Fetuses resulting from the same zygote share 100% of their genetic material and hence are called identical. Identical twins are always the same sex. Terminology
Terms used for the number of offspring in a multiple birth, where a number higher than three ends with the suffix -uplet:

two offspring – twins
three offspring – triplets
four offspring – quadruplets
five offspring – quintuplets
six offspring – sextuplets
seven offspring – septuplets
eight offspring – octuplets
nine offspring – nonuplets
ten offspring – decupletsTerms used for multiple births or the genetic relationships of their offspring are based on the zygosity of the pregnancy:

Monozygotic – multiple (typically two) fetuses produced by the splitting of a single zygote
Polyzygotic – multiple fetuses produced by two or more zygotes:
Dizygotic – multiple (typically two) fetuses produced by two zygotes
Trizygotic – three or more fetuses produced by three zygotes
Sesquizygotic – an egg which is fertilized by 2 sperms, which produce 2 fetusesMultiple pregnancies are also classified by how the fetuses are surrounded by one or more placentas (chorionicity) and amniotic sacs (amnionicity). Human multiple births
In humans, the average length of pregnancy (two weeks fewer than gestation) is 38 weeks with a single fetus. This average decreases for each additional fetus: to thirty-six weeks for twin births, thirty-two weeks for triplets, and thirty weeks for quadruplets. With the decreasing gestation time, the risks from immaturity at birth and subsequent viability increase with the size of the sibling group. Only as of the twentieth century have more than four all survived infancy. Recent history has also seen increasing numbers of multiple births.
The drug Brindley injected into his penis was a non-specific vasodilator, an alpha-blocking agent, and the mechanism of action was clearly corporal smooth muscle relaxation. The effect that Brindley discovered established the fundamentals for the later development of specific, safe, and orally effective drug therapies.The current first-line treatment for ED, the oral PDE5 inhibitor, was introduced by Pfizer in 1999. Anthropology
Anthropological research presents ED not as a disorder but, as a normal, and sometimes even welcome sign of healthy aging. Wentzells study of 250 Mexican men in their 50s and 60s found that “most simply did not see decreasing erectile function as a biological pathology”. The men interviewed described the decrease in erectile function “as an aid for aging in socially appropriate ways”. A common theme amongst the interviewees showed that respectable older men shifted their focus toward the domestic sphere into a “second stage of life”. The Mexican men of this generation often pursued sex outside of marriage; decreasing erectile function acted as an aid to overcoming infidelity thus helping to attain the ideal “second stage” of life. A 56-year-old about to retire from the public health service said he would now "dedicate myself to my wife, the house, gardening, caring for the grandchildren—the Mexican classic". Wentzell found that treating ED as a pathology was antithetical to the social view these men held of themselves, and their purpose at this stage of their lives. In the 20th and 21st centuries, anthropologists investigated how common treatments for ED are built upon assumptions of institutionalized social norms.