Alcohol can trigger either a migraine or a cluster headache. There are 3 main triggers in alcohol: Dark alcoholic beverages, such as red wine, sherry, brandy, scotch, bourbon, and beer, contain tyramine. Tyramine is an amino acid that occurs naturally in your body and is also found in many foods.
Sometimes a twin pregnancy just happens. In other cases, specific factors are at play. For example, a twin pregnancy is more likely as you get older because hormonal changes can cause more than one egg to be released at a time. Use of assisted reproductive technologies â such as in vitro fertilization â also boosts the odds of twins or other multiples.
Fraternal twins â the most common kind â occur when two separate eggs are fertilized by two different sperm. Each twin has his or her own placenta and amniotic sac. The twins can be two girls, two boys, or a boy and a girl. Genetically, they're no more alike than any other siblings. Identical twins occur when a single fertilized egg splits and develops into two fetuses. Identical twins might share a placenta, but each baby usually has a separate amniotic sac. Genetically, the two babies are identical. They'll be the same sex and share physical traits and characteristics.