CHAPTER ONE 1.1 Background Hypertension during pregnancy is the most common condition encountered, complicating about 2-3% of pregnancies worldwide. This makes it a common cause of both foetal and maternal mortality, accounting up to 10-15% of cases of maternal mortality in developing countries.In Africa, this affects about 10% of all pregnancies, particularly affecting women from urban areas compared with those from rural areas.In the United Sates, there is approximately one maternal death due to preeclampsia-eclampsia per 100,000 live births, with a case-fatality of 64 per 100,000 cases. Hypertension can be classified as systolic blood pressure over 140mmHg, diastolic greater than 90mmHg. Hypertension during pregnancy could be classified as; · Chronic hypertension – this is hypertension in a patient who was diagnosed with the condition prior to becoming pregnant and could have lived with the condition for a number of years. It could also be defined to hypertension diagnosed before 20 weeks of gestation, i.e., undiagnosed chronic hypertension that makes itself apparent with the advent of the pregnancy. It could also be defined as hypertension persisting after more than 12 weeks postpartum. Its estimated prevalence in the United States is about 3%. (EW Seely, 2011) · Gestational hypertension – this is hypertension that is diagnosed after 20 weeks gestation, with the blood pressure being measured on two separate occasions more than six hours apart, without the presence of protein in the urine. (Abrams et al, 2011) this is expected to complicate about 6% of all pregnancies, with 15-45 % developing preeclampsia. (GK Davis,2007)