At age 40, your risk for any genetic problem is one in 65. My mother was two months pregnant and had a miscarriage. It is an egg which gets fertilized but never develops an embryo that can be seen. Sometimes the placenta can continue to grow and produce pregnancy hormones that still make one feel pregnant but the baby's development is stopped extremely early. The shot given to prevent any type of maternal reaction to the baby's blood type is given between 26 and 28 weeks during the pregnancy.
Pre eclampsia can affect the development when the placenta gets severely scarred.
When this happens, blood flow to the baby can be severely reduced or even stopped causing severe growth restriction or even death. One way is by increasing vitamins to include extra iron and folic acid. They also need special ultrasounds to monitor their growth throughout the pregnancy. This is particularly true with identical twins sharing one placenta. Frequent small meals can help women who would like to assure a good weight gain.