What are the risks of breastfeeding during pregnancy (for the mom, baby and the embryo/fetus)? Is it prohibit?

Breastfeeding. Breastfeeding is not prohibited during pregnancy. It may require more nutrients to be consumed though to cover the expenditure for breastfeeding and growing fetus. Otherwise, it will not harm anyone.
Yes. While it is safe to breast feed you might consider monitoring the cues of your present baby to see if you can wean before the new baby comes along.Continued nurturing time with alternate feeds & increasing table feeds may help this. Be mindful that the newborn will need the feeds more.Your OB may want you to stop if this seems to trigger contractions that would start you into early labor.
Talk to a MD with... Experience working with pregnant and breastfeeding mothers. For some women with high risk pregnancies, breastfeeding is not recommended during the pregnancy. Some women do tandem breastfeed. However it is key to discuss this with your ob/gyn. Get clarification from your doctor please.

Related Questions

What are the risks of being on seroxat during pregnancy and/or breastfeeding? And are there other substitutes that can be safer for the fetus?

Seroxat ; Pregnancy. There has been some concern about potential heart defects when babies are born of mothers using paroxetine (seroxat) http://tinyurl.com/lhkeo4w -- but other studies have not shown ill effect: http://tinyurl.Com/ka2jdt7 zoloft (sertraline) and Celexa have not been implicated and could be safer in pregnancy. Zoloft (sertraline) is the oldest ; most studied -- relatively safe in breastfeeding too. http://tinyurl.com/5t44qah. Read more...