National Minimum Data Set (NMDS) Perinatal:

Required to analyse pregnancy outcome according to birth order and identify the individual baby resulting from a multiple birth pregnancy. Multiple births have higher risks of perinatal mortality and morbidity. Multiple birth pregnancies are often associated with obstetric complications, labour and delivery complications, higher rates of neonatal morbidity, low birthweight, and a higher perinatal death rate.

Data Set Specification (DSS) - Health care client identification:

While this piece of information is normally recorded for multiple births against the mother's record, if the health care client volunteers the information, it should be recorded.