Please cite this paper as: Rabindran R, Kanwar S, Lindow S. 24‐hour rhythm to the onset of term and preterm labour in twin pregnancies. BJOG 2010;117:1656–1657.
The objective of this study is to describe the time of onset of contractions in twin pregnancies that result in delivery, so as to investigate whether there is a diurnal influence. A UK maternity department database was used to identify twin deliveries over a 5‐year period, and the time of onset of labour was retrieved from these records. Two hundred and eleven women with spontaneous onset of labour in twin pregnancies were studied. A significant diurnal rhythm in the timing of contractions was noted, with 45% of deliveries occurring in labour that commenced between midnight and 08.00 hours. This periodicity is similar for twin pregnancies that end in preterm (24–36 weeks of gestation; χ2 = 17.2; P < 0.01) or term deliveries (37–40 weeks of gestation; χ2 = 13; P < 0.05). The periodicity of onset of labour in multiple pregnancies demonstrates a similar rhythm to singleton pregnancies, where labour most commonly begins between midnight and 08.00 hours.