In May 2021, the Cissé nonuplets were born in Morocco to Halima Cissé, a 25-year-old woman from Mali. As of May 2022, one year since their births, all nine are still living and reportedly in good health. The list of multiple births covers notable examples. Causes and frequency
The frequency of N multiple births from natural pregnancies has been given as approximately 1:89N−1 (Hellins law) and as about 1:80N−1. This gives:

1:89 (= 1.1%) or 1:80 (= 1.25%) for twins
1:892 (= 1:7921, about 0.013%) or 1:802 (= 1:6400) for triplets
1:893 (= approx. 0.000142%, less than 1:700,000) or 1:803 for quadrupletsNorth American dizygotic twinning occurs about once in 83 conceptions, and triplets about once in 8000 conceptions. US figures for 2010 were:
Twins, 132,562, 3.31%
Triplets, 5,503, 0.14%
Quadruplets, 313, 0.0078%
Quintuplets and more, 37, 0.00092%Human multiple births can occur either naturally (the woman ovulates multiple eggs or the fertilized egg splits into two) or as the result of infertility treatments such as in vitro fertilization (several embryos are often transferred to compensate for lower quality) or fertility drugs (which can cause multiple eggs to mature in one ovulatory cycle). For reasons that are not yet known, the older a woman is, the more likely she is to have a multiple birth naturally. It is theorized that this is due to the higher level of follicle-stimulating hormone that older women sometimes have as their ovaries respond more slowly to FSH stimulation.The number of multiple births has increased over the last decade.
Side effects
Sodium and water retention
Swelling due to fluid retention (edema)
High blood pressure (hypertension)
Headache
Low blood potassium level (hypokalemia)
Muscle weakness
Fatigue
Increased susceptibility to infection
Impaired wound healing
Increased sweating
Increased hair growth (hirsutism)
Thinning of skin and stretch marks
Disturbances of the gut such as indigestion (dyspepsia), distention of the abdomen and ulceration (peptic ulcer)
Decreased bone density and increased risk of fractures of the bones
Difficulty in sleeping (insomnia)
Depression
Weight gain
Raised blood sugar level
Changes to the menstrual cycle
Partial loss of vision due to opacity in the lens of the eye (cataracts)
Raised pressure in the eye (glaucoma)
Increased pressure in the skull (intracranial pressure)

Pharmacology
Fludrocortisone is a corticosteroid and acts as a powerful mineralocorticoid, along with some additional but comparatively very weak glucocorticoid activity. Relative to cortisol, it is said to have 10 times the glucocorticoid potency but 250 to 800 times the mineralocorticoid potency. Fludrocortisone acetate is a prodrug of fludrocortisone, which is the active form of the drug.Plasma renin, sodium, and potassium are checked through blood tests to verify that the correct dosage is reached. Chemistry
Fludrocortisone, also known as 9α-fluorocortisol (9α-fluorohydrocortisone) or as 9α-fluoro-11β,17α,21-trihydroxypregn-4-ene-3,20-dione, is a synthetic pregnane steroid and a halogenated derivative of cortisol (11β,17α,21-trihydroxypregn-4-ene-3,20-dione). Specifically, it is a modification of cortisol with a fluorine atom substituted in place of one hydrogen atom at the C9α position. Fluorine is a good bioisostere for hydrogen because it is similar in size, with the major difference being in its electronegativity. The acetate form of fludrocortisone, fludrocortisone acetate, is the C21 acetate ester of fludrocortisone, and is hydrolyzed into fludrocortisone in the body.