CHAPTER ONE 1.0 INTRODUCTION Pregnancy is defined as the period from conception to birth(Dorland’s medical dictionary, 2012). It is also referred to as gestation period, during which there is an embryo developing in the uterus and it could be a single embryo or multiple embryo(Abman, 2011). In humans, it usually lasts around 40weeks from the last menstrual period and ends in childbirth(ACOG, 2013). Pregnancy begins with conception, the process of fertilization of the female egg by the male spermatozoa. The fertilized egg starts dividing fast into many cells. It keeps dividing as it moves slowly through the fallopian tube to the uterus where it gets attached to the endometrial lining where it begins to form thefetus and placenta. This attachment to the endometrial linningis known as implantation(Sadler, 2011). Pregnancy is divided into three trimesters(Moore and Persaud,2003); First trimester; This period spans from 0-12wks(Sohaey et al., 1996). During this period, hormone levels change significantly, placenta and fetus growth is supported by the uterus, heart rate and blood supply increases to meet the needs of the growing fetus(Demianczuck and Van, 2003). These changes accompany many of the pregnancy symptoms such as fatigue, morning sickness, nausea, vomiting, headache and constipation(Festin, 2014). The first trimester is very crucial to the development of the baby. The fetus will develop all its organs by the end of the third month(Rosenblatt et al., 1996). Adequate nutrition and food supplementation is necessary(Kaiser et al., 2008). Alcohol abuse, cigarette smoking, undue ingestion of drugs and abusive substances have all been related to serious complications and birth defects(Aaranson and Macnee, 1989, Ness et al., 1999). In rats, the gestation period is about 21days and the first trimester corresponds today 1-7(Karen, 2006). Second trimester; This period spans from13-28wks(Ecker and Green, 2006). During this period, uterus increases in size, maternal weight gain, fetus increases in size, fetal movement starts. Screening tests are usually done at this time(Hurt, 2011). This period corresponds to days 8-13 in rats(Karen, 2006). Third trimester;This trimester lasts about 29-40wks. At this time, final weight gain takes place, fetal engagement with reduction in bladder capacity and increase in pressure on the pelvic floor and the rectum(Seeds, 1996). In rats, the third week corresponds to the third trimester. During this period, the mammary gland develops maximally with the uterus developing a lot of blood vessels (Lindsey, 2004). Each year, an estimated 123million women get pregnant worldwide, about 46million get terminated(WHO, 2004). Complications that can arise in pregnancy include the following; abortion, maternal bleeding, maternal sepsis, anemia, ectopic pregnancy, fetal intrauterine growth retardation, intrauterine fetal death(ACOG, 2011). WHO estimates that 4billion people, i.e 80% of the world population, use herbal medicine for some aspect of primary health care (Farnsworth et al, 1985). It also suggested in improving the technologies for cultivation of medicinal plants.
Investigations across the world confirm dramatic increment in the use of complementary and alternative medicine in pregnant women. Most pregnant women believe that these medicines are natural and safe compared to modern drugs.