In a woman’s uterus, the fertilization as well as the development of either one or more off-springs called as embryo or foetus is called pregnancy. Pregnancy may also be defined as the fertilization of an egg in the woman’s Fallopian tube after ovulation (the matured egg released from one of the woman’s ovaries) due to the penetration of a male sperm. A sperm in all has 23 chromosomes that include either x–chromosome or y–chromosome (X and Y chromosomes are the two types of sex chromosomes). Fertilization of an egg due to a sperm having x – chromosome produces a girl, whereas fertilization of an egg due to a sperm having y-chromosome produces a boy. As a sperm, each egg also consists of 23 chromosomes. To make a human, 46 chromosomes are required. When a sperm and an egg fuse together, each having 23 chromosomes, the chromosome count becomes 46, which is required to make a human being.
After fertilization, the fertilized egg is called a zygote. Soon after fertilization, the zygote starts dividing itself and continues till a cluster of cell is formed. Villi (root like veins) are put out, when the divided cells attach themselves to the uterus wall (womb), after the continuous division of the zygote. The cells are known as an embryo. The villi ensure that the embryo gets attached to the uterus lining. The villi eventually get transformed into the placenta, which protects and provides food for the embryo/foetus.
There may be multiple gestations (carrying of embryo/foetus), in the pregnancy of a woman, as in the case of twins or in the case of triplets. Usually after 38 weeks of conception, childbirth occurs. Conception is achieved through either sexual intercourse or assisted reproductive technology like IVF (in vitro fertilization).
Following the first eight weeks after conception, the developing off-spring is called as embryo whereas subsequently, till childbirth, the term foetus is used. Human pregnancy is divided into three trimester periods in many societies’ legal and medical definition. High risk of miscarriage (natural death of the foetus/embryo) is carried in the first trimester. The development of the foetus can be easily monitored during the second trimester. The ability of the foetus to survive without or with medical aid outside the uterus can be determined at the start of the third trimester. In the United Kingdom and the United States, 40 percent of the pregnancies are unplanned. In the 40 percent of the unplanned pregnancies, quarter and a half are unwanted. 60 percent of the women use birth control to an extent, during the conception month.
SYMPTOMS: Most of the pregnant mothers show the following symptoms:
- Craving for certain special foods that are not often sought for.
- Frequent urination during night.
Certain medical symptoms may also be shown by the pregnant mothers. They are as follows:
- Presence of hCG (human chorionic gonadotropin) in the urine and blood.
- Bleeding due to the embryo implantation, in the third or fourth week after the last menstrual period, in the uterus.
- Chadwick’s sign (darkening of vagina, vulva and cervix).
- Goodell’s sign ( vaginal portion of the cervix being soft).
- Breast tenderness.
COMPLICATIONS: According to W.H.O, more than 20 million women of the entire world, experience ill-health due to pregnancy. Lives of eight million women are threatened and in the year 1995, more than, 500,000 women are estimated to die due to the causes related to childbirth and pregnancy.
Pregnancy causes many levels of health risk for women, as per their medical profile, prior to pregnancy. Few complain, which may occur during or after pregnancy, because of the changes that occur in a woman’s body, due to pregnancy. They are as follows:
- Hypertension induced due to pregnancy.
- Pain in back.
- Urinary Tract Infection.
- Varicose vein.
- Postpartum depression.
- Postpartum psychosis.
RECOMMENTAIONS: Drugs that are used at the time or during pregnancy may have permanent or temporary effects on the foetus. Hence, many physicians prefer not to prescribe for pregnant women, due to the concern being over teratogenicity (Abnormality that may cause to the foetus) of the drugs.
The drugs are classified into A, B, C, D and X categories according to the rating system provided by the Food and Drug Administration (FDA), for providing guidance on the foetal risks and potential benefits. Some drugs including some multivitamins having no foetal risks as per the controlled studies in human are put in category A whereas drugs like thalidomide with proven foetal risks are put in category X.
From the above, it is imperative that during pregnancy and after pregnancy, a competent medical advisor should be in regular contact with the pregnant women.