Reproductive Health & Endocrine System — Hormones, Family Planning & Population Policy

Overview

The endocrine system is a network of glands that produce hormones — chemical messengers regulating growth, metabolism, reproduction, and homeostasis. Understanding hormones and their disorders is essential for UPSC Prelims, while reproductive health policies (PCPNDT Act, NPP 2000, Surrogacy Regulation Act 2021) are important for both Prelims and Mains (GS-II: Social Issues). India's achievement of a Total Fertility Rate of 2.0 (NFHS-5, 2019–21) — below the replacement level of 2.1 — marks a significant demographic milestone.

Exam Strategy: For Prelims, memorise the hormone-gland-function-disorder table — questions often test specific hormones (e.g., "Which gland secretes insulin?", "What causes goitre?"). For Mains, focus on India's population policy, TFR trends, and legislative measures like the PCPNDT Act and Surrogacy Regulation Act.

The Endocrine System — Endocrine vs Exocrine Glands

Feature	Endocrine Glands	Exocrine Glands
Secretion	Hormones (chemical messengers)	Enzymes, sweat, saliva, mucus
Delivery	Directly into the bloodstream (ductless)	Through ducts to a specific site
Target	Distant organs/tissues via blood	Local area (skin, digestive tract)
Examples	Pituitary, thyroid, adrenal, pancreas (endocrine part)	Salivary glands, sweat glands, liver, pancreas (exocrine part)

Key Fact: The pancreas is both endocrine and exocrine — its Islets of Langerhans secrete hormones (insulin, glucagon) directly into the blood, while its acinar cells secrete digestive enzymes into the duodenum via the pancreatic duct.

Major Endocrine Glands and Their Hormones

Hypothalamus

Located in the brain, below the thalamus
Acts as the link between the nervous system and the endocrine system
Produces releasing and inhibiting hormones that control the pituitary gland
Regulates body temperature, hunger, thirst, sleep, and circadian rhythms

Pituitary Gland — The "Master Gland"

Located at the base of the brain (pea-sized). Called the "master gland" because its hormones regulate many other endocrine glands. However, the hypothalamus controls the pituitary, so it is sometimes called the "master of the master gland."

Anterior Pituitary Hormones:

Hormone	Full Name	Target/Function
GH (HGH)	Growth Hormone (Human Growth Hormone)	Stimulates growth of bones, muscles, and tissues
TSH	Thyroid-Stimulating Hormone	Stimulates the thyroid gland to produce T3 and T4
ACTH	Adrenocorticotropic Hormone	Stimulates the adrenal cortex to produce cortisol
FSH	Follicle-Stimulating Hormone	Stimulates ovarian follicle development (females) and sperm production (males)
LH	Luteinising Hormone	Triggers ovulation (females) and testosterone production (males)
Prolactin	Prolactin	Stimulates milk production in mammary glands after childbirth

Posterior Pituitary Hormones:

Hormone	Function
ADH (Vasopressin)	Promotes water reabsorption in kidneys; reduces urine volume; raises blood pressure
Oxytocin	Stimulates uterine contractions during childbirth; promotes milk ejection during breastfeeding; often called the "love hormone"

Thyroid Gland

Located in the front of the neck (butterfly-shaped). Requires iodine for hormone synthesis.

Hormone	Function
T3 (Triiodothyronine)	Regulates metabolic rate, heart rate, body temperature
T4 (Thyroxine)	Same as T3 (converted to T3 in tissues); more abundant but less active
Calcitonin	Lowers blood calcium levels (deposits calcium in bones)

Parathyroid Glands

Four tiny glands on the posterior surface of the thyroid.

Hormone	Function
PTH (Parathyroid Hormone)	Raises blood calcium levels (releases calcium from bones, increases calcium absorption in intestine and kidneys)

Prelims Tip: Calcitonin (thyroid) and PTH (parathyroid) have opposite effects on blood calcium. Calcitonin lowers calcium; PTH raises calcium. Together, they maintain calcium homeostasis.

Adrenal Glands

Two triangular glands sitting on top of each kidney. Each has two parts: the outer cortex and the inner medulla.

Adrenal Cortex:

Hormone	Function
Cortisol	Stress response — increases blood sugar, suppresses immune system, aids fat/protein/carbohydrate metabolism
Aldosterone	Regulates sodium and potassium balance; controls blood pressure
Androgens	Small amounts of male sex hormones (in both sexes)

Adrenal Medulla:

Hormone	Function
Adrenaline (Epinephrine)	"Fight or flight" response — increases heart rate, blood pressure, blood sugar, dilates airways
Noradrenaline (Norepinephrine)	Works with adrenaline; constricts blood vessels, raises blood pressure

Key Fact: Adrenaline is called the "emergency hormone" or "fight-or-flight hormone." When you are frightened or excited, the adrenal medulla releases adrenaline, preparing the body for rapid action — heart beats faster, blood sugar rises, pupils dilate, and blood flows to muscles.

Pancreas (Endocrine Function)

The Islets of Langerhans contain two key cell types:

Cell Type	Hormone	Function
Beta cells	Insulin	Lowers blood glucose — promotes glucose uptake by cells, glycogen storage in liver
Alpha cells	Glucagon	Raises blood glucose — stimulates glycogen breakdown in liver, releases glucose into blood

Gonads (Sex Glands)

Gland	Hormone	Function
Testes (male)	Testosterone	Development of male secondary sexual characteristics, sperm production
Ovaries (female)	Oestrogen	Development of female secondary sexual characteristics, regulation of menstrual cycle
Ovaries (female)	Progesterone	Maintains pregnancy, prepares uterus lining for implantation

Other Hormone-Producing Organs

Organ	Hormone	Function
Pineal Gland	Melatonin	Regulates sleep-wake cycle (circadian rhythm)
Thymus	Thymosin	Maturation of T-lymphocytes (immune cells); active in childhood, shrinks with age
Kidneys	Erythropoietin (EPO)	Stimulates red blood cell production in bone marrow
Stomach	Gastrin	Stimulates secretion of gastric acid
Heart	ANP (Atrial Natriuretic Peptide)	Lowers blood pressure by promoting sodium and water excretion

Comprehensive Hormone Table — Gland, Hormone, Function, Disorder

Gland	Hormone	Key Function	Hypo (Deficiency) Disorder	Hyper (Excess) Disorder
Pituitary (Anterior)	Growth Hormone	Growth of bones and tissues	Dwarfism (in children)	Gigantism (children) / Acromegaly (adults)
Pituitary (Posterior)	ADH	Water reabsorption in kidneys	Diabetes insipidus (excessive urination)	SIADH (water retention)
Thyroid	T3/T4	Metabolic rate regulation	Hypothyroidism — cretinism (children), myxoedema (adults)	Hyperthyroidism — Graves' disease
Thyroid	Calcitonin	Lowers blood calcium	Rarely significant clinically	Rarely significant clinically
Parathyroid	PTH	Raises blood calcium	Hypocalcaemia, tetany	Hypercalcaemia, kidney stones
Adrenal Cortex	Cortisol	Stress response, metabolism	Addison's disease (fatigue, low BP, darkened skin)	Cushing's syndrome (moon face, obesity, high BP)
Adrenal Cortex	Aldosterone	Na+/K+ balance, blood pressure	Low blood pressure, dehydration	Conn's syndrome (high BP, low potassium)
Adrenal Medulla	Adrenaline	Fight-or-flight response	—	Pheochromocytoma (high BP, anxiety)
Pancreas	Insulin	Lowers blood glucose	Diabetes mellitus	Hypoglycaemia (low blood sugar)
Pancreas	Glucagon	Raises blood glucose	Hypoglycaemia	Hyperglycaemia
Testes	Testosterone	Male characteristics, sperm	Hypogonadism	Early puberty, aggression
Ovaries	Oestrogen/Progesterone	Female characteristics, pregnancy	Menstrual irregularities, osteoporosis	PCOD/PCOS, endometriosis
Pineal	Melatonin	Sleep-wake cycle	Insomnia, jet lag	Seasonal depression (SAD)

Major Endocrine Disorders

Diabetes Mellitus

Feature	Type 1 Diabetes	Type 2 Diabetes
Cause	Autoimmune destruction of beta cells in pancreas	Insulin resistance — cells do not respond properly to insulin
Onset	Usually childhood/young adulthood	Usually adulthood (increasingly in youth due to obesity)
Insulin	Little or no insulin produced	Insulin produced but ineffective
Treatment	Insulin injections (lifelong)	Diet, exercise, oral medication, sometimes insulin
Prevalence in India	~5% of diabetic population	~95% of diabetic population

Thyroid Disorders

Disorder	Cause	Key Symptoms
Goitre	Iodine deficiency — thyroid enlarges trying to produce more T3/T4	Swollen neck, fatigue, weight gain
Cretinism	Congenital hypothyroidism (in infants/children)	Stunted growth, intellectual disability
Myxoedema	Hypothyroidism in adults	Weight gain, fatigue, cold intolerance, puffy face
Graves' Disease	Autoimmune hyperthyroidism	Weight loss, bulging eyes (exophthalmos), rapid heartbeat

Prelims Tip: Goitre is caused by iodine deficiency — the thyroid gland swells as it tries to produce adequate hormones. This is why iodised salt is mandatory in India. The National Iodine Deficiency Disorders Control Programme (NIDDCP) promotes universal salt iodisation.

Other Important Disorders

Disorder	Gland/Hormone	Description
Dwarfism	Pituitary — GH deficiency in childhood	Abnormally short stature, proportionate body
Gigantism	Pituitary — excess GH in childhood	Abnormally tall stature
Acromegaly	Pituitary — excess GH in adulthood	Enlarged hands, feet, jaw (bones cannot grow longer, only thicker)
Addison's Disease	Adrenal cortex — cortisol deficiency	Fatigue, weight loss, low BP, darkened skin
Cushing's Syndrome	Adrenal cortex — excess cortisol	Moon face, central obesity, high BP, thin skin
PCOD/PCOS	Ovaries — hormonal imbalance	Irregular periods, excess androgens, ovarian cysts, infertility
Diabetes Insipidus	Pituitary — ADH deficiency	Excessive urination, extreme thirst (NOT related to blood sugar)

Reproductive Health

Reproductive and Child Health (RCH) Programme

India's RCH Programme was launched in 1997 under the National Rural Health Mission (now National Health Mission). It focuses on:

Maternal and child health
Immunisation
Family planning
Adolescent health
Implementation of the PCPNDT Act

PCPNDT Act — Ban on Sex Determination

The Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act, 1994 (amended 2003) prohibits:

Sex determination of the foetus
Pre-conception sex selection
Advertisement of sex determination facilities

Feature	Details
Year enacted	1994 (amended 2003)
Purpose	Prevent female foeticide and sex-selective abortions
Key provision	Any medical professional revealing the sex of the foetus faces imprisonment (up to 5 years) and fine
Regulatory body	Central Supervisory Board + State/UT Appropriate Authorities
Context	India's adverse child sex ratio — 927 girls per 1000 boys (Census 2011) prompted stricter enforcement

Family Planning Methods

Category	Method	How It Works
Natural Methods	Rhythm method (calendar-based)	Abstinence during fertile period (ovulation days)
Natural Methods	Lactational amenorrhoea (LAM)	Breastfeeding suppresses ovulation for ~6 months post-delivery
Barrier Methods	Male condom	Physical barrier preventing sperm from reaching egg
Barrier Methods	Female condom (Femidom)	Lines the vagina, preventing sperm entry
Barrier Methods	Diaphragm/Cervical cap	Covers the cervix, blocking sperm
Hormonal Methods	Oral contraceptive pills (OCPs)	Synthetic hormones (oestrogen + progesterone) prevent ovulation
Hormonal Methods	Injectable (DMPA — Antara)	Depot medroxyprogesterone acetate injection every 3 months
Hormonal Methods	Emergency contraception (i-pill)	High-dose levonorgestrel taken within 72 hours of unprotected intercourse
IUDs	Copper-T (CuT)	Copper ions create hostile environment for sperm; prevents implantation
IUDs	Hormonal IUD (Mirena)	Releases levonorgestrel locally; thickens cervical mucus
Surgical Methods	Vasectomy (male)	Cutting and sealing the vas deferens — blocks sperm release
Surgical Methods	Tubectomy (female)	Cutting and sealing the fallopian tubes — blocks egg from reaching uterus

Key Fact: India introduced injectable contraceptive DMPA (brand name Antara) in the public health system in 2017. It is administered once every three months and is available free at government health facilities.

India's Population Policy and TFR Trends

National Population Policy 2000 (NPP 2000)

Feature	Details
Objective	Achieve replacement-level fertility (TFR of 2.1) by 2010 and stable population by 2045
Key targets	Reduce IMR to <30/1000, MMR to <100/100,000, achieve universal immunisation
Approach	Voluntary, not coercive — incentives for adoption of small family norm

Total Fertility Rate (TFR) Trends

Survey	TFR
NFHS-1 (1992–93)	3.4
NFHS-2 (1998–99)	2.9
NFHS-3 (2005–06)	2.7
NFHS-4 (2015–16)	2.2
NFHS-5 (2019–21)	2.0

Milestone: As per NFHS-5 (2019–21), India's TFR has declined to 2.0 — below the replacement level of 2.1. This means India's population will eventually stabilise and then decline (with a time lag due to population momentum). The achievement came about a decade after the NPP 2000 target year of 2010.

Replacement-level fertility (2.1) means each woman has, on average, enough children to "replace" herself and her partner in the population, accounting for child mortality.

Assisted Reproduction

In Vitro Fertilisation (IVF)

Egg is fertilised with sperm in a laboratory dish ("test-tube baby")
The embryo is then transferred to the uterus
First IVF baby — Louise Brown (UK, 1978)
First IVF baby in India — Durga (born Kanupriya Agarwal, 1978) — just 67 days after Louise Brown

Surrogacy Regulation Act, 2021

Feature	Details
Year enacted	2021 (effective 25 January 2022)
Key provision	Bans commercial surrogacy in India; only altruistic surrogacy permitted
Who can avail	Indian married couples (wife 25–50 years, husband 26–55 years) who have been married for 5 years; certain medical conditions required
Surrogate	Must be a close relative of the intending couple; married with at least one child; aged 25–35; can be a surrogate only once
Regulatory body	National Surrogacy Board + State Surrogacy Boards
Amendments	2023 amendment allowed single women (widows/divorcees) and couples with medical conditions to use donor gametes

Exam Tip: The Surrogacy (Regulation) Act, 2021 and the Assisted Reproductive Technology (Regulation) Act, 2021 were passed together. The ART Act regulates ART clinics, banks, and procedures (IVF, ICSI, etc.). Both Acts aim to protect the rights of women and children involved in surrogacy and ART procedures.

Frequently Asked Questions (Prelims Pattern)

Question	Answer
Which gland is called the "master gland"?	Pituitary gland (controlled by hypothalamus)
Which hormone is called the "fight-or-flight" hormone?	Adrenaline (epinephrine)
What causes goitre?	Iodine deficiency (thyroid swells trying to produce T3/T4)
What is the difference between Type 1 and Type 2 diabetes?	Type 1: no insulin production (autoimmune); Type 2: insulin resistance
What does the PCPNDT Act prohibit?	Pre-natal sex determination and sex-selective abortion
What is India's TFR as per NFHS-5?	2.0 (below replacement level of 2.1)
What is the replacement-level fertility rate?	TFR of 2.1
What is IVF?	In vitro fertilisation — egg fertilised with sperm in a laboratory dish
Which Act regulates surrogacy in India?	Surrogacy (Regulation) Act, 2021
Which hormone regulates sleep?	Melatonin (pineal gland)
Which hormone lowers blood sugar?	Insulin (beta cells of pancreas)
What is Cushing's syndrome?	Excess cortisol — moon face, obesity, high BP

Recent Developments (2024–2026)

India's Diabetes Burden — 101 Million Cases (2024 IDF Data)

The International Diabetes Federation (IDF) Diabetes Atlas data cited widely in 2024 confirmed India has approximately 101 million people living with diabetes — second only to China — with an additional 136 million with prediabetes. This reflects a crisis in pancreatic beta-cell function (Type 2 diabetes: insulin resistance) and lifestyle factors. The NP-NCD programme's HbA1c screening expansion to Community Health Centres in 2024 aims to detect and manage diabetes at the primary care level.

UPSC angle: India's diabetes burden (101 million) is the most cited endocrine system public health fact — directly connects pancreatic hormone physiology to India's NCD crisis.

Endocrine Disruptors — ICMR Research and Health Policy (2024)

ICMR-NIN's 2024 Dietary Guidelines specifically addressed the growing evidence on endocrine-disrupting chemicals (EDCs) — BPA in plastics, phthalates in personal care products, and certain pesticides — as significant environmental health threats. EDCs interfere with thyroid hormones, reproductive hormones, and growth hormone signalling. India's FSSAI began reviewing food contact material regulations in 2024 to reduce BPA exposure, particularly for infant feeding products.

UPSC angle: Endocrine disruptors are an emerging science-environment-health interface topic — relevant for GS3 questions connecting chemical pollution to endocrine system disorders and reproductive health.

Key Terms for Quick Revision

Term	Meaning
Endocrine Gland	Ductless gland that secretes hormones directly into the bloodstream
Exocrine Gland	Gland that secretes substances through ducts to a specific site
Hormone	Chemical messenger produced by endocrine glands, regulating body functions
Insulin	Hormone from pancreatic beta cells that lowers blood glucose
Glucagon	Hormone from pancreatic alpha cells that raises blood glucose
Adrenaline	Emergency hormone from adrenal medulla triggering fight-or-flight response
Thyroxine (T4)	Thyroid hormone regulating metabolic rate
TFR	Total Fertility Rate — average number of children born to a woman in her lifetime
Replacement-Level Fertility	TFR of 2.1 — population replaces itself without growth
PCPNDT Act	Pre-Conception and Pre-Natal Diagnostic Techniques Act, 1994 — bans sex determination
IVF	In Vitro Fertilisation — "test-tube baby" technique
Altruistic Surrogacy	Surrogacy without commercial compensation (only medical expenses covered)
NFHS	National Family Health Survey — India's comprehensive demographic health survey

Sources: Cleveland Clinic (Endocrine System); Johns Hopkins Medicine; PIB (pib.gov.in — India TFR, Deep Ocean Mission); PRS India (NFHS-5 Vital Stats); Wikipedia (Endocrine system, PCPNDT Act, Surrogacy in India); MOHFW (rch.mohfw.gov.in — RCH Programme); India Code (Surrogacy Regulation Act 2021).