The effect of maternal fasting during Ramadan on preterm delivery: a prospective cohort study

To determine the effect of fasting during the month of Ramadan on the rate of preterm delivery (PTD).

A prospective cohort study of women with singleton pregnancies who elected to fast and matched controls.

Four medical centres in Beirut, Lebanon.

Women presenting for prenatal care (20-34 weeks of gestation) during the month of Ramadan, September 2008.

Data were collected prospectively. The frequency of PTD was evaluated in relation to the duration of fasting and the stage of gestation at the time of fasting.

The primary endpoint was the percentage of pregnant women who had PTD, defined as delivery before 37 completed weeks of gestation.

A total of 468 women were approached, of whom 402 were included in the study. There were no differences in smoking history and employment. There was no difference in the proportion of women who had PTD at <37 weeks (10.4% versus 10.4%) or PTD at <32 weeks (1.5% versus 0.5%) in the Ramadan-fasted group and the controls, respectively. The PTD rate was also similar in those who fasted before or during the third trimester. The mean birthweight was lower (3094 ± 467 g versus 3202 ± 473 g, P = 0.024) and the rate of ketosis and ketonuria was higher in the Ramadan-fasted women. On multivariate stepwise logistic regression analysis, fasting was not associated with an increased risk of PTD (odds ratio 0.72; 95% confidence interval 0.34-1.54; P = 0.397). The only factor that had a significant effect on the PTD rate was body mass index (odds ratio 0.43; 95% confidence interval 0.20-0.93; P = 0.033).

Fasting during the month of Ramadan does not seem to increase the baseline risk of preterm delivery in pregnant women regardless of the gestational age during which this practice is observed.