According to the general belief, morning sickness is taken as a favorable sign and is associated with blessing in disguise.
Studies have postulated that women who have nausea during pregnancy were less likely to miscarry. It supports a prior study by the National Institutes of Health that found that women who had morning sickness in the first four months of pregnancy were 30% less likely to miscarry.
There is no particular reason that would answer the cause. However, it has been assumed that hormone produced by healthy placental tissue might lead to nausea or vomiting while other theory postulates that the sickness may help women avoid foods that could harm a developing fetus.
However, many women have normal pregnancies with no morning sickness, and many miscarry without getting sick. Thus, morning sickness is related with a lower rate of miscarriage, though it is not necessarily a sign of a healthy pregnancy.
