Randomization
Random allocation to one of three perineal management strategies was performed in a ratio of
1:1:1 within balanced blocks of 12. A computer program was used to generate the random
allocation series. For each dozen women, four were allocated to compresses, four to massage,
and four to hands off, but the sequence varied randomly. Next, sequentially numbered, sealed,
opaque envelopes were prepared by the database manager and study administrator, and stored
in a metal box at a designated place (with restricted access) in the hospital’s labor unit. The
clinical midwife selected the lowest numbered envelope, once vaginal birth appeared likely.
The envelope contained a card with the study group allocation (warm compresses, massage
with lubricant, no touch) and a data sheet to be completed after the birth. When the envelope
was drawn, the midwife signed the study register and noted the date and time.