One in five children born as a twin in sub-Saharan Africa dies before the age of five and improvements in survival are lagging behind single-borns – with mortality for twin births reducing by a third between 1995-2014 while it halved for single-borns, according to a study published in The Lancet Global Health journal.
The study is the first to analyse trends in mortality of twins in sub-Saharan Africa, despite the region having the highest childhood mortality rate and the highest rate of natural twin births in the world (18 per 1000 pregnancies, compared with 6-9 per 1000 in East Asia and Latin America and 8-16 per 1000 in Europe, North America and the Middle East).
With the number of under-five year olds in the region set to grow by 20% by 2030, the study illustrates the need for improved care before, during and after birth as countries in sub-Saharan Africa work to further reduce child mortality rates.
Twin births carry higher risks for the children and mother, including early delivery and low birthweight for the twins, and anaemia, post-partum haemorrhage and high blood pressure for the mother. Globally, twins are two to five times more likely to die under the age of five than single-born children. In sub-Saharan Africa these risks are compounded by higher birth rates and poor maternal and newborn care.
The study used data on 1.69 million children born in 30 sub-Saharan African countries between 1995 and 2014, including 56597 twins. Between 1995 and 2014, 190642 children died before the age of five, including 16399 twins.
Single-born mortality halved over the 20-year period (51%, from 128.6 to 63.5 deaths per 1000 live births), while it reduced by around a third for twins (35%, from 327.7 to 213.0 per 1000).
As a result of this slower reduction in mortality, twin deaths accounted for a larger share of under-five mortality over time – with one in 10 (10.7%) under-five deaths in 2009-2014 being a result of a twin death (equivalent to an estimated 315000 twin deaths each year in sub-Saharan Africa). Similarly, twin deaths accounted for 15.1% of all neonatal deaths in 2009-2014 (equivalent to approximately 150000 deaths a year).
Between 2009-2014, almost two-thirds (64%) of twin deaths occurred in the first month of life. Comparatively, less than half (43%) of single-born deaths occurred in the first month.
Twin births were more common in women in their 30s and women who had been pregnant four or more times before. Women giving birth to twins were more likely than those with single-borns to give birth in a medical setting or have medical assistance, but the figures still remained low – with less than two-thirds (62.5%) giving birth in some form of clinic or hospital and only half (51.7%) having medical support at birth. The researchers propose that improving medical support could reduce twin mortality in sub-Saharan Africa.
“Despite the decline in childhood mortality in sub-Saharan Africa over the last few decades, our study demonstrates that these declines are not as dramatic for twins,” says Professor Christiaan Monden, University of Oxford, UK. “So far the poor fate of twins has gone largely unnoticed by policy makers. Improved medical support to mothers and their twins will be crucial for the child and maternal health. First, it’s important to detect twin pregnancies early in order to provide specialist antenatal care and refer the mother to give birth in a hospital. During birth, it’s vital that staff trained in twin deliveries are available, as well as appropriate facilities. Lastly, Twins will need continued monitoring after birth in the early phase of life, where they have high mortality in the first few days and months and a higher risk of complications such as congenital malformations and neurodevelopmental disabilities. If care for twins and their mothers does not improve considerably in the coming years, the absolute numbers of twin deaths will hardly decrease.”
“So far the poor fate of twins has gone largely unnoticed by policy makers. Improved medical support to mothers and their twins will be crucial for the child and maternal health. First, it’s important to detect twin pregnancies early in order to provide specialist antenatal care and refer the mother to give birth in a hospital. During birth, it’s vital that staff trained in twin deliveries are available, as well as appropriate facilities. Lastly, Twins will need continued monitoring after birth in the early phase of life, where they have high mortality in the first few days and months and a higher risk of complications such as congenital malformations and neurodevelopmental disabilities. If care for twins and their mothers does not improve considerably in the coming years, the absolute numbers of twin deaths will hardly decrease.”
Co-author of the study, Dr Jeroen Smits, Radboud University Nijmegen, The Netherlands, says: “Without special attention to this vulnerable group it will be very difficult to achieve the Sustainable Development Goal 2030 target of fewer than 12 per 1000 neonatal deaths and fewer than 25 per 1000 under-5 deaths, or the Every Newborn 2035 target of fewer than ten per 1000 neonatal deaths.”
The researchers note that their figures could be an underestimate as a result of under-reporting of twin births and deaths, for instance, some twins may be wrongly registered as a single-birth if only one child survived.
Writing in a linked Comment, Dr. Kaare Christensen, The Danish Twin Registry, Denmark, said: “… a continued progress in twin early-life survival in sub-Saharan Africa is likely to also have a positive impact in the future with better later-life health for twins, making increased attention to mothers of twins and the health care of their infants in sub-Saharan Africa even more pertinent. In this context, WHO should consider including twins specifically in the recommendations for postnatal care, which is currently not the case.”
