Ten things we learned about pregnancy from the BBC documentary series The 9 Months That Made You

The 9 Months That Made You is an informative and entertaining documentary series. It traces how we grow from a single cell and form into a human baby. This series is presented by Dr Michael Mosley and is produced and directed by Nicola Cook (Horizon). Through a series of excellent animations and case studies we can learn more about the amazing processes that are involved in creating the gift of life. Here are ten lessons we learned from this thought-provoking and insightful program, airing Thursdays on BBC Knowledge.

1. The first eight weeks are vital. This period follows conception and the formation of a single cell into the growth of an embryo and then a foetus with arms, legs, an up-right spine and rudimentary brain. The cells are initially identical and they will eventually split into some 400,000 different types.

2. What a mother eats at conception can affect the longevity of her offspring. Some studies in Gambia have found that young adults who were conceived as babies during the dry season were seven times more likely to die at a young age than their counterparts conceived during the wet season. This has been attributed to the differences in the mother’s diets during the different seasons.

3. One in 10,000 people have developed organs on the wrong side of their body and this happened whilst they were in-utero. Situs inversus occurs in people who have their heart on their right side and their liver on the left.

4. When an embryo is five weeks old we can already see its heart beating on an ultrasound. This is despite the fact that at this point the heart is only one centimetre long.

5. A protein called sonic hedgehog is responsible for making the digits on your hands grow in-utero. People with increased amounts of this protein can develop extra fingers. This is not the only problem an embryo or foetus can develop involving its hands, there are people with Immigration Delay Disease which means that they have no finger prints.

6. In utero we already start to favour one hand over the other. Over 90% of humans are right-handed.

7. There are parts of the Dominican Republic where 1 in 90 genetic males are born with no penis. They are called guevedoces which means “Penis at 12” because the surge of testosterone at the on-set of puberty means these males eventually do grow a penis.

8. One explanation for transgender individuals could be attributed to the fact that the sex of the foetus’ brain and its body occurs at different times during the gestation period. For example, if the testosterone in a male foetus fails to reach its brain this can result in a mis-match where the genetic male person identifies as a female.

9. The first sense we develop in the womb is hearing. At 28 weeks, the foetus can hear the outside world. One study had pregnant mothers read their foetus a nursery rhyme every day for multiple weeks. The results found that the baby’s heart rate dropped when they heard this familiar text and that no change occurred when an unfamiliar text was read. The reduced heart rate also occurred when a different individual read the same nursery rhyme to the foetus.

10. There is a theory that the propensity to develop Type II diabetes could be influenced by the mother’s diet during pregnancy. The theory states that if the mother’s diet is low in fat, sugar and calories and then the off-spring grows up consuming a diet high in these things they will develop Type II diabetes. One study showed two genetically-identical rats where one was very fat and large and the other was a normal weight where the key difference between the two was that the mother of the latter had consumed a diet high in folic acid and vitamin B12 during the pregnancy.

The 9 Months That Made airs Thursdays at 8.30pm on BBC Knowledge (Foxtel).