Puberty is the process of reproductive and sexual development and the maturation which changes a child into an adult.

Menopause is defined as the cessation of menstruation for a period of 12 months. Premature menopause is defined as cessation of menstruation before the age of 40.

Hormones that increase during pregnancy and their roles:

1. Human Chorionic Gonadotropin (hCG): Peaks between the eighth to tenth weeks of gestation and supports the corpus luteum to maintain progesterone production.
2. Progesterone: Initially produced by the corpus luteum and later by the placenta, it rises steadily throughout pregnancy, suppressing the maternal immune response to fetal antigens and preparing the endometrium for implantation.
3. Estrogen: Produced by the placenta from fetal and maternal precursors, estrogen levels increase to promote uterine growth and blood flow.
4. Human Placental Lactogen (hPL): Rises significantly during pregnancy, influencing maternal metabolism by increasing insulin resistance and promoting lipolysis.
5. Relaxin: Increases early in pregnancy to relax the uterine muscles, inhibit contractions, and prepare the cervix and pelvis for childbirth.
6. Prolactin: Levels increase to prepare the breasts for lactation.
7. Corticotropin-Releasing Hormone (CRH): Increases towards the end of pregnancy and is involved in the timing of labor.
8. Adrenocorticotropic Hormone (ACTH): Levels increase, contributing to elevated cortisol levels during pregnancy.
9. Total Thyroxine (T4): Levels increase due to elevated thyroid-binding globulin (TBG) production stimulated by increased estrogen levels, meeting the increased metabolic demands of pregnancy.
10. Parathyroid Hormone (PTH): Levels increase to regulate calcium metabolism, ensuring adequate calcium for fetal bone development.
11. Cortisol: Levels increase due to higher production by the adrenal glands and increased binding to cortisol-binding globulin (CBG), supporting glucose metabolism, managing stress, and aiding fetal development, particularly lung maturation.

During pregnancy, some hormones either remain stable or do not increase significantly. These include:

1. Follicle-Stimulating Hormone (FSH): Levels decrease due to the negative feedback from high levels of estrogen and progesterone.
2. Luteinizing Hormone (LH): Levels also decrease due to negative feedback from elevated estrogen and progesterone.
3. Growth Hormone (GH): Although a variant of growth hormone (hGH-V) is produced by the placenta and increases, the maternal pituitary GH levels may not significantly increase.
4. Melatonin: Generally remains stable during pregnancy, though some studies suggest there may be slight fluctuations.
5. Insulin: While insulin resistance increases due to hPL and other factors, the actual levels of insulin may not increase proportionally; instead, pancreatic beta-cell function adapts to meet the increased demand.

Liver cirrhosis is known to lead to decreased levels of SHBG. Other causes of high SHBG are:
Oestrogens e.g. oral contraceptives
Pregnancy
Hyperthyroidism
Liver cirrhosis
Anorexia nervosa
Drugs e.g. anticonvulsants

Uterine blood flow increases 40-fold to approximately 700 mL/min at term, with 80 per cent of the blood distributed to the intervillous spaces of the placentae, and 20 per cent to the uterine myometrium.

The case presented points to a diagnosis of an autoimmune thyroiditis leading to hypothyroidism. The most common form of autoimmune hypothyroidism, Hashimoto’s, often presents with a goitre, positive for antibody tests against thyroid components i.e. anti-TPO and anti-thyroglobulin. Graves disease and toxic diffuse goitre are more likely to cause hyperthyroidism. While De-Quervain’s and endemic goitre may cause hypothyroidism, they don’t result in positive antibody tests.

The metabolic adaptations of pregnancy are orchestrated by hormones produced by the placenta and maternal pituitary gland, which undergo dramatic changes during gestation. After involution of ovarian sex steroid production by wk 6, placental oestrogen and progesterone production increases exponentially to term. Concurrently, there are progressive increases in prolactin (PRL), produced by the maternal pituitary gland and decidua, and human chorionic somatomammotropin (CSH, also called human placental lactogen), which has structural similarities to GH and PRL.

The placenta produces Estriol from 16-OH DHEAS. Estriol is the major oestrogen (oestrogen) of pregnancy and the placenta is the primary site of production. Pregnenolone is synthesised by the placenta from cholesterol and this is converted to dehydroepiandrosterone (DHEA) in the fetal adrenal gland

Oxytocin is the primary stimulus for uterine involution following childbirth.

After the release of the oocyte, the theca and the granulosa cells form the corpus luteum which undergoes extensive vascularization for continued steroidogenesis. Progesterone is secreted by the luteal cells and is synthesized from cholesterol.