H1N1 During Implantation

If you conceived seven days before your illness, your baby-to-be would have been close to implantation, which occurs seven to ten days after conception. At this stage, the baby’s cells are rapidly dividing and beginning to separate into body and placenta, but no other organs would be formed.

As you correctly note, increased temperature can cause harm to developing babies, especially during early pregnancy. However, maternal temperature below 102.2F for less than 50 hours has not been shown to cause harm to a growing baby.

Before organ development, it is most likely that a short episode of high fever (eg more that 50 hours above 102.2) would lead to loss of the pregnancy, rather than an abnormality in the baby. Fever later on can cause damage to the developing nervous system, which is why prolonged exercise and soaking in hot tubs is not recommended in early pregnancy. These risks are probably lower later on, but it is still best to avoid any activity that increases your body  temperature in pregnancy.

For more about development, see the chapter on the amazing placenta in my book Gentle Birth, Gentle Mothering,. www.sarahjbuckley.com