In the UK, previous NICE guidelines defined infertility as failure to conceive after regular unprotected sexual intercourse for two years in the absence of known reproductive pathology.[11] Updated NICE guidelines do not include a specific definition, but recommend that "A woman of reproductive age who has not conceived after 1 year of unprotected vaginal sexual intercourse, in the absence of any known cause of infertility, should be offered further clinical assessment and investigation along with her partner, with earlier referral to a specialist if the woman is over 36 years of age."[12]
These time intervals would seem to be reversed; this is an area where public policy trumps science. The idea is that for women beyond age 35, every month counts and if made to wait another six months to prove the necessity of medical intervention, the problem could become worse. The corollary to this is that, by definition, failure to conceive in women under 35 isn't regarded with the same urgency as it is in those over 35.
Epigenetic testing may allow patients to forgo the cost of multiple rounds of IVF by predicting whether embryos will fail. Equipped with this information, couples can have their IVF cycles optimized to account for embryonic versus fertilization issues. This represents a significant leap for the medical community given that 36% of couples struggling with unexplained infertility are currently over-treated.
In IVF, a woman is given more medications to develop lots of eggs. Ideally, they develop around 15 mature eggs. The eggs are removed from the ovaries, fertilized and developed in a lab for a number of days, and subsequently put back into the uterus as an early-stage embryo. While this may sound like a relatively minor difference, it leads to leads to a large number of noteworthy differences.
For women, problems with fertilisation arise mainly from either structural problems in the Fallopian tube or uterus or problems releasing eggs. Infertility may be caused by blockage of the Fallopian tube due to malformations, infections such as chlamydia or scar tissue. For example, endometriosis can cause infertility with the growth of endometrial tissue in the Fallopian tubes or around the ovaries. Endometriosis is usually more common in women in their mid-twenties and older, especially when postponed childbirth has taken place.[55]

While I’m not on the list to receive a Nobel Prize for mathematics any time soon, I do have enough understanding of how probabilities work to know that roulette isn’t a very viable long term career choice. Figuring that if I could make this costly error in analysis, there must be at least a few others out there that have, or will, make the same mistake as me…

Men will need to have sperm testing. This involves giving a semen sample, which a lab will analyze for the number, size, and shape of the sperm. If the sperm are weak or damaged, a procedure called intracytoplasmic sperm injection (ICSI) may be necessary. During ICSI, a technician injects sperm directly into the egg. ICSI can be part of the IVF process.
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.
Talk it out. Once you realize you’re entitled to your emotions, find an outlet for them. Talking about your feelings and your struggles can be a huge release and allow you to receive the support you need. If your family or friends don’t understand your sadness (or you find it hard to contain your baby envy around friends with more than one child), seek out people in your same situation. Find a support group for people with secondary infertility — online or in your area. And consider joining WTE's Trying to Conceive group to find moms who are also coping with secondary infertility.
Undergo minor surgery to retrieve eggs. Following a round of injections, your doctor will determine the best date to retrieve eggs from the follicles of your ovaries. If you choose to use donor eggs, the retrieval process will occur with the donor, or the frozen eggs may be collected and used. A partner’s sperm or donor sperm will also be collected.
Abdominal adhesions (scar tissue) bands of scar tissue that form between abdominal organs and tissues. Symptoms of abdominal adhesions are pelvic or abdominal pain. Abdominal adhesions on the intestines can cause bowel obstruction, which is a medical emergency. Treatment for abdominal adhesions is generally surgery to cut the adhesions away from the internal tissues and organs. There is no way to prevent abdominal adhesions.
When transferring more than one embryo, the risk of pregnancy and newborn complications also increases.1 Among IVF babies, twins are 12 times more likely than singletons to be delivered prematurely, 16 times more likely to be underweight and 5 times more likely to suffer from respiratory complications. Among IVF mothers, mothers of twins are 2.5 times more likely to have pre-eclampsia, over 8 times more likely to have premature preterm rupture of membranes and 4 times more likely to require a Caesarean section.
Alternatives to donating unused embryos are destroying them (or having them implanted at a time where pregnancy is very unlikely),[90] keeping them frozen indefinitely, or donating them for use in research (which results in their unviability).[91] Individual moral views on disposing leftover embryos may depend on personal views on the beginning of human personhood and definition and/or value of potential future persons and on the value that is given to fundamental research questions. Some people believe donation of leftover embryos for research is a good alternative to discarding the embryos when patients receive proper, honest and clear information about the research project, the procedures and the scientific values.[92]

In IUI, this natural sequence of events is given some assistance. A sample of sperm is prepared in the laboratory so that only the best moving sperm are concentrated together. This sperm is then deposited directly into the uterus without having to swim there on its own, which can be challenging, especially if the sperm do not swim well. IUI places a higher concentration of moving sperm closer to the ovulated egg. Often a woman will have taken medication prior to the IUI procedure to ensure she will ovulate around the time of the procedure, so egg and sperm can meet.

When you face secondary infertility, you’re dealing not only with the typical ups and downs of TTC, but also with the additional emotional fallout that is unique to those having difficulty getting pregnant with baby number two. In addition to feeling disappointed and upset, you may also be feeling shock (“I got pregnant so easily the first time, there’s no way I could have infertility problems”), guilt (“I already have a child, so I should be happy”) and even isolation (“I can’t connect with the people facing primary infertility and I can’t connect with my friends who have multiple kids”). How do you reconcile these conflicting emotions — and how do you tackle them while trying to raise the child you already have?
A review in 2013 came to the result that infants resulting from IVF (with or without ICSI) have a relative risk of birth defects of 1.32 (95% confidence interval 1.24–1.42) compared to naturally conceived infants.[48] In 2008, an analysis of the data of the National Birth Defects Study in the US found that certain birth defects were significantly more common in infants conceived through IVF, notably septal heart defects, cleft lip with or without cleft palate, esophageal atresia, and anorectal atresia; the mechanism of causality is unclear.[49] However, in a population-wide cohort study of 308,974 births (with 6,163 using assisted reproductive technology and following children from birth to age five) researchers found: "The increased risk of birth defects associated with IVF was no longer significant after adjustment for parental factors." [50] Parental factors included known independent risks for birth defects such as maternal age, smoking status, etc. Multivariate correction did not remove the significance of the association of birth defects and ICSI (corrected odds ratio 1.57), although the authors speculate that underlying male infertility factors (which would be associated with the use of ICSI) may contribute to this observation and were not able to correct for these confounders. The authors also found that a history of infertility elevated risk itself in the absence of any treatment (odds ratio 1.29), consistent with a Danish national registry study [51] and "implicates patient factors in this increased risk." The authors of the Danish national registry study speculate: "our results suggest that the reported increased prevalence of congenital malformations seen in singletons born after assisted reproductive technology is partly due to the underlying infertility or its determinants."

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.