No... it's connected to fertility and the way humans are. You can raise the fertility level up to a certain point.. But after that... no. It should be a Log or Exponential scale of Fertility. (once out of eggs? no more eggs, can't exactly put the egg carton back in the fridge expecting more..)   Periods of starvation and manutrition and elite physical training like Ultra Marathoners can cause miscarriages obviously.. but the other one is it can stop normal menstration cycles completely