BIOLOGY CLASS NOTES FOR CBSE Chapter 04. Reproductive Health 01. Introduction Reproductive health refers to healthy reproductive organs with normal functions. However, it has a broader perspective as it involves well-being reproductive health means well being in physical emotional behavioral and social aspects of reproduction. Therefore, reproductively, to a healthy society of people having physically and functionally normal reproductive organs and normal emotional and behavioral interactions and among them in all sex-related aspects.
Reproductive Health Problems and Strategies (i)
(ii)
(iii) (iv)
(v)
(vi)
(vii)
Over population : The main problem of India is its excessive population is directly connected with reproductive health To achieve total reproductive health, some plans and programs were started Family planning program was started in 1951 in India and was periodically assessed over The major tasks carried out under these programs are to provide facilities and support for building up a reproductively healthy society. Awareness about reproduction : Audio-visual and print middle government and non-governmental agencies are doing a good job to create awareness among people about reproduction in humans. Sex Education : Sex education in schools should also be introduced and encouraged to provide right information about myths and misconceptions about sex-related aspects. knowledge of growth of reproductive organs and STDs : proper information about reproductive organs, adolescence (period of rapid growth between childhood and adulthood), safe and hygienic sexual practices sexually transmitted diseases (STDs), e.g., Aids etc., would help to lead a reproductively healthy life. Birth control devices and care of mother and child : Fertile couples and people of marriageable age group should know about available birth control devices, care of pregnant mothers, postnatal (after birth) care of the mother and child, importance of breast feeding, equal importance for the male and female child, etc. Prevention of sex abuse and sex related crimes : Awareness of problems due to uncontrolled population growth, social evils like sex abuse and sex-related crimes, etc. need to be created so that people should think and take up necessary steps to prevent them and thereby build up a reproductively healthy society. Amniocentesis – Meaning and use : Amniocentesis is a foetal sex and disorder determination test based on the chromosomal pattern of the embryo’s cells in the amniotic fluid surrounding the developing embryo.
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Procedure : Amniotic fluid contains cells from the skin of the foetus and others sources. These cells can be used to determine the sex of the infant, to identify some abnormalities. in the number of chromosomes and to detect certain biochemicals and enzymatic abnormalities. If it is established that the child is likely to suffer from a serious incurable congenital defect, the mother should get the foetus aborted. Misuse of Amniocentesis : it is being misused to know the sex of unborn baby followed by medical termination of foetus, in case its female.
NOTE ☞
Recent studies have discovered that amniotic fluid can be a rich sources of multipotent mesenchymal, hematopoietic, neural, epithelial and endothelial stem cells.
(viii) A Research in reproductive health area : it should be encouraged and supported to find out new methods. “Saheli” a new oral contraceptive for the females was by our scientists at central Drug Research Institute (CDRI) in Lucknow, India. (ix) Medical facilities : Better awareness about sex related problems, prenatal care of mother, medically assisted deliveries and post natal care of mother and infant decrease maternal and infant mortality. Small families, better detection and cure of sexually transmitted diseases (STDs) and increased medical facilities for sex-related problems, etc. indicate improved reproductive health of male and female individuals and children.
Measures to Control Over Population (a) Education : people, particularly those in the reproductive age group, should be educated about the advantage of a small family. Mass media and educational institutions can an play important role in this campaign. (b) Marriageable Age : Raising of the age of marriage is a more effective means to control the population (now marriageable age of female is 18 years and that of male is 21 years). (c) Incentives : Couples with small families should be given incentives. (d) Family planning : There are many birth control measures which can check birth rate.
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02. Human Population Growth Human population growth is measured as the annual average growth rate which is calculated as follows: P P Average annual growth rate (in percent) = × P ×N where, P1 is population size in the previous census; P2 is population size in the present census: and N is numbers of years between two census. Census gives information about the number of individuals present in a given region at a given time. The time required for a population to double itself is called the doubling time. The present growth rate of approximately 1.7 percent per year (individuals per 1000 of population) for india is smaller then the peak of about 2.1 percent per year during 1965-1970. Population growth rate is indicated by (i) the annual average growth rate and (ii) the doubling time. Growth rate depends on birth (fertility) rate, death (mortality) rate, migration and age sex ratio. Fertility (Natality) : Fertility is the ability of the reproductivity active individuals to produce babies. Birth rate is the number of babies produced per thousand individuals. It differs form the population growth rate as it is never negative while the growth rate can be negative. Total fertility rate (TFR) is the average number of children that can born to a women during her lifetime. The more developing countries have lower fertility rate than the less developed countries. Fertility is mainly controlled by economics and human aspirations. Replacement level (RL) is the number of children a couple must produce to replace themselves so as to maintain the population at zero growth level. RL is sightly higher then 2.0 because some children die before reaching reproductive age. RL is 2.1 in devloped countries and 2.7 in developing countries due to a higher death rate at immature age. (ii) Mortality : Mortality is the death rate per thousand individuals. death rete has fallen in most countries. It is due to improve personal hygiene, sanitation and morden medicines. Demographers generally use crude birth rate and crude death rate. Crude birth rate is the numbers of live births per thousand persons in the middle of a given year (i.e., on July 07) The difference between the numbers of births and that of deaths is called the rate of natural increase. If birth and death were equal a zero population growth rate would result is known as demographic transition. (i)
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Age and Sex Structure : The age structure of a given population of individuals of refers to the proportion of individuals of different ages within that population. The aspect is important because many functional aspects of the individuals are related to age. For example infants blow one year of age and the older people have higher mortality rate than individuals of others ages. In addition, the proportion of reproductivity active males and female in a population influences the population growth. The numbers of female individuals in active reproductive age (usually 15-44 years) influences the birth rate within a population. Age-sex structure of a population can be depicted in the form of a pyramid diagram by plotting the percentage of population of each sex in each age. Figure shows the age-sex pyramid for the developed and developing countries for the years between 1975 and 2000. The age sex-sex structure of the developed would gives a steeper pyramid, which represents a nearly stable population. In contrast, a rapidly growing population. like that of india is represented less steep pyramid, as it has a much larger number of younger people. The female side of the diagram is particularly important in understanding future growth.
03. Contraceptives They are the devices which prevent conception or pregnancy without interferring in the reproductive health of the individuals in any way. Characteristics of an ideal contraceptive are: (i) User friendly, i.e. comfortable and easy to use. (ii) Absence of side effects. (iii) Reversible, i.e. when the user wnts to conceive, it should be easy to be interrupted. (iv) Completely effective against pregnancy. There are several methods of contraception-natural of traditional, barries, IUDs, oral contraceptives, injectables, implants and surgical methods. Couple protection is the process of bringing eligible couples under family planning measures. In India, it is over 55% at present and is voluntary in nature. In 2004, there were 60-79 lakh IUD insertions, 48-74 lakh sterilisations or surgical interventions, 249-9 lakh condom users nd 87-54 lakh oral pill users. (a) Natural Methods : They are the methods which do not require any device, medicine or religious sanction. Natural methods are of three kinds-safe period, withdrawal and breast feeding. (i) Safe period (Rhythm Method) : Ovulation occurs roughly about the middle of menstrual cycle. Fertility period when fertilisation can occur is upto 24 hours after ovulation. Avoiding sex during the fertility period will naturally prevent conception. Ovulation period can be known as the basal body temperature rises by about 1oF during ovulation. Cervical mucus is slippery abundant, stretchable due to influence of estrogens. Period prior to ovulation is safe. Period after fourth day of rise in temperature (or last positive Spinnbarkeit test) is also considered safe. It is however, always better to avoid sex from day 10-17 of the menstrual cycle.
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(ii)
Withdrawal Method (Coitus Interruptus) : The method is based on withdrawal of penis before ejaculation. This method has a high failure rate due to pre-ejaculatory emission of sperms or failure to withdraw penis before ejaculation. (iii) Lactational Amenorrhoea : Just after parturition, there is a phase of amenorrhoea or absence of menstruation. It is also the phase of intense lactation. Breast feeding the child fully prevents conception. The method is however, effective only upto a maximum period of six months. (b) Barrier Methods : They are mechanical devices which prevent the deposition of sperms into vagina and their passage into uterus. Further, they can be self-inserted by the user in complete privacy. The common barrie methods are condoms, diaphragms, fem shields and cervical caps. (i) Condom : It is a tubular latex sheath which is rolled over the male copulatory organ during sex. The common brand provided by family welfare services is Nirodh. The device also provides protection against sexually transmitted diseases including AIDS. (ii) Fem Shield (Female Condom) : The device is a polyurethane pouch with a ring at either end. The inner ring is smaller and present at the inner closed end. The device covers the external genitalia as well as lines the vagina. (iii) Fem shield provides protection from sexually transmitted diseases also. (iv) Diaphragm : It is a tubular rubber sheath with a flexible metal or spring ring at the margin which is fitted inside the vagina. (v) Cervical Cap : It is a rubber nipple which is fitted over the cervix and is designed to remain there by suction. The device prevents the entry of sperms into uterus. (vi) Vault Cap : It is a hemispherical dome-like rubber or plastic cap with a hick rim which is meant for fitting over the vaginal vault over the cervix. (c) Chemical Methods : They are the contraceptives which contain spermicidal chemicals. The chemical contraceptives are available in the form of creams (e.g. delfen), jellies (perceptin, volpar paste), foam tablets (e.g. aerosol foam, chlorimin T or contab). They commonly contain lactic acid, boric acid, citric acid, zinc sulphate and potassium permanganate. The contraceptives are introduced in vagina prior to sex. Sponge (Today) is a foam suppository or tablet containing nonoxynol-9 as spermicide. It kills the sperm by disrupting the membrane. It is moistened before use to activate the spermicide. The device also absorbs ejaculate. (d) Intrauterine Devices (IUDs) (Intrauterine Contraceptive Devices or IUCDs) : The devices are made of plastic, metal or a combination of the two and are inserted into the uterus to prevent conception. IUDs are called loops, spirals, rings, bows, shields or Ts depending upon the shape. IUDs are of three types-inert, copper releasing and hormone releasing. The inert IUDs are made of polyethylene impregnated with barium sulphate or stainless steel e.g. Lippe’s loop. The exact mechanism of inert IUD contraception is not clear. (i) There is impairment of sperm ascent. (ii) There is quick tubal motility resulting in premature migration of fertilised eggs into uterus before it is ready for receiving it. (iii) Histological and biochemical changes in endometrium which have gametotoxic and spermicidal effect.
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Copper IUDs commonly called Copper-Ts have ionised copper which slowly diffuses at the rate of some 50 g/day. It has a local antifertility effect by bringing about release of toxic cytokines. They suppress sperm motility and their ability to fertilize the ovum. The device is to be replaced after 3-5 years when copper release becomes scanty due to calcium deposition. Cu T380A has a replacement period of 7-10 years. Copper IUDs are designated by the exposed surface area of copper in sq mm, e.g., Cu T 200, Multiload Cu T 250, Multiload Cu T 375, Cu T 380, Cu 7. Hormone releasing IUDs include progesterone IUD (e.g., progestasert) and levonorgestrel IUD (e.g., LNG-20). These devices release small quantities of hormones which suppress endometrial changes and changes in cervical mucus, cause anovulation and insufficient luteal activity. (e) Oral Contraceptives (Oral Pills) : They are preparation containing either progestin (progestogen or synthetic progesterone) alone or a combination of progestogen and oestrogen (estrogen). The pills are taken orally for 21 days in a menstrual cycle starting from 5th day and ending on 25th day. However, it is advisable to restart the course after a gap of 7 days, irrespective of the onset or nonset of menstruation during the pill free days. When a pill is missed, it should be taken whenever one remembers, sometimes two at time. (f) This helps in keeping the hormonal level required for contraception. Hormonal pills act by four ways (a) Inhibition of ovulation. (b) Alternation in uterine endometrium to make it unsuitable for implantation. (c) Changes in cervical mucus impairing its ability to allow passage and transport of sperms. (d) Inhibition of motility and secretory activity of fallopian tubes. Oral pills are of two types, combined pills and minipills. Combined Pills contain both oestrogen and progestin. They are synthetic products. Oestrogen is anovulatory (inhibits FSH production). Progestin is also anovulatory (inhibits LH production). It protects the endometrial lining from adverse effect of oestrogen. The hormone also changes cervical mucus. The most commonly used progestin is levonorgestrel or desogestrel. The most common oestrogen is ethinyl oestradiol or menstranol. In monophasic combined pill, both oestrogen and progestin are present in nearly the same amount, e.g., Mala D, Mala L. in multiphasic combined pills, oestrogen in maintained at the same level throughout the 21 day course. The amount of progestin is increased gradually e.g., triquilar, orthonovum. Minipills are progestin only pills (with no estrogen). It should be taken daily without break eg., POP Saheli, a nonsteroidal preparation, is taken once a week after an initial intake of twice-a-week dose for 3 months. (g) Injectable Contraceptives (Depo-Provera) : Two types of progestin preparation sare used singly. They are depot-medroxy progesterone acetate (DMPA) effective for three months and norethisterone enanthate (NET EN) effective for two months, Cyclofem and mesigna are combined injectable contraceptives which are given once every month. They contain progestin preparation as well as oestradiol.
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(h) Implants : They are hormone containing devices which are implanted subdermally for providing long term contraception. Norplant is progestin only device having six small silicone (permeable) capsules each having levonorgestrel. They are inserted under the skin in a fan shaped manner inside upper arm or forearm though a small incision. Suturing is not required. Norplant remains effective for about 5 years. Implanon is a single rod-like device which is implanted through a wide-bored needle. It contains 3-keto desogestrel (progestin). It remains functional for three years. (i) Emergency Contraception : It is the treatment for unprotected sex, sexual assault, missed pills and other reasons which risk of pregnancy. The drugs used for treating emergency contraceptions are called morning-after pills. They are also available in India under Family Walfare Programme since 2002-2003. Two ovral tablets to start and two, tablets after 12 hours provide relief. Other morning after pills are noral, norgynon and ovidon. An antiprogesterone pill (mifepristone) is a single pill treatment. Insertion of IUD within 72 hours of unprotected sex prevents implantation. (j) Surgical Methods of Family Planning : They are also called terminal methods of family planning. Surgical methods are permanent methods of family planning where there is no need of replacement or augmentation but the reversibility is poor. The methods are operative procedures which block the passage of semen in males and ova in females. The techniques are also called sterilisation procedures. They are called vasectomy in males and tubectomy in females.
Table-2 : Differences between Vasectomy and Tubectomy 1. It
is
Vasectomy the surgical
sterilisation 1. It
technique for the males. 2. Two two vasa deferentia
is
Tubectomy the surgical
sterilisation
technique for the females. are 2. Two two oviducts are interrupted by
interrupted by giving cuts. 3. Transport of sperms is blocked.
either ligation or cuts. 3. Transport of ova is blocked.
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Side Effects of Contraceptive Methods: Except the natural methods, all other contraceptive procedures are unnatural. Therefore, they must have some side effects like nausea, abdominal pain, breakthrough bleeding, irregular menstrual bleeding etc. Some even try to link breast cancer iwh them. However, the major cause of these discomforts is mental burden about accepting an artificial procedure for preventing unwanted pregnancy. The benefits are several times the side effects experienced by soe persons. Condoms protect the users from catching STDs, including AIDS. One or two children by a couple means a long and satisfying family life, happy reproductive health and well brought-up children. (k) Induced Abortion : Abortion refers to the premature expulsion of the conception products from the uterus, usually before the 20th week of pregnancy. An abortion may be spontaneous (naturally occurring), sometimes called a miscarriage or induced (intentionally performed). When birth control methods are not used or fail to prevent an unwanted pregnancy, induced abortion may be performed. induced abortions may involve vacuum aspiration(suction), infusion of a saline solution, or surgical evacuation (scraping). Certain drugs, most notably the French drug RU-486, can induce, a so-called nonsurgical abortion. RU-486 (mifepristone) is an antiprogestin; it blocks the action of progesterone. Progesterone prepares the uterine endometrium for implantation. If progesterone levels fall during pregnancy or if the action of the hormone is blocked, menstruation occurs and the embryo is sloughed off along with the uterine lining.
Medical Termination of Pregnancy (MTP) It is voluntary or intentional abortion, induced and performed to end pregnancy before the completion of full term. Worldwide, nearly 20% of the total pregnancies get aborted. The number of MTPs is 40-50 million/yr. Therefore. MTPs have a significant role in containment of population though they are not performed for this purpose. They are mainly meant for removing unsustainable pregnancies. Many countries do not have a law about MTPs because the latter involve emotional, ethical, religious and social issues. However, in India there is a proper act, Medical Termination of Pregnancy Act, 1971. It is mainly meant for preventing unnatural maternal deaths due to unsafe abortions (8.9% of the total maternal deaths). The act was amended in 2002. Under this act, termination of pregnancy can be done upto 20 weeks, if the pregnancy is likely to produce a congenitally malformed child, is a result of rape or contraceptive failure or is likely to harm the mother. MTP is safe if it is performed up to 12 weeks (first trimester) of pregnancy. Misoprostol (prostaglandin) along with mifepristone (antiprogesterone) is an effective combination. Vacuum aspiration and surgical procedures are adopted thereafter Second trimester abortions are risky. They are generally performed after testing the sex of the baby through amniocentesis or sonography. It has resulted in large scale female foeticide and complications due to unsafe abortions in the hands of untrained persons. To prevent such mis-happenings, the government has enacted a law, Pre-natal diagnostic techniques (Regulation and Prevention of Misuse) Act, 1994 with amendments in 2003. It prohibits preconception and prenatal sex determination.
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NOTE ☞
Methods under research For Females : Ÿ Praneem is a polyherbal vaginal tablet being studied in India as a spermicide, and a microbicide active against HIV. Ÿ Buffer Gel is a spermicidal gel being studied as a microbicide active against HIV. Ÿ A longer acting vaginal ring is being developed that releases both estrogen and progesterone, and is effective for over 12 months. For Males : Ÿ RISUG (Reversible Inhibition of Sperm Under Guidance) is an experimental injection into the vas deferens that coats the walls of the vas with a spermicidal substance. The method can potentially be reversed by washing out the vas deferens with a second injection.
04. Sexually Transmitted Diseases The general term sexually transmitted disease (STD) is applied to any of large group of diseases that can be spread by sexual contact. The group includes conditions traditionally specified as venereal diseases (VD), such as chlamydia, gonorrhoea, syphilis, and genital herpes. AIDS and hepatitis are sexually transmitted diseases that may be contracted by other ways also. STDs are also called RTI (Reproductive tract infections). Except for hepatitis B, genital herpes and HIV infections, other STDs are completely curable if detected early and treated properly. Early symptoms include itching, fluid discharge, slight pain, swellings etc. in the genital region. Later complications include pelvic inflammatory disease (PID), abortions, still births, ectopic pregnancies, infertility or even cancer of the reproductive tract. Though all persons are vulnerable to these infections, but their incidences are high among persons in the age group of 15-24 years. (a) Chlamydia Causative agent : Chlamydia trachomatis. Chlamydia is a sexually transmitted disease caused by the unusual bacterium which cannot reproduce outside the body cells; it “cloaks” itself inside the cells to divide. In males, urethritis is the principal result. Symptoms of urethritis include a thick discharge, burning on urination, frequent and painful urination. Without treatment, the epididymis may also become inflamed, leading to sterility. In females, the most common site of infection is the cervix, resulting in cervicitis and production of a thick mucus and pus discharge. Symptoms include pelvic soreness, lower back pain and abdominal pain. Due to its proximity to the vagina, the female urethra may also become infected, leading to urethritis and symptoms similar to those that occur in males.
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Moreover, the uterine tubes may also become inflamed, which increases the risk of ectopic pregnancy (implantation of a fertilized ovum outside the uterus) and sterility due to formation of scar tissue in the tubes. Chlamydia may be passed from mother to infant during childbirth, infecting the eyes. Treatment consists of administration of tetracycline or doxycycline. (b) Gonorrhoea Gonorrhoea or “clap” is an infectious sexually transmitted disease caused by the bacterium Neisseria gonorrhoeae. discharge from infected mucous membranes is the source of transmission of the bacteria during sexual contact or during passage of a newborn through the birth canal. The site of infection relates to the type of sexual contact, occurring in the mouth and throat after oral-genital contact, vagina and penis after genital contactor rectum after recto-genital contact. Males usually suffer from inflammation of the urethra with pus and painful urination. The prostato gland and epididymis may also become infected. In females, infection typically occurs in the vagina, often with a discharge of pus. Both infected males and females may harbor the disease without any symptoms, however, until it has progressed to a more advanced stage. In females, the infection and consequent inflammation can proceed from the vagina into the uterus, uterine tubes, and pelvic cavity. Peritonitis or inflammation of the peritoneum, is a life threatening disorder. If the bacteria are transmitted to the eyes of a newborn in the birth canal, blindness can result. Administration of 1% silver nitrate solution in the infant’s eyes prevents infections. For many years, penicillin and tetracycline were the drugs of choice for the treatment of gonorrhoea in adults. However, bacteria strains resistant to these antibiotics have become very prevalent since the mid-1980s. Currently, ceftriaxone is the antibiotic that most effectively attacks the majority of gonorrhoea bacteria. (c) Syphilis Syphilis is a sexually transmitted disease caused by the bacterium Treponema pallidum. It is transmitted through sexual contact or exchange of blood or though the placenta to a fetus. The disease progresses through several stages. During the primary stage, the chief symptom is painless open sore called a chancre, at the point of contact. The chancre heals within 1-5 weeks. From 6 to 24 weeks later, symptoms such as skin rash, fever and aches in the joints and muscles usher in the secondary stage. These symptoms also eventually disappear (in about 4-12 weeks) and the disease ceases to be infectious, but a blood test for the presences of the bacteria generally remains positive. During this “symptomless” period called the latent stage, which may last up to 20 years, the bacteria may invade body organs. When signs of organ degeneration appear, the disease is said to be in tertiary stage. If the organs of the nervous system become involved, the tertiary stage is called neurosyphilis. Neurosyphilis may take different forms, depending on the tissue involved. Cerebellar damage is manifested by uncoordinated movements in activities such as writing, As the motor areas become extensively damaged, victims may be unable to control urine and bowel movements. Eventually, they may become bedridden, unable even to feed themselves.
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Damage to the cerebral cortex produces memory loss and personality changes that range from irritability to hallucinations, AIDS and other disorders that compromise the immune system may speed the progression of heurosyphilis, possibly by impairing macrophages and antibody production. Syphilis can be treated with antibiotics (penicillin) during the primary, secondary and latent periods. Certain forms of neurosyphilis may also be successfully treated, but the prognosis for others is very poor. (d) Genital Herpes Type II herpes simplex virus (HSV-2) causes genital infections, such as painful genital blisters on the prepuce, glans penis and penile shaft in males and on the vulva or sometimes high up in the vagina in females. The blisters disappear and reappear in most patients, but the virus itself remains in the body. A related virus, type I herpes simplex virus (HSV-1), causes cold sores on the mouth and lips. Infected persons typically experience recurrences of symptoms several times a year. Treatment of the symptoms involves pain killer medication, saline compresses, sexual abstinence for the duration of the eruption, and use of oral drug called acyclovir (Zovirax). This drug interferes with viral DNA replication but not with host cell DNA replication. Acyclovir speeds the healing and sometimes reduces the pain of initial genital herpes infections. (e) Chancroid Chancroid is a sexually transmitted disease caused by he short gram –ve bacillus Haemophilus ducrei. The incubation period is 3-5 days. The initial lesion at the site of inoculation breaks down to from a painful, soft ulcer with a necrotic base. With lymph node involvement, fever and chills may occur. Women may have no external signs of infections. Chancroid must be differentiated from other genital ulcers. The chancre of syphilis, by contrast, is clean and painless, with a hard base. A single dose of either azithromycin or ceftriaxone given intramuscularly is effective. (f) Genital Warts Warts are infectious diseases caused by viruses. Sexual transmission of genital warts is common and is caused by the Human Papilloma Virus (HPV). Patients with a history of genital warts may be at increased risk for cervical, vaginal, anal, vulval and penile cancers. Treatment consists of cryotherapy with liquid nitrogen, electrocautery, excision, laser surgery and topical application of podophyllin in tincture of benzoin. Apha-interferon is also used to treat genital warts. PAP smear is done as screening test for cervical cancer. (g) AIDS : Acquired Immuno Deficiency Syndrome AIDS is caused by Human Immunodeficiency Virus (HIV). HIV can get transmitted through blood and also by sexual contract between males and females through vaginal, oral or anal intercourse. Male homosexuals transmit HIV to their partner by anal or oral intercourse. (h) HIV enters body cells by CD4 receptor-mediated endocytosis involving T4 cells. With time, the number of T4 cells, mainly helper T cells, declines due to death of infected cells. The result is progressive collapse of the immune system and the person becomes susceptible to opportunistic infections (invasion of normally harmless micro-organisms that now proliferate widely because of the defective immune system).
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(i) The first and still most commonly used drug to treat AIDS is AZT (azidothymidine) or Retrovir. Other drugs are DDI (Dedeoxyinosine), DDC (dedeoxycytidine) and D4T (stavudine) or Zerit. (j) Trichomoniasis The microorganism Trichomonas vaginalis, a flagellated protozoan, causes trichomoniasis, an inflammation of the mucous membrane of the vagina in female and urethra in males where it is a common inhabitant. If the normal acidity of the vagina is disrupted, the protozoan may overgrow the normal microbial population and cause trichomoniasis. Symptoms include a yellow vaginal discharge with a particularly offensive odour and severe vaginal itch. Men can have it without overt symptoms but can nevertheless transmit it to women. Sexual partners must be treated simultaneously. The drug of choice is metronidazole.
05. Infertility Infertility (L. in-not, fertilis-fruitful) is the failure to conceive even after 1-2 years of regular unprotected sex. The term is not synonymous with sterility; which means complete inability to produce offspring. Infertility can best be defined as relative sterility. It is of to types – primary and secondary. Primary infertility is the infertility found in patients who have never conceived. Secondary infertility is found in patients who have previously conceived. Infertility can be caused by defects found in males or females.
Infertility in Males Semen of a fertile male is 2.5 to 5 ml per ejaculation with a sperm count of over 200-300 million, mostly motile, having proper fructose content and fluidity which is deposited high in the vagina. Any defect in sperm count, sperm structure, sperm motility of seminal fluid leads to infertlity. Low sperm count is called oligospermia while near absence of sperms is known as azoospermia. Low sperm motility is called asthenozoospermia while defective sperm morphology is termed as teratozoospermia. Various causes of infertility in males include : (a) Cryptorchidism or failure of testes to descend into scrotum. (b) Absence or blockage of vasa deferentia. (c) Hyperthermia or higher scrotal temperature due to varicocele (varicose veins), hydrocele or filariasis, tight undergarment, thermal undergarment or working in hot environment cause oligospermia or depressed spermatogenesis (d) Infections like mumps after puberty (orchitis or inflammation of testes), bronchiectasis (chronic dilation of bronchioles), infection of seminal vesicles or prostate result in oligospermia. Infections of Chlamydia trachomatis and T. mycoplasma (=Ureoplasma) also cause oligospermia. (e) Alcoholism inhibits spermatogenesis.
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(f) (g) (h) (i)
Klinefelter’s syndrome. Gonadtropin deficiency. Cytotoxic drugs, radiations, antidepressant and anticonvulsant drugs supress spermatogenesis. Low fructose content, high prostaglandin content, high viscosity and low volume of ejaculate lead to male infertility.
Infertility in Females A fertile woman is the one who regularly ovulates once every cycle, passes the egg down the reproductive tract which develops conditions for smooth passage of sperms and implantation of fertilised egg. The various causes of infertility in females are as follows : (a) Anovulation (nonovulation) and oligoovulation (deficient ovulation) are caused by deficient functioning of hypothalamo-pituitary complex or secondarily by thyroid and adrenal dysfunction. (b) Inadequate growth and functioning of corpus luteum resulting in reduced progesterone secretion and deficient secretory changes in endometrium. It is called luteal phase defect it inhibits implantation. (c) The ovum is not liberated but remains trapped inside the follicle due to hyperprolactinaemia. (d) Fallopian tube may fail to pick up ovum, have impaired motility, loss of cilia and blocked lumen. The defects may be caused by infection or endometriosis. (e) Noncanalisation of uterus. (f) Defective uterine endometrium due to reduced or excessive secretory activity. (g) Congenital malformation of uterus. (h) Fibroid uterus. (i) Defects in cervix like congenital elongation, occlusion of cervix by a polyp, cervicitis, scanty or excessive cervical mucus and presence of antisperm antibodies. (j) Defective vaginal growth.
06. Assisted Reproductive Technologies (Art) More than two decades ago, in an experimental procedure called in vitro fertilization (IVF), doctors joined a woman’s egg and a man’s sperm in a glass dish in a laboratory. For the first time, fertilization happened outside a woman’s body. Nine months later, the first test-tube baby was born. Today, Assisted Reproductive Technology (ART) refers not only to IVF but also to several variations tailored to patient’s unique conditions. These procedures are usually paired with more conventional therapies, such as fertility drugs, to increase success rates. Almost one out of every three cycles of ART results in the birth of a baby. But ART procedures are invasive and expensive. Though no long-term health effects have been linked to children born using ART procedures, most doctor recommend reserving ART as a last resort for having a baby. Here’s a rundown of the main ART techniques : (a) In vitro fertilization (IVF) :This is one of the most commonly used procedures. Eggs are combined with partner’s sperm in a dish in a laboratory. Once fertilization has occurred, the resulting embryos develop for 3 to 5 days before being placed in uterus.
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(b) Intracytoplasmic sperm injection (ICSI) : One of he partner’s sperms is placed inside the egg with a microscopic needle, rather than many sperms positioned close to the outside of the egg as in IVF, in a dish in a lab. Once fertilization occurs, the resulting embryo is placed in uterus. (c) Gamete intrafallopian transfer (GIFT) : Transfer of an ovum collected from a donor into the fallopian tube (GIFT) of another female who cannot produce one, but can provide suitable environment for fertilisation and further development. (d) Zygote intrafallopian transfer (ZIFT) : In test-tube baby programme, ova from the wife/donor (female) and sperms from the husband/donor (male) are collected and are induced to form zygote under simulated conditions in the laboratory. The zygote or early embryo (with upto 8 blastomeres) could then be transferred into the fallopian tube (ZIFT) and embryos with more than 8 blastomers into the uterus (IUT-Intra-Uterine Transfer) to complete its further development. (e) Artificial Insemination (AI) : If the infertility of male is either due to inability of male partner to achieve an erection of penis to inseminate the female or due to very low sperm count in the semen, it is corrected by AI. In AI, the semen collected either from the husband or a healthy donor is artificially introduced either into the vagina or into the uterus (IUI – intra uterine insemination) of the female. (f) Donor egg or embryo : If one is unable to conceive using her own eggs, an egg donated by another woman is mixed with partner’s sperms and the resulting embryo is implanted in the uterus. This procedure can also be done with a donated embryo or sperm. (g) Surrogacy or use of a gestational carrier : Another woman carries embryo or a donor embryo to term.
Some Biological Terms: IVF-ET GIFT ZIFT IUI POST SUZI ICSI TESE MESA
: : : : : : : : :
In vitro fertilization and embryo transfer Gamete intra-fallopian transfer Zygote intra-fallopian transfer Intra-uterine insemination Peritoneal oocyte and sperm transfer Subzonal insemination Intra-cytoplasmic sperm injection Testicular sperm extraction Microsurgical epididymal sperm aspiration
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CLASS NOTES FOR CBSE – 04. Reproduction Health
CBSE Pattern Exercise (1) 1. What are MTPs ? Under what conditions MTPs are legally permitted? 2. Describe the technique which is used for sex determination in foetus? 3. Describe the three manners in which fertilization of human ovum by sperm can be prevented? 4. Suggest some methods to assist infertile couples to have children? 5. Give another name for sexually transmitted diseases. Name two sexually transmitted diseases which are curable and two diseases which are not curable. 6. Differentiate between Vasectomy and Tubectomy. 7. Name the techniques which are employed in following cases : (a) Transfer of an ovum collected from a donor into the fallopian tube of another female who cannot produce ova but can provide suitable environment for fertilization and development. (b) Embryo is formed in laboratory in which sperm is directly injected into ovum. Semen collected either from husband or a healthy donor is artificially introduced either into vagina or uterus. 8. What is the significance of progesterone-estrogen combination as a contraceptive measure? 9. Copper ions-releasing IUDs are more efficient than non-medicated methods. Why? 10.What are the suggestive reasons for population explosion?
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