Some research has found that IVF may raise the risk of some very rare birth defects, but the risk is still relatively low. Research has also found that the use of ICSI with IVF, in certain cases of male infertility, may increase the risk of infertility and some sexual birth defects for male children. This risk, however, is very low (less than 1%).
In egg donation and embryo donation, the resultant embryo after fertilisation is inserted in another woman than the one providing the eggs. These are resources for women with no eggs due to surgery, chemotherapy, or genetic causes; or with poor egg quality, previously unsuccessful IVF cycles or advanced maternal age. In the egg donor process, eggs are retrieved from a donor's ovaries, fertilised in the laboratory with the sperm from the recipient's partner, and the resulting healthy embryos are returned to the recipient's uterus.
Bloating: Fertility medications can heavily impact how your body retains water, leading to the dreaded side effect of bloating. This is especially common in your midsection, where fluid can build up near the ovaries (creating abdominal tenderness, too). You can combat bloating by increasing your fluid intake and participating in light exercise such as walking.
Obesity: The obesity epidemic has recently become is a serious issue, particularly in industrialized nations. The rising number of obese individuals may be due in part to an energy-rich diet as well as insufficient physical exercise.  In addition to other potential health risks, obesity can have a significant impact on male and female fertility. BMI (body mass index) may be a significant factor in fertility, as an increase in BMI in the male by as little as three units can be associated with infertility. Several studies have demonstrated that an increase in BMI is correlated with a decrease in sperm concentration, a decrease in motility and an increase DNA damage in sperm. A relationship also exists between obesity and erectile dysfunction (ED). ED may be the consequence of the conversion of androgens to estradiol. The enzyme aromatase is responsible for this conversion, and is found primarily in adipose tissue. As the amount of adipose tissue increases, there is more aromatase available to convert androgens, and serum estradiol levels increase. Other hormones including inhibin B and leptin, may also be affected by obesity. Inhibin B levels have been reported to decrease with increasing weight, which results in decreased Sertoli cells and sperm production. Leptin is a hormone associated with numerous effects including appetite control, inflammation, and decreased insulin secretion, according to many studies. Obese women have a higher rate of recurrent, early miscarriage compared to non-obese women.
Perhaps except for infertility in science fiction, films and other fiction depicting emotional struggles of assisted reproductive technology have had an upswing first in the later part of the 2000s decade, although the techniques have been available for decades.[72] Yet, the number of people that can relate to it by personal experience in one way or another is ever growing, and the variety of trials and struggles is huge.[72]

Problems with the uterus: There are many conditions related to the uterus that can cause secondary infertility. Scarring can occur during a dilation and curettage (D&C) or Cesarean delivery that can create adhesions inside the uterus that interfere with future pregnancies Fibroids or polyps are benign (non-cancer) growths inside the uterus that can impair pregnancy. A retained placenta can cause infection and uterine scarring.
According to the data collected for 2014, these are the IVF success rates nationally, when using non-donor eggs, per egg retrieval. (These are not per cycle. In other words, these are the odds of a live birth after one egg retrieval, which may mean conception with fresh eggs/embryos in the cycle of the egg retrieval ​or after a frozen embryo transfer cycle in the following months.) 
Fertility expert Zita West has noticed this increase at her London clinic. "The main reason," she explains, "is age. Women are having babies later." Exhaustion also plays a part. "The sleeplessness of life with a small child can't be underestimated," she says. "You might still be breastfeeding, you might be sharing a bed with a toddler, you might be holding down a job at the same time. Basically, there's not a lot of sex happening."
Endometriosis implants are most commonly found on the ovaries, the Fallopian tubes, outer surfaces of the uterus or intestines, and on the surface lining of the pelvic cavity. They also can be found in the vagina, cervix, and bladder. Endometriosis may not produce any symptoms, but when it does the most common symptom is pelvic pain that worsens just prior to menstruation and improves at the end of the menstrual period. Other symptoms of endometriosis include pain during sex, pain with pelvic examinations, cramping or pain during bowel movements or urination, and infertility. Treatment of endometriosis can be with medication or surgery.
Studies show that sperm count and sperm movement decrease as men age, as does sexual function. But there isn't a cutoff age that makes a man too old to father a child. One study found that it took men age 45 or older longer to get a woman pregnant once the couple started trying. If your partner is older, you may want to talk to your doctor about ways to boost your chances.
The Fallopian tubes are the site for fertilization before the embryo makes its way to the uterine cavity for implantation. If the Fallopian tubes are damaged, fertilization may not occur. If one Fallopian tube is blocked, it may be due to inherent disease involving both Fallopian tubes; even if the other Fallopian tube is open, it may not be able to provide the appropriate nurturing environment for fertilization and early embryo growth to take place.
Any embryos that you do not use in your first IVF attempt can be frozen for later use. This will save you money if you undergo IVF a second or third time. If you do not want your leftover embryos, you may donate them to another infertile couple, or you and your partner can ask the clinic to destroy the embryos. Both you and your partner must agree before the clinic will destroy or donate your embryos.

The Rand Consulting Group has estimated there to be 400,000 frozen embryos in the United States in 2006.[83] The advantage is that patients who fail to conceive may become pregnant using such embryos without having to go through a full IVF cycle. Or, if pregnancy occurred, they could return later for another pregnancy. Spare oocytes or embryos resulting from fertility treatments may be used for oocyte donation or embryo donation to another woman or couple, and embryos may be created, frozen and stored specifically for transfer and donation by using donor eggs and sperm. Also, oocyte cryopreservation can be used for women who are likely to lose their ovarian reserve due to undergoing chemotherapy.[84]

The likelihood of a diagnosis of unexplained infertility is increased substantially in women 35 and over - and greatly increased in women over 38. The reason for this is that there are more likely to be egg quantity and quality problems as women age. Since we do not have a "standard category" called egg factor infertility, these couples sometimes get lumped in to the "unexplained" infertility category.
Secondary infertility can be traced to either partner or both partners. About one-third of cases originate in women and about one-third originate in men. In the remaining one-third, the cause is due to a combination of factors or isn’t known. Increased age, complications from a prior pregnancy or surgery, increased weight, medications, sexually transmitted diseases, impaired sperm production, alcohol abuse, and smoking are all examples of secondary infertility in women and men.
If you’re worried that you might be an infertile woman, don’t lose your hope. Be encouraged, and know that many women get pregnant even after being diagnosed with infertility. Know that there is a reason for what you’re going through. I trust God and I rely on His power, peace, and joy every day. I know there is a reason why we struggled with infertility – and perhaps the reason is so I could write about fertility and encourage couples like you to keep the faith.

3. Painful Periods: We’re not talking about normal cramping here. But, severe pain that stops you in your tracks and even causes nausea or vomiting. Alone this may not be a sign of infertility, but combined with other symptoms like pain during intercourse, blood in the urine or during bowel movements, or irregular periods, can be signs of endometriosis–a condition that accounts for 20-40% of female infertility cases.
When the ovarian follicles have reached a certain degree of development, induction of final oocyte maturation is performed, generally by an injection of human chorionic gonadotropin (hCG). Commonly, this is known as the "trigger shot."[67] hCG acts as an analogue of luteinising hormone, and ovulation would occur between 38 and 40 hours after a single HCG injection,[68] but the egg retrieval is performed at a time usually between 34 and 36 hours after hCG injection, that is, just prior to when the follicles would rupture. This avails for scheduling the egg retrieval procedure at a time where the eggs are fully mature. HCG injection confers a risk of ovarian hyperstimulation syndrome. Using a GnRH agonist instead of hCG eliminates most of the risk of ovarian hyperstimulation syndrome, but with a reduced delivery rate if the embryos are transferred fresh.[69] For this reason, many centers will freeze all oocytes or embryos following agonist trigger.
SART, in conjunction with, The American Society for Reproductive Medicine (ASRM), has published guidelines for the recommended number of embryos to transfer (add to link). These guidelines are based on SART-sponsored research which continually evaluates success rates around the country.  This helps to determine the optimal number of embryos to transfer, based on specific patient characteristics, like age and history of prior IVF.  Patients may require several cycles of treatment to have a baby. Success rates remain fairly constant over several cycles, but may vary greatly between individuals.  

The Fallopian tubes are the site for fertilization before the embryo makes its way to the uterine cavity for implantation. If the Fallopian tubes are damaged, fertilization may not occur. If one Fallopian tube is blocked, it may be due to inherent disease involving both Fallopian tubes; even if the other Fallopian tube is open, it may not be able to provide the appropriate nurturing environment for fertilization and early embryo growth to take place.
In order for pregnancy to happen, sperm has to meet the egg. This normally takes place at the end of the fallopian tube, and this is called fertilization. There are a number of obstacles that can prevent this from happening, and the process itself even in healthy young fertile women is very complex- hence the low pregnancy rate each month. Obstacles such as cycle timing, low sperm count, poor sperm motility, blocked fallopian tubes, or endometriosis must be overcome to achieve a pregnancy. Timing is often the most common obstacle to conception. What does it mean for you when common causes of infertility are ruled out and you’re told you have unexplained infertility? It should mean a time of hope.