Fasting during pregnancy has adverse effects on fetal and adult health of the offspring.
In the case of Ramadan, the Islamic month of fasting, these effects can be avoided through
mothers timing pregnancy to avoid Ramadan during the gestation period. This paper examines
whether mothers time pregnancy to avoid Ramadan, and the mechanisms behind the avoidance
behaviour. Using fertility data from the Indonesian Family Life Survey on women in the
world’s largest Muslim country, I find strong evidence of Ramadan avoidance in the timing of
contraceptive use. Because mothers plan pregnancy to avoid Ramadan, the probability of using
contraceptives falls by 0.8 percentage points in the first month and by 1.2 percentage points
in the second month after Ramadan. Analyzing the timing of conception, I find that mothers
learn to avoid exposure to Ramadan from their prior experience of pregnancy during Ramadan,
although the effects are modest. Moreover, my results suggest that expansion of Indonesia’s
Village Midwife Program allowed mothers to use contraceptives, specifically birth control injections,
to avoid Ramadan, as I find no evidence of avoidance behaviour before the program
began. My findings imply a new channel through which family planning programs may improve
child health – by allowing mothers to effectively plan pregnancy to avoid predictable variation
in the prenatal environment.