We estimated that the 4,404,000 cancer deaths in women in 2020 resulted in 1,047,000 new maternal orphans globally. Almost half (48%, 508,000) of these children were in Asia and over one-third in Africa (35%, 370,000), while Europe (60,000 orphans), Latin America and the Caribbean (76,000), Northern America (28,000) and Oceania (6,400) together comprised the remaining 16% (Table 1). The predominance of these orphans in Asia and Africa was driven by six countries, which comprised two-fifths of the worldwide total—India (157,000), China (107,000), Nigeria (53,000), Indonesia (42,000), Ethiopia (39,000) and Pakistan (38,000) (Supplementary Table 1). In terms of contributing cancer sites, deaths from breast cancer were the single largest cause of new maternal orphans globally (25%), followed by cervix (20%) and upper gastrointestinal (GI) cancers (13%, of which the majority were gastric or esophageal) (Table 2). The ranks of these top three cancers varied between regions and HDI categories, although breast cancer deaths always occupied first or second place throughout (Fig. 1 and Extended Data Table 1). In Eastern and Southern Africa, cervical cancer deaths led to more maternal orphans than breast cancer deaths. These two regions were also the only two where female deaths from Kaposi sarcoma contributed substantially (4% in each). In Eastern Asia, upper GI cancer deaths led to more maternal orphans than breast and cervical cancer deaths. In Europe, New Zealand and Australia, respiratory cancer deaths (majority lung) were the second-leading cause of maternal orphans (11–18%) after breast cancer, with the exception of Eastern Europe where cervical cancer deaths ranked second (21%). Lower GI deaths (dominated by colorectal cancer) contributed to 5% of maternal orphans globally but represented at least 10% in Australia, New Zealand, North America and Northern Europe.

Cancer codes (ICD-10) included in each of the 14 cancer groups are listed in Extended Data Table 3.

In total, 63% of new maternal orphans arose from female cancer deaths at ages 35–49 years, with a mode at ages 40–44 years (Fig. 2), while 22% of orphaned children lost their mother when she was 50+ years and 16% under the age of 35 years. The contributing cancers to maternal orphans also shifted across these maternal age-at-death groups in each region, for example, with respiratory cancer deaths contributing to more maternal orphans for maternal deaths at older ages (Fig. 2 and Extended Data Fig. 1).

Cancer codes (ICD-10) included in each of the 14 cancer groups are listed in Extended Data Table 3. Percentages on top of bars are % of maternal orphans due to cancer in each age group. Percentages within bars are % of maternal orphans arising from each cause of cancer-related death within each maternal age at death group.

Apart from the total population size, the following two factors strongly influence a country’s total number of maternal orphans due to cancer. They are the average number of children under the age of 18 years per 100 female cancer deaths, largely reflecting past fertility (Fig. 3a), and the risk of cancer death among women at ages when most children remain under 18 years of age (i.e. deaths of women at ages 15–54 years which give rise to 92% of maternal orphans, Extended Data Fig. 2). The latter is a strong determinant of the number of maternal orphans due to cancer per 100,000 children, that is, a child’s risk of becoming a maternal cancer orphan independent of fertility rates (Fig. 3b).

a, Number of new maternal orphans due to cancer per 100 cancer deaths in women in 2020. b, Number of new maternal orphans due to cancer per 100,000 children in 2020. NA: Not available.

The number of new maternal orphans per 100 female cancer deaths was the highest in Africa and other low-/middle-income countries (LMICs) (Fig. 3a) due to their high fertility rates (Extended Data Fig. 3). This was particularly the case in Middle, Western and Eastern Africa (average 3−3.3 children <18 years per woman aged 40–44 years), thus the ratio of new maternal orphans per 100 female cancer deaths was over 110 in these countries. Conversely, the ratio of new maternal orphans per 100 female cancer deaths was lower than ten in regions of low fertility - and often higher HDI - such as Eastern Asia (including Japan and China), Europe and Northern America (Fig. 3a). Although these differentials were partly influenced by the younger demographic of Africa and other LMICs, a strong inverse relationship between new maternal orphans per 100 female cancer deaths and a country’s HDI remained when restricted to deaths under age 50 (Extended Data Fig. 4).

The 1,047,000 new maternal orphans globally translated to a global average of 40 orphans per 100,000 children. At a regional level, this number ranged from 15 in Malta to 113 in Malawi (Fig. 3b and Extended Data Fig. 5), but in 110 of 185 countries (59%) this number lay close to the global average, that is, between 30 and 50 orphans per 100,000 children (Extended Data Fig. 5). There was a general tendency for greater numbers of newly orphaned children per 100,000 children in countries with lower HDI (Fig. 4a), driven, for the most part, by the risk of cancer death in women at ages 15–54 years, which was highest in parts of Africa, followed by some Asian and South American countries (Extended Data Fig. 2). Indeed, of the 10% of countries with a ratio over 65 new maternal orphans per 100,000 children, 14 were in Africa (in descending order: Malawi, Mozambique, Cameroon, Djibouti, Uganda, Mali, Namibia, Equatorial Guinea, Burundi, Somalia, Comoros, Eswatini, Ethiopia and Lesotho), two in the Caribbean (Barbados and Jamaica) and three in Oceania (Papua New Guinea, Fiji and Samoa; Supplementary Table 1). In most of these listed African countries, as well as in Papua New Guinea and Fiji, cervical cancer mortality rates at ages 15–54 years were between two and eight times higher than the global average. Each of these countries also had high fertility rates. In contrast, in Jamaica (612 new maternal orphans in 2020) and Barbados (51 new maternal orphans), fertility rates and thus maternal orphans per 100 cancer deaths were not particularly high, but breast cancer mortality rates at ages 15–54 years were three to four times the global average. Outside of this top decile, other countries that had a high number of orphans per 100,000 children relative to other countries in their region were Serbia (56 new maternal orphans per 100,000 children) and Montenegro (54) in Europe—where female cancer deaths at ages 15–54 were dominated by breast, cervix and lung—Syria (61) and Myanmar (59) in Asia and Bolivia (58) and Peru (49) in South America. Conversely, there were several countries, such as Nepal, Niger and Bangladesh, where the number of new maternal orphans per 100 female cancer deaths was high, but the absolute risk of becoming a maternal orphan per 100,000 children was relatively low or moderate, due to the low/moderate cancer mortality rates in women. Finally, India and China make interesting contrasts. Both had similar numbers of new maternal orphans per 100,000 children (32), resulting from similar rates of female cancer mortality at ages 15–54 years, but India had 50% more orphans (157,0000) than China (107,000) due to its higher fertility rate and much younger population structure.

a, Number of new maternal orphans due to cancer per 100,000 children, in 2020, plotted against a country’s human development index. b, Average age at orphaning at their mother’s death, in 2020, plotted against a country’s HDI. Ten of 185 countries/territories are not included as they do not have an HDI value. They represent 10,000 new maternal orphans due to cancer in 2020.

Most newly orphaned children were aged 10 years or over at the time of cancer bereavement (69%), 21% were aged 5–9 years and 11% were aged under 5 years (Table 1). The mean age of new maternal orphans for most countries (166 of 185 countries, 90%) varied between 10.5 and 12.5 years, with a clear positive relationship of older age at orphaning in countries with higher HDI (Fig. 4b and Table 1). Note that these differences in age at orphaning by HDI were relatively small compared to international differences in age at first/last birth because many of the children born to younger mothers will be adults before a potential maternal cancer death (for example, a child born to a 20-year-old mother is an adult when the mother is 38 years and age of cancer diagnosis and thus potential cancer death is most often over age 38 years). These differences imply that, although 35% of all maternal cancer orphans occurred in Africa, this percentage was higher (43%) among the subset of these children who were under the age of 5 years at orphaning.

The number of prevalent maternal orphans due to cancer in mid-2020 was estimated to be 7,048,000. The geographic distribution (Table 1) was similar to that of new maternal orphans but prevalent orphans were older—approximately 4% were aged under 5 years, 16% were aged 5–9 years, and 79% were aged over 10 years (Table 1). Sensitivity analyses revealed that this estimate of 7,048,000 varied between 6,615,000 and 7,423,000 (Extended Data Table 2). The scenarios considered for the impact of maternal death on subsequent child survival only marginally altered the prevalence estimate (reducing the global prevalence by up to 90,000 (<1.5%)), whereas models with varying historic cancer mortality rates altered the estimates by up to ±375,000 (5.3%).