What is normal? A study of normal breastfeeding dyads during the first sixty hours of life

The human microbiota begins developing at birth and undergoes continual change as we age. Infancy marks a critical period of microbial sensitivity, offering a “window of opportunity” during which beneficial microbes help mature the immune system. By age three, children typically develop a more stable and diverse microbial community. Newborns acquire microbes from their immediate environment; vaginal delivery favors maternal vaginal microbes, while cesarean births favor microbes from the skin...

The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...

The sense of taste begins developing before birth and is shaped by biological predispositions and early experience. During pregnancy, flavors from foods consumed by the mother can enter the amniotic fluid, exposing the fetus to different flavors. These prenatal experiences may contribute to food preferences after birth.Prenatal and Breastfeeding InfluencesAfter birth, flavors from a mother’s diet can also pass into breast milk. Repeated exposure to these flavors during breastfeeding may make...

Communication in infancy begins with crying, a reflexive and adaptive behavior that signals needs such as hunger, discomfort, or anger. Variations in pitch, pattern, and intensity help caregivers interpret these states, making crying an important survival mechanism during the neonatal period.Emergence of VocalizationsBy about six weeks, infants begin cooing, producing vowel-like sounds, squeals, and gurgles that often indicate contentment. Between six and ten months, cooing develops into...

Behavioral imprinting is observed in some newborn animals and occurs when they develop strong and specific attachments to another animal (usually a parent) following brief, early-life exposures. Offspring imprint onto parents within a brief period after birth or hatching; this time window is called the critical period. Once imprinting occurs, the bond established between the parents and their offspring is usually long-lasting.