**5. Drugs and birth defects**

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

*Estimated numbers and percentage of annual total birth defects, early deaths due to birth defects, and under-5*

**Low-income countries**

*Congenital Anomalies in Newborn Infants - Clinical and Etiopathological Perspectives*

4.75 60%

2.38 72%

80%

**Middle-income countries**

> 2.64 34%

> 0.79 24%

1.8 16% **High-income countries**

> 0.49 6%

0.14 4%

> 0.6 4%

**Total**

7.9

3.3

11.2

These account for 6% of birth defects in developed countries in industrialized countries [11]. 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

Single gene defects an estimated 7.5% of birth defects [11]. They are caused by alteration gene structure and more than 6000 single gene defects were described.

**Bacterial infections**: Example, Syphilis which in Sub-Saharan Africa is seen 6– 16% of pregnant women [12]. Currently most countries in Africa screen for Syphilis during antenatal care and provide treatment for those affected. Those affected present with features of the disease in the first 3 months of life which include; Vesiculobullous eruptions or macular copper-colored rash on the palms and soles and popular lesions around the nose and mouth as well as petechial lesions.

**Protozoan infection:** Congenital toxoplasmosis occurs as a result of maternal vertical transmission to the fetus. It is a cause of severe fetal complications that may manifest in the early neonatal period but may manifest later and lead to life-long complications. Diagnosis is through laboratory tests, however ultrasound is helpful and can be used to assess prognosis. The classical triad of congenital Toxoplasmosis

**Viral infections:** Many viral infections are implicated as cause of several birth defects. Some viral diseases present with non-specific clinical features and many other infections have similar features. In Africa with poor health infrastructure screening and diagnosis for most diseases is challenging. Thus viral diseases may affect pregnant women and cause fetal congenital anomalies which may not in the

are; chorioretinitis, hydrocephalus and intracranial calcifications.

**4. Chromosomal abnormalities as cause of birth defects**

risk factors for birth defects (**Table 2**).

Annual under-5 deaths (millions) 8.8

*deaths for low-, middle-, and high- income countries.*

Annual total birth defects

Annual early deaths of birth defects (millions)

(millions)

**Table 2.**

*MOD [3]; UNICEF 2001.*

infants which constitute a burden for the family.

**Intrauterine infections;**

**200**

Environmental factors as cause of 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.

**Misoprostol:** This is common drug used to induce abortion and is cheap, readily available and is sold over the counter in most African countries. Girls who have unwanted resort to its use without recourse to doctor's prescription. In approximately 80% of cases it fails to induce abortion and the pregnancy continue to term [14]**.** Misoprostol even though of low teratogenicity it is known to cause facial nerve paralysis, with or without limb defects, probably due to vascular disruption of the subclavian artery and an ischemia in the embryonic brain stem [15–17].
