MPharm - Pregnancy, Menopause & Contraception Notes

What happens during the Follicular phase?

Estrogen stimulates the proliferation of the endometrial stroma, preparing the uterine lining for potential implantation.

What happens during the Luteal phase?

Progesterone induces secretory, glandular, and decidualization changes in the endometrium, making it receptive to a fertilized egg.

What is Histiotrophic nutrition?

It is essential during pre-implantation, providing nutrients to the early embryo before it implants in the uterine wall.

What is the Implantation window?

Days 20-24 of the menstrual cycle when the endometrium is most receptive to implantation, stimulated by estrogen's release of glandular secretions.

What does the Syncytiotrophoblast do?

Secretes human Chorionic Gonadotrophin (hCG) approximately 1 week post-fertilization to support the corpus luteum and maintain progesterone production.

What happens to hCG levels and what does it indicate?

hCG levels fall from week 8 but remain detectable throughout pregnancy; their presence in urine or blood indicates a biochemical pregnancy.

What is Progesterone?

An absolute requirement throughout pregnancy; produced from cholesterol by the syncytiotrophoblast, with the placenta taking over from the corpus luteum around week 6 after ovariectomy to maintain the pregnancy.

What does Mifepristone (RU486) do?

It acts as an anti-progesterone, blocking progesterone receptors and preventing the hormone from exerting its effects.

What is Estriol?

The predominant form of estrogen during pregnancy, synthesized through a cooperative effort between the placenta and the fetus.

How is Estrogen produced?

A cooperative effort by the placenta and the fetus, involving progesterone converted to Androgen in the fetal adrenal glands, then Androgen converted to Estrogen in the placenta.

What does Human Placental Lactogen (hPL) do?

Acts as an anti-insulin agent, causing decreased insulin sensitivity and increased maternal blood glucose to provide for the fetus; increases lipolysis, leading to the release of free fatty acids (FFA).

What happens with Prolactin (PRL)?

Levels rise linearly during pregnancy; estrogen stimulates prolactin release by lactotroph cells of the anterior pituitary, with small amounts also produced by the decidua (amniotic fluid).

What happens during Stage 1 of Parturition?

Contractions begin, leading to shortening/effacement and dilation of the cervix.

What happens during Stage 2 of Parturition?

Full dilation of the cervix, resulting in the delivery of the baby.

What happens during Stage 3 of Parturition?

Delivery of the placenta.

What mediates Cervical Ripening/Softening?

Mediated by Prostaglandin E (PGE), relaxin, and Nitric Oxide (NO), preparing the cervix for labor and delivery.

How is Myometrial Contractility controlled during pregnancy?

Kept quiescent by progesterone suppressing contractility via decreasing oxytocin receptor expression to prevent premature labor.

What is the Ferguson Reflex?

Neuroendocrine reflex where pressure/stretching of the cervix by the baby’s head stimulates further release of oxytocin, creating a positive feedback loop to intensify contractions.

What is the Fetal role in timing of Parturition?

Maturation of the fetal hypothalamic-pituitary-adrenal (HPA) axis, with fetal glucocorticoids and corticotrophin-releasing hormone (CRH) increasing at term, leading to increased estrogen and prostaglandin, initiating labor.

What is the Anatomy of the Breast?

Composed of 15-20 lobes of glandular tissue with fibrous/adipose tissue between the lobes; lobes contain lobules of alveoli, blood vessels, and lactiferous ducts.

What are Alveoli?

Consist of epithelial cells (synthesize milk), myoepithelial cells, and a basement membrane.

What happens during Breast Development?

At birth, mostly lactiferous ducts are present with few alveoli; during puberty, estrogen stimulates lactiferous duct sprouting and branching, alveoli start to develop, and fat and connective tissue is deposited.

What happens during Pregnancy and Lactation?

Up to the 4th month of pregnancy, estrogen and progesterone further develop the alveoli and dilate the lumens; prolactin (PRL) rises throughout pregnancy but is inhibited from causing milk secretion until after parturition.

What is the Milk Ejection/Let-Down Reflex?

Stimulation of the nipple leads to oxytocin release, causing contraction of myoepithelium and ejection of milk.

What is the Life of a Human Egg?

Primordial germ cell migration to the genital ridge during early development; primary oogonium arrested at prophase I in utero; ovulation occurs at puberty; secondary oocyte arrested at metaphase II.

What are the Oogonia and Oocytes Count?

• PGC migration starts with ~ 170 cells.
• Reaches 600,000 around 8/40 (likely referring to gestational weeks).
• Peaks at 7,000,000 around 20/40 (likely referring to gestational weeks).
• Decreases to 2,000,000 at birth.
• Further decreases to 400,000 at puberty.
• A small number are ovulated during a woman's reproductive years.

What is Perimenopause/Climacteric?

Period of reproductive change that precedes menopause, lasting up to ten years; symptoms include Oligomenorrhea, Mood changes, Loss of libido, and Hot flushes. Oestrogen falls, FSH and LH rise

What is Menopause?

• 12 months of amenorrhea (over 50 years old).
• 24 months of amenorrhea (under 50 years old).

What are the Consequences of Estrogen Withdrawal?

Loss of anti-PTH activity, leading to bone catabolism and osteoporosis; change in blood lipid ratios, increasing the risk of coronary thrombosis; Reduction in vaginal lubrication, leading to dyspareunia; Behavioral changes which may be endocrine or psychological.

What is Hormone Replacement Therapy (HRT)?

Usually a combination of synthetic progesterone and estrogen; Estrogen-only HRT is only suitable for women who have had a hysterectomy; Unopposed estrogen can lead to endometrial hyperplasia and endometrial cancer.

How do Hormonal Contraceptives function?

Mimic hormonal levels during pregnancy, leading to feedback inhibition by progesterone (and estrogen) on the hypothalamic-pituitary-gonadal (HPG) axis; constant exposure to progesterone suppresses ovulation.

What is the Emergency Contraceptive Pill (Morning After Pill)?

Contains higher levels of hormones than normal contraceptive pills and can prevent or delay ovulation, and alter the environment of the uterus, reducing the likelihood of implantation.

How do Barrier Methods work?

Prevent pregnancy by physically blocking the egg and sperm from meeting; have higher failure rates than hormonal methods due to design and human error.

What is Cu-IUD (Copper IUD)?

Placed in the uterus, lasts 5-12 years (LARC), and is extremely effective without using hormones (>99%); it releases leukocytes and prostaglandins, creating a hostile environment for sperm and embryos.

What is LNG-IUD (Levonorgestrel-releasing IUD)?

Lasts 5 years (LARC), continuously releases small amounts of progestin (levonorgestrel), leading to atrophy of the endometrium, with most women becoming anovulatory after the first year.

What is Female Sterilisation = Tubal Ligation?

Major surgical procedure where uterine tubes are cut/tied/cauterized/clipped, preventing eggs from reaching sperm.

What is Male Sterilisation = Vasectomy?

Ligation of the Vas Deferens tube, usually an outpatient procedure with a faster recovery than tubal ligation.

What are Natural Methods of Contraception?

Include coitus interruptus/withdrawal, rhythm method (menstrual cycle), Fertility Awareness method, natural family spacing (lactational amenorrhoea), and abstinence.

What is UKMEC (UK Medical Eligibility Criteria for Contraceptive Use)?

Provides guidance to providers of contraception on who can use