**1. Introduction**

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 [1]. Every year, an estimated 7.9 million children are born with serious birth defects of genetic or partly genetic origin [2]. 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 [3]. 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 [4]. An estimated 270,000 newborns die during the first 28 days of life every year from congenital anomalies [5]. 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 [6]. 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 [7]. Congenital anomalies account for 8–15% of

perinatal deaths and 13–16% of neonatal deaths in India [8]. Reliable data from lowincome 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.

**3. Causes of congenital anomalies**

*DOI: http://dx.doi.org/10.5772/intechopen.91994*

• Birth defects of unknown cause (**Table 1**)

classified in to 3:

• Pre-conception

• Post-conception

**Pre-conception**

**Post-conception**

*Ternpenny and Ellard [11].*

*Percentage of birth defects by cause in high income countries.*

**Table 1.**

**199**

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

*Fetal Congenital Anomalies in Africa: Diagnostic and Management Challenges*

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.

**Cause %**

Chromosome disorders 6 Single gene disorders 7.5 Multifactorial 20–30 **Subtotal** 40

Teratogens 7–8% Intrauterine abnormalities 2 **Subtotal** 10 Unknown cause 50 **Total** 100

In this chapter, I will discuss congenital anomalies, their causes, prenatal diagnosis, treatment and prevention with the peculiarities of the African environment in view.
