Why can't I get pregnant?
When trying for a baby, it can be extremely discouraging when it just isn’t happening for you. In general, infertility is defined by the failure to achieve pregnancy withing 12 months of having regular unprotected sex. According to the WHO, 15% of reproductive-aged couples are affected by infertility worldwide. 
WHAT CAUSES INFERTILITY?
Infertility may be caused by an issue with either you or your partner – since it can affect both men and women – or a combination of factors that may result in failure to conceive.
For pregnancy to be a success, all steps during ovulation must happen correctly and in order. Sometimes, infertility issues may be present in individuals from birth, and sometimes they present themselves later in life. For a quarter of couples, a cause cannot be found. 
The main symptom of infertility in women is not getting pregnant. You probably don’t need to see a doctor about fertility issues unless you’ve been trying to get pregnant regularly for at least one year.
One of the main causes of infertility is age. When a woman reaches 35, fertility will rapidly decline due to the lower number and quality of eggs. Other common causes include:
Uterine or cervical abnormalities
Fallopian tube damage
Primary ovarian insufficiency
Cancer and its treatment 
HOW CAN I PREVENT FERTILITY ISSUES?
There are a number of things you can do in order to increase your chances of becoming pregnant. One thing you do have control over are certain lifestyle choices that have been proven to interfere with pregnancy. Here are a few things you can do:
Avoid alcohol and drugs
Avoid being overweight or underweight
WHAT TREATMENT OPTIONS ARE THERE FOR INFERTILITY?
Fortunately, there are many treatment options available for people that are suffering from infertility. These vary quite a bit between males and females.
For women, there are 3 main types of fertility treatments. These include medicines, surgical procedures, and assisted conception such as intrauterine insemination (IUI) and vitro fertilization (IVF).
Medicines are usually prescribed to women that aren’t ovulating regularly. These drugs aim to stimulate ovulation and can enable a woman to optimize her chances of conceiving by timing intercourse. They can also reduce the effects of unidentified ovulation issues and may help in cases of unexplained infertility. 
Although drugs can work miracles, they can’t treat some causes of infertility. In cases like this, options such as assisted conception would then likely be recommended by a doctor. The most common methods being IUI and IVF. With treatment such as IVF, a woman’s egg is fertilized outside of the body. Before this, fertility medicine is taken to encourage the ovaries to produce more eggs than they usually would. Eggs are then removed from the ovaries and fertilized with sperm in a laboratory. The fertilized egg is then returned to the womb to grow and develop. 
If none of the above can work due to a blockage in the fallopian tubes – often caused by small amounts of scar tissue or adhesions – a doctor can use laparoscopic surgery to remove the blockage and open the tubes.