Summary
The aim of the study was to perform a retrospective review of records to test a possible significant association between sudden, modest weight loss (≤2 lb) between the last two prenatal appointments in the late 3rd trimester and onset of labour. Hospital and clinic records were searched for women who delivered a term baby after the onset of natural labour between 2006 and 2008, in Tulsa, OK. High-risk pregnancies were excluded. Patients were categorised by whether they lost or gained weight between their last two prenatal appointments. The groups’ average times to onset of spontaneous labour were compared. A total of 149 records were obtained. Mothers who lost weight had an average onset of spontaneous labour in 2.30 days; their counterparts’ average was 2.34 days. Student’s t-test and Wilcoxon test p values were 0.95 and 0.61, respectively. A Kolmogorov–Smirnov test p value was 0.2139. A one-half standard deviation difference in time to delivery, approximately 2.5 days, was detectable with 0.95 probability. It was concluded that these data may be the first time this question has been investigated and provide evidence that sudden, modest weight loss at the end of pregnancy is not associated with shorter time to onset of natural labour.