census.

The birth of a child to a female LS member before Census Day 1971 and/or outside England and Wales:
Can only be inferred if (a) the child is in the same household as the LS mother at a Census, or (b) if the LS mother is ever-married and aged 16-59 at the 1971 Census, in which case she will have been asked for the dates of birth of her legitimate, live-born children, or (c) if the LS mother has a further birth and gives the number of her previous, legitimate, live-born and still-born children at the Birth Registration.

The birth of a child to a female LS member in England and Wales from Census Day 1971:
Will cause a record to be created in table LBSM, containing all the data from the Birth Registration form. Both live births and stillbirths will be recorded (stillbirths in table SBSM) and multiple births identified. The birth registration includes the number of the mother's previous, legitimate, live-born and still-born children.

Back to list for birth

Last modified 8 August 2011