Hundreds of millions of Muslims in Pakistan and around the world are fasting this Ramzan. Ramzan is a time when practicing Muslims spend an increased amount of time in devotion and worship, and we also spend more time tending to the needs of our friends and families. But while we do this, are we overlooking the health of expecting mothers, and indirectly the health of the future generation of Pakistanis? After all, fasting is not prescribed for everyone – pregnant women and those who are sick in general are among the exempt.

About 75 per cent of all pregnancies overlap with Ramzan in any given year, suggesting that more than 155 million Pakistanis and more than a billion Muslims living today were exposed to Ramzan in utero. Although Islamic law exempts pregnant women from fasting, there is evidence from diverse settings that more than 70-90 per cent of pregnant Muslim women fast during some part of Ramzan. Perhaps the notion is that while they can’t keep all 30 rozas, they should still try to keep as many as they can?

In research published in the Journal of Development Economics in 2015, I utilized the timing of Ramzan with respect to the timing of pregnancies to compute the long-term effects of nutritional disruptions in utero due to fasting on children’s cognition and on the labour force. Using a rich dataset from Indonesia, the largest Muslim-majority country in the world, I found that compared to Indonesian children with no overlap with Ramadan in utero, those exposed to Ramzan in utero scored 7-8 per cent lower on test scores. As adults (15-65 years old), the exposed children worked 4.7 per cent fewer hours per week and were more likely to be in a less skill-intensive sector. Similar effects were not found on Muslims who identified as “less religious” or non-Muslims whom I treated as a placebo for my analysis.

In a follow-up study forthcoming in BMJ Global Health, I along with my colleagues, discovered that Ramzan affects the poorest women the most. A full month of exposure to Ramzan in utero led to significant reductions that were concentrated in the bottom halves of the outcomes we study. For instance, among 8-15-year-old girls, in contrast to the average girl in our sample who witnessed a 9.2 per cent reduction in test scores, those who scored at the 10^th and 25^th percentile witnessed a 19 per cent decline in their scores.  The average boy saw a mean decline of 5.6 per cent, but a boy scored at the bottom 10^th percentile witnessed a 12.5 per cent decline in their cognitive scores.

Exposed children worked 4.7 per cent fewer hours per week and were more likely to be in a less skill-intensive sector.

Despite test scores affecting the “poorest” boys and girls, interestingly we find that the labour supply effects were only among women. In particular, in contrast to an average decline of 7.5 per cent in hours worked per week for a women aged 15-65 (working age), women whose hours worked were at the bottom 10^th percentile witnessed a massive 26.3 per cent reduction in their hours worked/week if they were exposed to Ramadan in utero.

Scientists have long debated the role of nature vs. nature in shaping human development. The debate involves whether human behaviour is shaped by a person’s genes or the environment one lives in (e.g. the kind of diet they receive). If it’s all genes, we may possibly expect that a malnourished foetus will be destined by their biology to be sick, less smart and less productive over their lives. In that case there may be possibly little room for remediation among malnourished children. This will also suggest in our case that the long-term effects I documented above are shaped entirely by a one off exposure to Ramzan in the uterus. In contrast, if nuture matters, the effects we observe in the long-term may be not only due to women’s decision to fast in pregnancy, but also shaped by responses of parents towards their sick children after birth as well. For example, if parents take a sick child exposed to Ramadan in utero to the doctors in their first few years of life and that helps remedy some of the developmental deficit, we may think that nurture matters and it’s not just biology shaping our destiny.

So, how much of the adverse effects that we observe from exposure to Ramzan in the uterus are due to fasting as compared to changes in other behaviours by parents? To address this, we conducted a major data analysis exercise crunching numbers from more than 20 years (1993-2014) of nationally representative data from Indonesia studying parental investments in their children across the life course: 0-5, 5-15 and the time around marriage of adult children. We find that 0-5 year olds who were exposed to Ramadan in utero are 3 per cent less likely to get vaccinated and are less likely to eat protein. We don’t find any effects of Ramadan on parental investments for 5-15-year-old kids. The period between age 0-5 is a critical period in a child’s life and our work suggests that perhaps the cumulative effect of fasting in utero compounded by further reductions in healthcare spending and protein intake for exposed children which may be leading to the adverse effects on cognition and labour market outcomes that I documented earlier.

Expectant families’ choices in Ramzan potentially affect the life course development and economic productivity of generations of Pakistanis.

The second half of the paper studies how applicable the results from Indonesia are for Muslims in other low and middle income contexts. We discovered something remarkable. While in some countries, such as Pakistan, Muslim parents tend to invest less in their exposed children, in other countries, such as Kenya, parents may spend more on healthcare to attempt to remedy developmental deficits among the exposed children. However, we see an interesting pattern: Higher GDP/capita acts as a buffer so that in countries with higher income (real PPP adjusted GDP/capita) parents are less likely to not vaccinate their exposed kids. One of the sad realities of poverty is that many parents have to make hard choices prioritising investing in “bread winners” among their own children often at the cost of sick children. In contrast, many richer countries have welfare programmes that provide support to poor parents in hard times.

By affecting the foundation of life, the foetal period, what we do in Ramzan potentially affects the life course development and economic productivity of generations of Pakistanis, and beyond. In fact, what we do in Ramzan can also lead to different behavioural responses by ourselves towards our children long after Ramzan is over without us even consciously knowing.

Families with pregnant women who plan to fast this Ramzan should pay serious attention to women’s diet, sleep routines, stress levels and consumption patterns during this month. Not to mention they should consult and visit their doctors regularly. Although fasting is a very personal decision, I hope these findings will help expectant mothers and families, make more informed choices this Ramzan. The choice to fast during pregnancy may not only affect the mothers but also their children’s economic well-being and health over their lifetime.

Beyond pregnant women and their families, much needs to be done at the policy level. Currently we lack a systematic policy approach to improve the experiences of fasting families in Ramzan. We need to monitor how many pregnant women and potentially ill Pakistanis fast, how much do they fast, what their demographics are in different regions. Such programs need to be sensitive to diverse individual and family beliefs but at same time ensure that pregnant women and their families make more informed choices, and have enabling environments that encourage them to make the healthiest choices. Let’s make Ramzan Mubarak.