Countdown to life : the extraordinary making of you. 1/3, The first 8 weeks.

This three-part series explores how our lives are shaped day-by-day by genetic developments in the womb. Part One follows the first 8 weeks of foetal development. Presenter Michael Mosley introduces a group of quadruplets and explains the genetic processes behind conception. He explores how what a mother eats around the time of conception can affect the development of her baby in the womb. He visits Gambia, where a study has been conducted into babies’ development, depending on whether they were conceived in the wet or dry seasons. Melanie Gaydos talks about living with the genetic condition Ectodermal Dysplasia. Gaydor and her doctor discuss the results of a genetic test that explains the cause of her condition – an incredibly rare variation of the TP63 gene. Mosley moves on to explain how growth genes function. He introduces a young girl who overproduces the growth hormone IGF2. She undergoes a check-up of her vital organs to check for tumours in her kidneys. Mosley explains the role of cilia in the shaping of our internal organs. He introduces basketball player Randy Foye, who has the rare condition, Situs Inversus. Mosley explains the development of the heart, whilst a couple undergo an ultrasound at 5 weeks of pregnancy. Another couple are introduced whose baby undergoes a life-saving operation to repair her abnormally narrow aorta. Mosley explains how hands are formed, and introduces a family in Brazil who almost all have 6 fingers on each hand. Finally, Mosley explains the development of the vestibular system.