Class 12 Biology Notes Chapter 4 (Reproductive Health) – Biology Book

Okay, let's focus on the key concepts from Chapter 4: Reproductive Health, as per the NCERT Class 12 Biology textbook, relevant for government exam preparation.

Chapter 4: Reproductive Health

1. Reproductive Health: Problems and Strategies

• Definition (WHO): Reproductive health means total well-being in all aspects of reproduction, i.e., physical, emotional, behavioural, and social.
• India's Initiatives: India was among the first countries to initiate national-level action plans and programmes ('Family Planning' initiated in 1951).
• RCH Programmes: Reproductive and Child Health Care (RCH) programmes are currently operational.
  • Goals: Creating awareness among people about various reproduction-related aspects and providing facilities and support for building up a reproductively healthy society.
  • Components:
    • Introduction of sex education in schools.
    • Proper information about reproductive organs, adolescence and related changes, safe and hygienic sexual practices, STIs (Sexually Transmitted Infections) including AIDS.
    • Information for fertile couples and marriageable age groups about available birth control options, care of pregnant mothers, post-natal care of mother and child, importance of breastfeeding, equal opportunities for male and female child.
    • Awareness of problems due to uncontrolled population growth, social evils like sex-abuse and sex-related crimes.
    • Successful implementation requires strong infrastructural facilities, professional expertise, and material support.
    • Statutory ban on amniocentesis for sex determination to prevent female foeticides.
    • Research on various reproduction-related areas is encouraged (e.g., Saheli - oral contraceptive for females developed by CDRI, Lucknow).

2. Population Stabilisation and Birth Control

• Population Explosion: Rapid increase in population size over a relatively short period.

  • Reasons: Decline in death rate (maternal mortality rate - MMR & infant mortality rate - IMR), increase in the number of people in the reproducible age.
  • Consequences: Scarcity of basic requirements (food, shelter, clothing).
  • Measures to Control: Motivating smaller families using contraceptive methods, raising marriageable age (female - 18 years, male - 21 years), incentives to couples with small families.

• Contraceptive Methods (Birth Control):

  • Ideal Contraceptive: User-friendly, easily available, effective, reversible with no or least side-effects, should not interfere with sexual drive/desire/act.
  • Categories:
    • a) Natural/Traditional Methods: Work on the principle of avoiding chances of ovum and sperm meeting.
      • i) Periodic Abstinence: Avoiding coitus from day 10 to 17 of the menstrual cycle (fertile period). High failure rate.
      • ii) Withdrawal/Coitus Interruptus: Male withdraws penis from the vagina just before ejaculation. High failure rate.
      • iii) Lactational Amenorrhea: Absence of menstruation during intense lactation following parturition. Ovulation does not occur. Effective up to a maximum of six months. No side effects, but high chances of failure.
    • b) Barrier Methods: Prevent physical meeting of ovum and sperms.
      • i) Condoms: Barriers made of thin rubber/latex sheath. Cover penis (male) or vagina/cervix (female). Prevent deposition of semen into the vagina. Disposable. Protects user from STIs and AIDS. Popular brand for males: Nirodh.
      • ii) Diaphragms, Cervical Caps, Vaults: Barriers made of rubber, inserted into the female reproductive tract to cover the cervix during coitus. Reusable. Spermicidal creams/jellies/foams often used along with these to increase contraceptive efficiency.
    • c) Intra Uterine Devices (IUDs): Inserted by doctors/expert nurses into the uterus through the vagina.
      • i) Non-medicated IUDs: e.g., Lippes loop. Increase phagocytosis of sperms within the uterus.
      • ii) Copper releasing IUDs: e.g., CuT, Cu7, Multiload 375. Copper ions suppress sperm motility and fertilising capacity.
      • iii) Hormone releasing IUDs: e.g., Progestasert, LNG-20. Make the uterus unsuitable for implantation and the cervix hostile to sperms.
      • Note: IUDs are ideal contraceptives for females who want to delay pregnancy/space children. One of the most widely accepted methods in India.
    • d) Oral Contraceptives:
      • i) Pills: Contain either progestogens alone or progestogen-estrogen combinations. Taken daily for 21 days starting within the first five days of the menstrual cycle, followed by a 7-day gap. Inhibit ovulation and implantation; alter the quality of cervical mucus to prevent/retard sperm entry. Very effective, lesser side effects.
      • ii) Saheli: 'Once a week' pill developed by CDRI, Lucknow. Non-steroidal preparation. High contraceptive value with very few side effects.
    • e) Injectables and Implants: Progestogens alone or in combination with estrogen used as injections or implants under the skin. Mode of action similar to pills, but effective for much longer periods.
    • f) Emergency Contraceptives: Administration of progestogens or progestogen-estrogen combinations or IUDs within 72 hours of coitus. Used to avoid possible pregnancy due to rape or casual unprotected intercourse.
    • g) Surgical Methods (Sterilisation): Terminal method to prevent any more pregnancies. Very effective, but reversibility is poor. Blocks gamete transport.
      • i) Vasectomy (Male): Small part of the vas deferens is removed or tied up through a small incision on the scrotum.
      • ii) Tubectomy (Female): Small part of the fallopian tube is removed or tied up through a small incision in the abdomen or through the vagina.

• Side Effects of Contraceptives: Possible side effects like nausea, abdominal pain, breakthrough bleeding, irregular menstrual bleeding, or even breast cancer (though not significant) should be considered. Consult a qualified medical professional for selection. Contraceptives are not for regular requirement but to prevent pregnancy.

3. Medical Termination of Pregnancy (MTP)

• Definition: Intentional or voluntary termination of pregnancy before full term. Also called induced abortion.
• Legality: Legalised in India in 1971 (MTP Act) with strict conditions to avoid misuse (e.g., female foeticide).
• Indications: To get rid of unwanted pregnancies (due to unprotected intercourse, contraceptive failure, rapes) or in cases where pregnancy continuation could be harmful/fatal to mother, foetus, or both.
• Safety: Relatively safe during the first trimester (up to 12 weeks). Second-trimester abortions are much riskier.
• Misuse: Often misused for illegal female foeticide.
• Need for Counselling: Need for effective counselling on avoiding unprotected coitus and the risk factors involved in illegal abortions.

4. Sexually Transmitted Infections (STIs)

• Definition: Infections or diseases transmitted through sexual intercourse. Also called Venereal Diseases (VD) or Reproductive Tract Infections (RTI).
• Common Examples: Gonorrhoea, Syphilis, Genital Herpes, Chlamydiasis, Genital Warts, Trichomoniasis, Hepatitis-B, HIV leading to AIDS.
• Mode of Transmission:
  • Sexual contact with infected persons.
  • Sharing injection needles, surgical instruments.
  • Transfusion of blood.
  • From infected mother to foetus (Hepatitis B, HIV).
• Exceptions: Hepatitis-B and HIV can also be transmitted by non-sexual means mentioned above. Genital herpes and HIV infections are currently incurable; others are treatable if detected early.
• Symptoms: Often minor or absent in early stages, especially in females. Include itching, fluid discharge, slight pain, swellings, etc., in the genital region. Absence/less significant symptoms increase chances of transmission.
• Complications if Untreated: Pelvic Inflammatory Diseases (PID), abortions, stillbirths, ectopic pregnancies, infertility, cancer of the reproductive tract.
• Prevention:
  • Avoid sex with unknown/multiple partners.
  • Always use condoms during coitus.
  • Consult a qualified doctor for early detection and treatment if symptoms appear or in case of doubt.
• Age Group: High incidence in the 15-24 years age group.

5. Infertility

• Definition: Inability to conceive or produce children even after 2 years of unprotected sexual cohabitation.
• Causes: Can be physical, congenital, diseases, drugs, immunological, or even psychological. Problem can lie with the male, female, or both partners.
• Treatment: Specialised health care units (infertility clinics) can help diagnose and treat causes.
• Assisted Reproductive Technologies (ART): Options when corrections/treatments are not possible.
  • a) In Vitro Fertilisation (IVF) - Test Tube Baby Programme: Ova from wife/donor female and sperms from husband/donor male are collected and induced to form a zygote under simulated conditions in the laboratory.
    • Embryo Transfer (ET):
      • ZIFT (Zygote Intra Fallopian Transfer): Zygote or early embryo (up to 8 blastomeres) transferred into the fallopian tube.
      • IUT (Intra Uterine Transfer): Embryo with more than 8 blastomeres transferred into the uterus.
  • b) Gamete Intra Fallopian Transfer (GIFT): Transfer of an ovum collected from a donor into the fallopian tube of another female who cannot produce one but can provide a suitable environment for fertilisation and further development.
  • c) Intracytoplasmic Sperm Injection (ICSI): Specialised procedure where a sperm is directly injected into the ovum in the laboratory. Embryo formed is transferred via ET (ZIFT/IUT).
  • d) Artificial Insemination (AI): Semen collected from the husband or a healthy donor is artificially introduced into the vagina or uterus (Intra-Uterine Insemination - IUI) of the female. Used in cases of male infertility (inability to inseminate or low sperm counts).
• Considerations: ART requires high precision handling by specialised professionals and expensive instrumentation. Availability is limited. Emotional, religious, and social factors are also deterrents.
• Adoption: Often the best option for couples looking for parenthood, especially in India where many orphaned/destitute children need homes.

Key Acronyms to Remember:

• WHO: World Health Organization
• RCH: Reproductive and Child Health Care
• MMR: Maternal Mortality Rate
• IMR: Infant Mortality Rate
• IUD: Intra Uterine Device
• MTP: Medical Termination of Pregnancy
• STI: Sexually Transmitted Infection
• VD: Venereal Disease
• RTI: Reproductive Tract Infection
• AIDS: Acquired Immuno Deficiency Syndrome
• HIV: Human Immunodeficiency Virus
• PID: Pelvic Inflammatory Disease
• ART: Assisted Reproductive Technology
• IVF: In Vitro Fertilisation
• ET: Embryo Transfer
• ZIFT: Zygote Intra Fallopian Transfer
• IUT: Intra Uterine Transfer
• GIFT: Gamete Intra Fallopian Transfer
• ICSI: Intracytoplasmic Sperm Injection
• AI: Artificial Insemination
• IUI: Intra-Uterine Insemination
• CDRI: Central Drug Research Institute

Focus on the definitions, examples, mechanisms of action (especially for contraceptives and ART), full forms of acronyms, and preventive measures for STIs, as these are frequently asked areas in government exams. Good luck!