Percentage of birth defects by cause in high income countries.
There is paucity of knowledge on the causes, diagnosis, management and prevention of fetal congenital anomalies in Africa. The chapter will highlight on the general causes and specific factors concerning congenital anomalies in Africa. The problems of diagnosis and management of congenital anomalies will be extensively discussed. There is also going to be a discussion on how fetal anomalies contribute to maternal and perinatal mortality and morbidity. Screening of congenital anomalies is another black point and will be discussed emphasizing on simple strategies applicable in resource constrained environment. A section will be dedicated on prevention of fetal congenital anomalies, particularly prevention of specific factors that increase the risk of fetal anomalies in Africa. Finally, there will also be discussion on collaborative care as a panacea in the management of fetal congenital fetal anomalies, including my experience in this area. Specific examples will be given to illustrate the utility of collaborative in resource limited countries.
Congenital anomalies can be defined as structural or functional anomalies [e.g. metabolic disorders] that occur during intrauterine life and can be identified prenatally, at birth or sometimes may only be detected later in infancy, such as hearing defect . Every year, an estimated 7.9 million children are born with serious birth defects of genetic or partly genetic origin . Over 1 million more infants are born with serious birth defects of post-conception origin including those that result from maternal exposure to environmental agents [teratogens] such as alcohol, rubella, syphilis, and iodine deficiency that can harm the developing fetus . Thus, an estimated 9 million infants–representing approximately 7% of births-are born annually with defect that may kill them or results in lifelong disability . An estimated 270,000 newborns die during the first 28 days of life every year from congenital anomalies . Ninety-four percent of children with birth defects are born in low-income countries and 95% of those who die as a result of birth defect also born there . Accurate data of prevalence of congenital fetal anomalies rare. Data is usually obtained from registries of congenital anomalies and this indicates that congenital anomalies are seen in 2–3% of newborns which is similar to what is seen in the industrialized world . Congenital anomalies account for 8–15% of perinatal deaths and 13–16% of neonatal deaths in India . Reliable data from low-income countries on fetal anomalies like data from other health indices is difficult to come by and even where available it is generated from institutional studies rather than from population based studies. Yet most congenital anomalies and their severe consequences are seen in developing low-income. In developed countries common causes of perinatal and neonatal have been dealt with and congenital anomalies are now seen as causes of perinatal and neonatal death. In developing countries, the reverse is the case and this may be the reason why the contributions of congenital anomalies in perinatal and neonatal mortality is well appreciated. So the augment goes in view of the presence of commoner causes of perinatal and neonatal mortality it will not be appropriate to allocate resources trying to reduce mortality from congenital anomalies. The is question now is, can we wait to achieve health transition in which common causes of perinatal and neonatal mortality are eliminated before addressing the issue of congenital anomalies and their contribution to perinatal and neonatal mortality? The answer is no. What we fail to realize is in developing countries congenital anomalies indirectly contribute to maternal mortality. Imagine a situation where a pregnant woman goes in to labor with a fetus with an undiagnosed congenital anomaly that preclude vaginal delivery and as we know more than half of pregnant women in developing countries labor and deliver at home. In this scenario the labor be prolonged and with time obstructed, membranes would have ruptured, chorio-amnionitis would have set in and as consequence develop postpartum hemorrhage or puerperal sepsis and die or she develop ruptured uterus and die. Congenital fetal anomalies can lead to both perinatal and maternal mortality and morbidity.
In this chapter, I will discuss congenital anomalies, their causes, prenatal diagnosis, treatment and prevention with the peculiarities of the African environment in view.
Multitudes of factors determine the overall quality of health and pregnancy safety and outcome in Africa.
Illiteracy and poverty are factors that directly or indirectly influence health and pregnancy outcome in Africa. In Sub-Saharan Africa proportion of workers living in extreme poverty is 57% . Other factors are ignorance, superstitious beliefs, bad cultural practices and poorly developed health infrastructure. The rate malnutrition in Sub-Saharan Africa is 23% . In many countries in Africa utilization of antenatal care services is low and it is at this critical time pregnant women are screened for various diseases and ultrasound screening is done for fetal anomalies. In Nigeria only 2/3 of pregnant women attend antenatal care and only 40% deliver under the care of skilled birth attendants . Utilization of the antenatal and delivery services in other African countries is much lower. Sub-Saharan Africa has the lowest contraceptive prevalence 13% and highest unmet need for family planning 28% . Infections and infestations, lack of immunization against diseases that may be harmful to pregnancy and exposure to various potentially harmful substances increase the risk for fetal anomalies in Sub-Saharan African women. Lack of reliable data collection and recording means that the prevalence of congenital anomalies in the region is based on institutional estimates not the actual numbers. This is the background to understanding the causes, management and prevention of congenital anomalies in Africa. It is with this background in mind that this chapter will discuss the causes, management and prevention of congenital anomalies in Africa.
3. Causes of congenital anomalies
Fifty percent of birth defects have no clear identifiable cause and in the other 50% there are factors that considered as the cause. The causes can be broadly classified in to 3:
Birth defects of unknown cause (Table 1)
|Single gene disorders||7.5|
The pre-conception causes of birth defects are those causes that have their origin before conception and are genetic or partly genetic in origin [Genes and Chromosomes]. They found in families and can be inherited e.g. Sickle cell disease. They can also be seen as isolated incident in a particular pregnancy. The post-conception causes of birth defects are those anomalies that arise after conception or but before parturition. The last category of birth defects are those whose cause is unknown. The prevalence of birth defects based on the cause as shown in the above table is a broad division based on what is found in developed countries. If population based studies are conducted the findings differ from those above. This is because in developed countries concerted efforts were made to reduce environmental exposure to teratogens in pregnancy, institute preconception care to optimize medical conditions before pregnancy, immunize against infections that may affect the fetus in utero, offer pregnancy termination to where anomalies are identified etc. These measures reduce the prevalence of congenital anomalies of genetic origin or environmentally induced. In Africa environmental factors may play a role in causing birth defects. These may be from diseases [Viral, Bacterial and Protozoan/parasitic] or from exposure to teratogens [Alcohol, Cigarette, Pesticides and traditional medications who chemical constituents are unknown]. There is a difference in the annual numbers of birth defects, annual deaths from birth defects and annual under-5 deaths between Low-income, Middle-income and High-income countries. This is a demonstration of the impact of strategies put in place to control birth defects based on the level of economic development and investments made in health care infrastructure and health care provision and prevalence of modifiable risk factors for birth defects (Table 2).
|Low-income countries||Middle-income countries||High-income countries||Total|
|Annual total birth defects (millions)||4.75|
|Annual early deaths of birth defects (millions)||2.38|
|Annual under-5 deaths (millions)||8.8|
4. Chromosomal abnormalities as cause of birth defects
These account for 6% of birth defects in developed countries in industrialized countries . The most common example of is Down syndrome which is characterized by an extra chromosome and is also called trisomy 21. This is condition is now diagnosed early [Thickened Nuchal translucency, absent or hypoplastic nasal born etc.] and pregnancy can be terminated. Other defects in this category include Edward’s syndrome and patau syndrome. Many infants are born with Down syndrome in Africa because early diagnosis and termination is not possible. Lots of resources are expended by families and communities on caring for the affected infants which constitute a burden for the family.
Single gene defects an estimated 7.5% of birth defects . They are caused by alteration gene structure and more than 6000 single gene defects were described.
Environmental factors as cause of birth defects.
5. Drugs and birth defects
Drugs of various types are known to cause congenital birth defects. In Africa most drugs are bought over the counter as there are strict regulations. Because of poverty low medications are preferred by patients and such drugs may have potential side effects including embryo toxicity. As most pregnancies are unplanned women on treatment for some medical conditions may become pregnant and continue taking treatment with drugs that are teratogenic to the fetus. As antenatal care patronage is low women on such drugs may not be discovered until damage has been. Diseases requiring drug treatment either singly or in combination are common in Africa, ranging from infections, endocrine diseases such as diabetes and thyroid diseases, haemoglobinopthies, Epilepsy, leprosy, etc.
Drugs such as Phenytoin and sodium valproate are known to cause birth defects.
7. Deficiencies of essential elements and vitamins
Malnutrition as stated earlier is an important problem in African communities. Most of the essential elements are needed for normal fetal development. Malnourished women of reproductive age may lack these essential substances and could be at risk having babies with various forms of birth defects. An important vitamin whose deficiency leads to birth defect is folic acid and has been implicated as a cause of neural tube defect. Its use as a supplement in the preconception period and early pregnancy has been shown protect development of neural tube defects. Iodine deficiency is also implicated as a cause of birth defects [Iodine Deficiency Disorder characterized by intellectual disability motor and auditory disabilities] The severity depends on the level of deficiency in the mother. In 1998, an estimated 60,000 babies were born worldwide with severe iodine deficiency disorder (Cretinism), and an estimated 28 million pregnancies were still at risk of less severe Iodine-deficiency disorder from maternal iodine deficiency .
It provides an opportunity to classify the anomalies into lethal [e.g. Anencephaly, Bilateral renal agenesis] and non-lethal [e.g. Cleft lip, Polydactyl]
Surgically correctable and non-surgically correctable
It helps to identify those defects that are amenable to intra-uterine surgery and those that can be managed postnatally.
It helps decide when best to deliver, how to deliver and where to deliver
It provides us with a window to counsel the parents on the nature of the defect, treatment options and prognosis and thus assist them make an informed choice.
Where management is not available at the facility where diagnosis made, appropriate and timely referral can be made.
Prenatal diagnosis is testing for disease or condition in a fetus before it is born . The aim of prenatal diagnosis is to detect birth defects which can morphological, genetic or biochemical. It involves different processes and it can be broadly classified in two, invasive and noninvasive. The invasive test requires taking fetal tissue which could be blood [Cordocentesis], placental tissue [Chorionic villus sampling] and amniotic fluid [Amniocentesis]. The non-invasive tests involve the use of ultrasound to image the various structures of the fetus to identify the normal or the abnormal. Ultrasound thus detects morphological aberrations [e.g. gastroschisis, omphalocele, anencephaly], or serve as a means of getting access to fetal tissues for further testing [CVS, Fetal amnio and Cordocentesis]. With further advancement in scientific techniques non-invasive test can now be done on maternal blood [Harvesting fetal cells in maternal blood and subjecting them to genetic testing]. In Africa prenatal diagnosis and screening for congenital defects is at the stage of infancy as the personnel and facilities are few and in most places non-existent, where available accessibility and affordability becomes an issue (Table 3).
|Urban Area Rural Area|
|Geographical area||One examination||≥ 3 examinations||One examination||≥ 3 examinations|
Prenatal diagnosis has positively impacted on our knowledge of congenital anomalies that is why it is essential even in low-income countries. Prenatal ultrasound diagnosis of congenital defects is one of the black points of African ultrasonography . Ultrasound as an instrument for prenatal diagnosis is now available in many African countries but its application in prenatal diagnosis still faces a lot of challenges. The number of congenital defects diagnosed is very low and nearly always late in pregnancy . This does not provide opportunity for meaningful and timely interventions. As there are no established screening programs in Africa, diagnosis of congenital defects is opportunistic and happens by chance. Malformation detection rates do not exceed 20% [34, 35, 36] (Table 4).
|Geographical area||North Africa||Sub-Saharan Africa||Southern Africa|
8. Reasons for the challenges
Poorly trained/untrained service providers
Lack of ultrasound facilities in rural Africa where the bulk of the population reside
Absence of dedicated screening programs for congenital anomalies
Absence of laboratories for genetic and chromosomal analysis
Accessibility and affordability are important issues even where the services are available
In general, prenatal diagnosis for congenital anomalies is opportunistic and most often it happens by chance. Because of wide spread poverty the largest proportion of pregnant women are excluded from the opportunity.
9. Management of prenatally diagnosed congenital anomalies in Africa
Management/Treatment of any clinical condition including congenital anomalies is hinged on accurate and reliable diagnosis. Accurate diagnosis requires well trained personnel and appropriate equipment. A comprehensive management will also require the services of different specialists [Obstetricians, Neonatologists, Pediatric surgeons, special care nurses trained in care of infants with congenital anomalies]. These are all hard to come by in Africa. People generally recognize gross physical anomalies, hidden anomalies are not appreciated before birth [e.g. Cardiac anomalies]. It is only when the child is born and start manifesting with clinical symptoms that the parents will appreciate the problem. When a child is born with gross anomalies such anomalies may be associated with some syndrome. When the gross anomaly is corrected the genetic syndrome problem will remain and will manifest itself. Parents will attribute the manifestations of the genetic syndrome to metaphysical causes. It is thus difficult to make them understand the real cause and the possible remedy. As facilities for genetic/chromosomal analysis are few and in most cases non-existent it becomes difficult to make comprehensive evaluation and diagnosis. This makes final decision on management extremely difficult for the physician in Africa. Such is the environment perinatologists practice in Africa.
In this circumstance management of congenital anomalies cannot comprehensive and will be provided in a scattered manner. Often times when an anomaly is diagnosed treatment is limited to pregnancy termination where the laws allow. In one hospital 65% of pregnant women request for pregnancy termination when an anomaly is found in their fetus. In those with distressing polyhydramnius intermittent aspiration of the amniotic fluid is done to relieve the distress. Women who present with obstructed labor and a dead congenitally malformed fetus with hydrocephalus, delivery can be effected by craniotomy. For those that present with ruptured uterus, laparotomy is done and further management will depend on the extent of the rent and the clinical state of the fetus. Few countries [e.g. Egypt and South Africa] have centers that offer prenatal screening, diagnosis, treatment and follow up services, however such centers are not within the reach of the poor who carry most of the burden of congenital anomaly.
10. Illustrative cases
The cases below illustrate how pregnant women with undiagnosed fetuses with congenital anomaly will labor at home and developed ruptured uterus and present for treatment. All these cases presented with ruptured uterus following various interventions at home.
10.1 The way forward: collaborative care
This approach will require pooling of resources [Manpower, Equipment and other resources] to create referral hospitals in different countries and regions to serve as one stop shop able to provide care in all aspect of management of fetal congenital anomalies. Government, the private sector, philanthropists and other non-governmental organization can come together to establish such centers. Examples abound where similar collaboration has provided opportunity for treatment of some medical diseases requiring specialized care. The cardiothoracic center in Accra Ghana is now a regional center for referral that offer treatment for patients from different countries in West Africa as well as provide training for resident doctors from the whole sub-region. The first renal transplant at Aminu Kano Teaching Hospital was sponsored by philanthropist who also invites specialists from Britain and today thank to that effort the hospital is a referral and training center in renal transplant. In the management of congenital fetal anomalies similar approach can be adopted. The collaborative care group that I established at Abubakar Tafawa Balewa University Teaching Hospital Bauchi while I was there had achieved some success. We educated the community, Counsel parents, managed some pregnancies complicated by congenital anomalies and surgically treated a few cases despite the challenges we had. This can be replicated in other teaching hospitals.
11. Preventing birth defects: which approach?
The prevention of birth defects in Africa should be modified from the traditional approach that is adopted in other regions of the world. This is because of the peculiarities of the African environment. As much as possible all preventive strategies should be simple, low cost and innovative. All stakeholders must be involved, governments, communities, professional societies dealing with the issue, and non-governmental organizations. First stage should involve educating policy makers with emphasis on the burden of the problem on families and society at large. Educating policy makers on the need to understand how congenital anomalies contribute to both maternal and perinatal mortality. Areas that will require government intervention especially in community education, training of personnel and provision of equipment. Involving traditional and religious leaders who are gate keepers, educating them on the causes and prevention of birth defects. Involving the media in community enlightenment through discussion programs, talk shows and jingles.
Even as we want evolve our own model of prevention based on our peculiar social, environmental and economic circumstances, we must learn lessons from the experiences of other countries such as Cuba, China, India and Brazil. We must extract some of elements in the model they used and input them in to our own model. As we develop our preventive strategies we need to have the following at the background for us to succeed:
Endemic poverty and illiteracy
Uncontrolled birth rates and poor uptake of family planning services
Malnutrition and micronutrient deficiencies
Poor uptake of immunization services
Loose control of drugs and substances which are known to be teratogenic
Customs and traditions which are harmful to health
Our goal is to eliminate causative factors of congenital defect
Emphasis should be on primary prevention as we prepare to introduce secondary and tertiary prevention.
This is background to discussing the strategies for the prevention of congenital anomalies in Africa.
First strategy is education which is the backbone of development and progress in all spheres of life. It is known that the higher the level of literacy of a community the better are its economic indices, social status and health seeking behavior of its members. Education may be crucial in understanding the causes, treatment options and methods of prevention of congenital anomalies. It will also go along way in eliminating traditional and cultural practices that put communities at risk for congenital anomalies.
12. Specific measures
Targeted screening can be offered to the following category of pregnant women;
Women with; Previous history of babies with congenital anomalies, history of congenital anomaly in the family, index pregnancy with polyhydramnious, age more than 35 years, multiple gestation, consanguineous marriage, diabetes and those with sickle cell disease/Thalassemia.
Birth defects or congenital anomalies are important cause of perinatal mortality and morbidity. In developed countries successes were achieved in screening, treatment and prevention over the years. In Africa the picture is different as many factors play a role in causing congenital anomalies different from those seen in developed countries. In Africa factors such as poverty, illiteracy, malnutrition, exposure to teratogens and poor environmental control play an important role. Screening, treatment and preventive services for congenital anomalies are poorly developed. To achieve control primary prevention should be established and strengthened and when this is achieved, then secondary and tertiary control should follow. Innovative strategies should be employed in this endeavor.