Of every pair of indicators compared across this atlas, this is the tightest. Sanitation access and maternal mortality correlate at −0.80 across the 184 countries with both figures — accounting for roughly 64% of the variation in how many women die in childbirth.

That is stronger than the link between maternal death and national income, doctors per head, or health spending. Toilets predict maternal survival better than money does.

The numbers

Sanitation access runs from Ethiopia at 10.4% of the population to a cluster of countries at effectively 100%. Maternal mortality runs from Nigeria at 993 deaths per 100,000 live births to Norway at 1.

Read that second range again. A woman giving birth in Nigeria faces a risk roughly a thousand times higher than one giving birth in Norway. There is no other health statistic in this atlas with a spread like it.

The countries at the difficult end:

• Chad — 13.1% sanitation access, 748 maternal deaths per 100,000
• Central African Republic — 14.0%, 692 deaths
• South Sudan — 14.4%, 692 deaths
• Liberia — 23.3%, 628 deaths
• Benin — 22.3%, 518 deaths
• Madagascar — 15.4%, 445 deaths

And the other end:

• Belarus — 99.8% sanitation, 1 maternal death per 100,000
• Australia — 100%, 2 deaths
• Israel — 99.9%, 2 deaths
• Japan — 99.9%, 3 deaths
• Spain — 99.9%, 3 deaths
• Norway — effectively universal, 1 death

Sanitation is not the cause

It is worth being direct about this, because the correlation is strong enough to invite a bad conclusion.

Poor sanitation does contribute to maternal death — puerperal sepsis, infection following delivery, is among the leading direct causes worldwide, and it is far more likely where deliveries happen without clean water and safe waste disposal. That link is real and mechanical.

But it does not carry a correlation of −0.80 on its own. What sanitation coverage actually measures, at a national scale, is whether the state can deliver infrastructure to everyone. Building sewerage or safe latrines for an entire population requires sustained public investment, functioning local administration, and reach into rural areas. A country that has managed that has almost certainly also managed antenatal clinics, skilled birth attendants, emergency obstetric referral and blood supply.

So sanitation access works here as a proxy for state capacity, and state capacity is what keeps women alive in childbirth. The plumbing and the midwives arrive together because the same institutions deliver both.

This is why the correlation beats income. A country can have oil revenue and still not reach its villages. Sanitation coverage only goes up when the reaching actually happens.

What actually prevents maternal death

The clinical picture is well established and unusually actionable. The direct causes — haemorrhage, hypertensive disorders, sepsis, obstructed labour — are all treatable with interventions that are neither new nor expensive. What they require is a skilled attendant present at the birth and a working route to emergency surgery within hours.

That is why maternal mortality responds so sharply to system-building rather than to technology or spending. Countries that have cut it fastest did so by getting births into facilities with trained staff, not by buying anything advanced.

Caveats

The extremes are estimates. Maternal deaths are undercounted almost everywhere and undercounted worst where they are most common. The figures for the highest-mortality countries are modelled with wide uncertainty intervals — Nigeria's 993 should be read as an estimate of scale, not a precise count.

"Basic sanitation" is a low bar. It means an improved facility not shared with other households. It does not mean sewerage, treatment, or anything approaching what the near-100% countries actually have. The top of this range compresses enormous real differences.

The years differ slightly — sanitation from 2024, maternal mortality from 2023 — which is standard for this kind of comparison.

The takeaway

The gap between 1 maternal death per 100,000 and 993 is not a gap in medical knowledge. Every country in the world knows how to prevent these deaths. The difference is entirely in whether the state reaches the people who need it, and sanitation coverage turns out to be one of the cleanest available measures of that.

Explore the full maps for sanitation access and maternal mortality, or try the daily map game. Source: World Bank Open Data, 2023 and 2024.