Fertility rates start decreasing after the age of 30.
So when we reach the age of 35 even an external fertilisation like 'Vitro fertilisation' is difficult. The risk of miscarriage or a fertilisation outside the uterus(ectopic pregnancy) is great. There is no way to transplant the foetus in ectopic pregnancy into the uterus and therefore abortion is inevitable.
Women after the age of 30 undergo some hormonal changes and these changes normally affect not only the muscles of the uterus but also the foetus within it. After the age of 35, these hormonal changes bring about complication during delivery.
The hormonal change is directly linked to the muscular contraction of the uterus which after 35 gets sagged. Therefore during delivery labour pain is not regular and the contraction and expansion of uterus muscle are not systematic which hampers normal delivery resulting in forceps delivery or a caesarian delivery.
Having a successful conception does not do away the foetus related risk. The chromosomal problem stands to be the greatest complication. The baby develops down syndrome a condition in which the baby develops an extra copy of the 21st chromosome which delays physical and mental development and at times the baby is born with both mental and physical disabilities.
Women after thirty-five are likely to develop diabetes and high blood pressure during pregnancy. Gestational diabetes causes the baby to grow larger than the average weight and may result in injuries during delivery. An increase in blood pressure may lead to miscarriage and the baby may also develop hypertension.
Hence pregnancy before the age of 30 is always safe, but if ever you conceive after 35 it's better to take prenatal vitamins like vitamin B with folic acid that is good for the baby's nerves and be in constant touch with your doctor to avoid complications during pregnancy and after delivery.