Abdominal decompression was first used to increase blood flow and the forward movement of the uterus during labour contractions as a way of relieving pain. A rigid covered dome is placed about the abdomen and the space around the abdomen is decompressed to -50 to -100 mm Hg for 15 to 30 seconds out of each minute for 30 minutes once to thrice daily, or continuously during labour. Observations that fetal wellbeing appeared to be improved led to its investigation for complications of pregnancy.
Three randomised controlled studies with a total of 356 pregnant women were identified from a search of the medical literature, all with the possibility of containing serious methodological limitations. The studies were reported on between 1967 and 1973. One study involved women with pre-eclampsia, essential hypertension, or chronic nephritis. The other two trials assigned women carrying babies that were small for their gestational age to abdominal decompression or no decompression.
Abdominal decompression appeared to have a beneficial effect on the progression of pre-eclampsia. This one trial also reported less fetal distress during labour and fewer low 1-minute Apgar scores in the group who received abdominal decompression. The apparent large improvement in birthweight and perinatal deaths reported in all three studies is sufficiently striking to warrant the further evaluation of abdominal decompression in cases of impaired fetal growth, and possibly for women with pre-eclampsia, by means of methodologically sound controlled trials. Because of the methodological shortcomings mentioned above, clinical use of abdominal decompression cannot be supported on the basis of the present trials.