Gird your loins for we are amid a reproductive revolution, or so I am informed in Birth, episode six of the Netflix documentary series Human: The World Within. Over the past 50 years, scientific research has significantly advanced our understanding of reproduction, fundamentally transformed the field of fertility, and provided society with new routes to parenthood. We are introduced to the impact of this research via a group of refreshingly diverse birthing parents, with babies cute enough to stir some semblance of emotion even in my cold, non-paternal heart.
Consequences of decisions made during pregnancy have surprising longevity, as highlighted alongside the birthing journey of Jack, a 31 year-old professional dancer based in Singapore. In an emotional moment while Jack listens to her baby's heartbeat (ironically matching the rhythm of 'can't you hear me knocking' by the Rolling Stones), we are reminded of the impact of parental diet and exercise on fetal development. More interestingly, however, the episode considers the epigenetic implications of the environment. Medical practitioner Dr Robynne Chutkan notes how behaviours such as smoking can affect several subsequent generations by directly modifying genes within fetal gametes. Despite not referencing specific studies, current work is examining whether epigenetics is responsible for rising infertility rates, estimated to affect one in seven couples.
Infertility is reviewed through the story of Jenny, who is striving to raise awareness of IVF and reduce stigma around infertility within the black community. Before eventually getting pregnant, Jenny had 15 fibroids (non-cancerous tumours) removed from her uterus which, astonishingly, can occur in up to 80 percent of uteruses. Reminiscent of the message of Invisible Women by Caroline Criado-Perez, more research is clearly needed on the female reproductive system as we are informed that 25 percent of pregnancies end in miscarriage and a third of all infertility cases remain unexplained. Fortunately, Jenny achieved a successful birth through the modern miracle of IVF and is pregnant with her second child.
As a childless millennial, it remained surprisingly interesting to learn about the biological complexity of vaginal birth and why newborns look like they've just finished Tough Mudder. When babies emerge from the birth canal, they're coated in beneficial bacteria, which boosts their immune system, and a waxy cream termed vernix caseosa. This substance protects the fetus' skin from amniotic fluid during gestation but also minimises heat loss following birth, akin to a biological sweater. Although I remain apprehensive, squeezing of the baby's brain as it passes through the cervix in a vaginal delivery is also believed to influence long-term expression of immune system and tumour-suppressor genes, indicating the sensitivity of the developmental process.
The episode concludes with Mac, a professional doula who provides non-medical support to birthing parents during pregnancy and childbirth. As a transgender man, he was inspired by the queer families he worked with to carry his own child, mirroring the journey of Freddy McConnell – the subject of the documentary Seahorse (see BioNews 1016). To prevent issues with body dysmorphia, Mac elected for a caesarean section with his daughter Rowan, avoiding a long physiological labour which I learned can last for well over 36 hours! For reference, you could watch the entirety of the Harry Potter and Lord of the Rings sagas during that time, although I doubt you could pay attention to the plot.
Following birth, Rowan was fed breastmilk donated by local breastfeeding parents (due to Mac having previously had top surgery) with the narrator explaining the scientific justification behind the adage 'breast is best'. The third most common ingredient of breast milk, human milk oligosaccharides (HMOs), is undigestible by babies and instead feeds gut bacteria, contributing to a healthy digestive system. This is just one example of how, like university freshers on a night out, newborns are completely reliant on those around them for survival.
Despite craving more scientific detail, I found the episode provided a heart-warming overview of birth in the 21st century, concluding that although our identities may differ, we are unified by the fact that all of us were born.