What Is Minipuberty And How Does It Affect Fertility?

People are generally familiar with puberty. As noted in Hormone Research in Paediatrics, it is the time in early adolescence when boys and girls go through the hormonal surges which will turn their bodies into young men and women who are capable of having children. However, the term "minipuberty" may be less familiar to many of us.

Another peak in hormones occurs in babies during their first few months of life, which is called "minipuberty," according to a 2016 article published in the American Academy of Pediatrics. During minipuberty, testosterone production is increased in male babies, and estradiol and testosterone production is increased in girls (albeit at a much lower concentration than in boys).

No one knows exactly why it happens, but it may serve three purposes. For starters, it plays a role in the development of the genitals. Plus it seems to affect the baby boy's body composition thus determining his body mass index (BMI), his body weight as well as how quickly he grows during the first six months of his life. Lastly, it has an effect on language development, with testosterone affecting language organization in the brain and estradiol affecting sound production by the baby's larynx, as per Hormone Research in Paediatrics.

Minipuberty's influence on fertility

A 2018 review of the medical literature surrounding minipuberty published in the journal Frontiers in Endocrinology clarifies what we currently know about the influence of minipuberty on fertility. The increase in sex hormones that occurs during minipuberty allows the genitals to mature. In boys, the penis and testicles grow and the cells of the gonads grow in number. In girls, estradiol triggers the growth of breast tissue. These changes are temporary and may not be readily apparent to the observer. Minipuberty is important because the development of sex organs creates the basis for future fertility, as per Frontiers in Endocrinology. 

Research indicates that supplying hormones that mimic minipuberty could help repair undescended testicles and underdeveloped penises as well as induce normal activation of Sertoli and Leydig cells in boys, according to a report by Healio. It is thought that this may help improve fertility in males with these conditions.