Identical twins originate from one particular egg that's been fertilized by one sperm. For unknown reasons, the fertilized egg splits into 2 or more embryos during the first stage of development. Some identical twins share the same placenta. However, they generally grow within separate amniotic sacs inside the uterus. In rare cases, identical twins share one amniotic sac (monoamniotic). Alarms have been raised, however, regarding dangers related to hormone replacement therapy (HRT). These risks have been found in connection with what is known as commercial HRT. Possible side effects include thrombosis or blood clots, lowered glucose tolerance, migraine headaches, vision problems, acne, depression and bloating. Women have been known to experience breast tenderness, too. The issue raises an essential but underexposed component that plays a crucial role in everyone's health and quality lifestyle ' hormone balance. The researchers' findings coincide in what experts already know about hormones: Keeping them in harmony is critical to maintaining your physical health, together with your mental and emotional well-being. Ankylosing spondylitis - a long-term inflammation that affects mainly the spine's bones, muscles and ligaments, resulting in stiff and joint fusion. Other problems may include swelling of tendons, eyes and joints.