Pregnancy
Caffeine readily crosses the placenta and can accumulate in the fetus because the fetus does not have the liver enzymes to detoxify it. It is now known that  caffeine  increases the risk of miscarriages (and possibly birth defects) and inhibits fetal growth. Caffeine also may make it harder to get pregnant.

Fibrocystic Breast Disease
The effect of caffeine on fibrocystic breast disease is still controversial among the professional community. Some physicians advise women with FBD to limit their caffeine intake. But several studies---including a report on more than 3.300 women issued by the National Institutes of Health--- have found no relationship between fibrocystic disease and caffeine consumption. Nor is there any evidence that giving up caffeine by itself eases the pain experienced by some women.

Lactation
Very few studies have been reported on the effects of caffeine on breast milk. It has been observed that irritability and insomnia are present in some infants when their mothers have consumed large mounts of caffeine, i.e. 5-8 cups coffee.

Recommendation
The advice of many authorities is to limit
caffeine ingestion to approximately 300/mg/day during pregnancy and lactation.

Caffeine and Cholesterol
Most evidence suggests that coffee prepared using a disposable paper filter removes nearly all of the cafestrol and kahweol. These two compounds are found in the oil
          of the coffee  bean and have been found to raise levels of LDL cholesterol----also known as bad cholesterol, the artery clogging kind.

Although  more research is needed, there does appear to be an association between caffeine intake and hip fractures.

A principle cause of fractures is reduced bone mass. While the most important determinant of bone mass is the genetic one, there are many other contributing factors. While good nutrition and physical activity promote bone density, alcohol use, cigarette smoking and caffeine intake are associated with detrimental effects.