"Demographers tend to define infertility as childlessness in a population of women of reproductive age," whereas "the epidemiological definition refers to "trying for" or "time to" a pregnancy, generally in a population of women exposed to" a probability of conception.[8] Currently, female fertility normally peaks at age 24 and diminishes after 30, with pregnancy occurring rarely after age 50.[9] A female is most fertile within 24 hours of ovulation.[9] Male fertility peaks usually at age 25 and declines after age 40.[9] The time needed to pass (during which the couple tries to conceive) for that couple to be diagnosed with infertility differs between different jurisdictions. Existing definitions of infertility lack uniformity, rendering comparisons in prevalence between countries or over time problematic. Therefore, data estimating the prevalence of infertility cited by various sources differs significantly.[8] A couple that tries unsuccessfully to have a child after a certain period of time (often a short period, but definitions vary) is sometimes said to be subfertile, meaning less fertile than a typical couple. Both infertility and subfertility are defined as the inability to conceive after a certain period of time (the length of which vary), so often the two terms overlap.
During the selection and transfer phases, many embryos may be discarded in favour of others. This selection may be based on criteria such as genetic disorders or the sex.[125] One of the earliest cases of special gene selection through IVF was the case of the Collins family in the 1990s, who selected the sex of their child.[126] The ethic issues remain unresolved as no consensus exists in science, religion, and philosophy on when a human embryo should be recognised as a person. For those who believe that this is at the moment of conception, IVF becomes a moral question when multiple eggs are fertilised, begin development, and only a few are chosen for implantation.[citation needed]
Secondary infertility (SI) is defined by doctors as the inability to conceive or carry to term a second or subsequent child. You may not have heard of it but you probably soon will, because it's on the increase. A US study revealed that, in 1995, 1.8 million women suffered from secondary infertility; in 2006, it was 3.3 million. SI now accounts for six out of 10 infertility cases.
For women, intake of antioxidants (such as N-acetyl-cysteine, melatonin, vitamin A, vitamin C, vitamin E, folic acid, myo-inositol, zinc or selenium) has not been associated with a significantly increased live birth rate or clinical pregnancy rate in IVF according to Cochrane reviews.[30] The review found that oral antioxidants given to men in couples with male factor or unexplained subfertility may improve live birth rates, but more evidence is needed.[30]
Wondering if it’s time to seek fertility help from a specialist? Your age can help clue you in to the answer. If you’re younger than 35, it’s perfectly normal for it to take six months to a year to conceive. If, after a year, you haven’t accomplished your conception goal, you’ll want to talk with your practitioner and/or get a referral to a fertility specialist. If you’re older than 35, experts recommend that you seek help from a fertility specialist after six months of regularly trying to conceive without birth control — and you may even want to go after three months. If you’re over 40, you’ll probably want to start off your quest for a second pregnancy with a fertility evaluation from your doctor. Ditto if your partner is over 40, since 35 to 40 percent of fertility problems can be traced back to the man, and a guy’s age affects the quality of his sperm.
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.
Intercourse must take place frequently, particularly before and around the time of ovulation, and the couple must have been trying to conceive for at least one year (6 months if the woman is over 35 years old). Using these criteria, about 10-20% of all infertile couples have unexplained infertility. However, the percentage of couples classified as having unexplained infertility will depend upon the thoroughness of testing and the sophistication of medical technology. 
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. 

A risk of ovarian stimulation is the development of ovarian hyperstimulation syndrome, particularly if hCG is used for inducing final oocyte maturation. This results in swollen, painful ovaries. It occurs in 30% of patients. Mild cases can be treated with over the counter medications and cases can be resolved in the absence of pregnancy. In moderate cases, ovaries swell and fluid accumulated in the abdominal cavities and may have symptoms of heartburn, gas, nausea or loss of appetite. In severe cases patients have sudden excess abdominal pain, nausea, vomiting and will result in hospitalisation.

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.
In males with hepatitis B, The Practice Committee of the American Society for Reproductive Medicine advises that sperm washing is not necessary in IVF to prevent transmission, unless the female partner has not been effectively vaccinated.[37][38] In females with hepatitis B, the risk of vertical transmission during IVF is no different from the risk in spontaneous conception.[38] However, there is not enough evidence to say that ICSI procedures are safe in females with hepatitis B in regard to vertical transmission to the offspring.[38]

Consider your health status. Have you started any medications that might be interfering with conception? What about a change in your health status (a new chronic condition that’s cropped up since your first baby was born, for instance)? Any changes to your health could be putting a dent in your conception plans. Perhaps some simple health modifications — like switching to a more fertility-friendly medication, for instance, or getting your chronic condition under control — could bring you closer to the second baby of your dreams.
Mild IVF[64] is a method where a small dose of ovarian stimulating drugs are used for a short duration during a woman's natural cycle aimed at producing 2–7 eggs and creating healthy embryos. This method appears to be an advance in the field to reduce complications and side-effects for women and it is aimed at quality, and not quantity of eggs and embryos. One study comparing a mild treatment (mild ovarian stimulation with GnRH antagonist co-treatment combined with single embryo transfer) to a standard treatment (stimulation with a GnRH agonist long-protocol and transfer of two embryos) came to the result that the proportions of cumulative pregnancies that resulted in term live birth after 1 year were 43.4% with mild treatment and 44.7% with standard treatment.[65] Mild IVF can be cheaper than conventional IVF and with a significantly reduced risk of multiple gestation and OHSS.[66]
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.
Risk of ovarian hyperstimulation syndrome (OHSS). OHSS can happen when women respond too well to fertility drugs and produce too many eggs. About 10 to 20 percent of women who take gonadotropins develop a mild form of OHSS, a condition marked by weight gain and a full, bloated feeling. Some also have shortness of breath, dizziness, pelvic pain, nausea, and vomiting. If you have OHSS, your ovaries swell to several times the normal size and produce fluid that accumulates in your abdominal cavity. Normally this resolves itself with careful monitoring by a physician and bed rest. But in rare cases it's life threatening, and you may have to be hospitalized for more intensive monitoring or treatment.

Infertility can have a profound impact on one’s mental health. When men and women find out that they can’t conceive, they may experience the same painful emotions as anyone coping with grief or profound loss. Common reactions include shock, frustration, grief, anger, decreased self-esteem, anxiety, and depression, but feelings about infertility can vary greatly depending on the source of the problems. Men, in particular, find it far easier to deal with a partner’s infertility than with their own.
Antiphospholipid syndrome (phospholipid antibody syndrome or Hughes syndrome) is an immune system disorder with symptoms that include: excessive blood clotting, miscarriages unexplained fetal death, or premature birth. In antiphospholipid syndrome, these symptoms are accompanied by the presence of antiphospholipid antibodies (cardiolipin or lupus anticoagulant antibodies) in the blood. Treatment focuses on preventing clotting by thinning the blood with the use of anticoagulants and aspirin.

Risk of multiples. IUI with fertility medication carries a significant risk of multiple pregnancies, including higher-order multiples (triplets or more). A good clinic will carefully monitor your follicles to make sure that only a safe number are mature before the IUI, but they cannot entirely eliminate the risk. Recent advances in IVF (including blastocyst transfer) mean that most modern fertility clinics now transfer only one or two embryos per IVF cycle. As a result, the risk of multiple pregnancies for IVF patients is much lower than it used to be.
Most couples develop a willingness to conceive a child at some point in their life. Generally, couples conceive within the first year, and around 7% of couples conceive in the second year. The inability to conceive within 12 months is defined as infertility. It is recommended to seek help from a reproductive endocrinologist if you are unable to conceive within 12 months. Our modern technology in healthcare has opened a lot of options for women who are facing infertility issues.
The stress of secondary infertility on an individual's life and relationships can be significant. It can be hard to find support from family and friends, especially when a woman or couple already has/have children. Sentiments such as, "you should be grateful for what you have," or, "just keep trying," almost never serve as useful advice or support. Couples and single parents can even experience resentment from other couples with infertility who are unable to even have their first child.

1. Educating About Infertility - Educating yourself about infertility is the first step towards your treatment. We believe that educating the patients about the problem associated with their pregnancy and the available treatment options can empower them to make better choices. When you understand better about the reproductive process, you will be able to decide when to seek help. We aim to achieve a healthy pregnancy for every patient.
^ Manheimer E, van der Windt D, Cheng K, Stafford K, Liu J, Tierney J, Lao L, Berman BM, Langenberg P, Bouter LM (2013). "The effects of acupuncture on rates of clinical pregnancy among women undergoing in vitro fertilization: a systematic review and meta-analysis". Human Reproduction Update. 19 (6): 696–713. doi:10.1093/humupd/dmt026. PMC 3796945. PMID 23814102.
We don't know what causes most cases of secondary infertility, says Jamie Grifo, M.D., Ph.D., program director of the New York University Fertility Center, in New York City. "The majority of the time, though, it reflects the fact that you're older now, so it's simply more difficult to get pregnant." The reality is that for women, fertility peaks at age 25 and drops by half between ages 30 and 40. As we age, egg quality declines and we're more likely to develop fibroids and endometriosis, which contribute to infertility. Other factors such as adding extra weight, taking new meds, or having surgery since your last pregnancy can be an issue. It may also be that your partner's sperm quality or production is now poor.
The AMIGOS study suggested that clomid provided the best balance of a high pregnancy rate with a reasonably low multiple rate among couples with unexplained infertility. However, the authors of the Huang study concluded that on balance letrozole was better. From our vantage point, given that clomid more commonly causes multiple eggs to be ovulated, it seems like the slightly better option between the two because the whole point of treatment in unexplained infertility patients is to increase the odds of delivery by increasing the number of eggs ovulated.

During the second half of your menstrual cycle, the hormone progesterone kicks in to help prepare the lining of your uterus for a fertilized egg. If the egg isn't fertilized and doesn't implant, it disintegrates, progesterone levels fall, and about 12 to 16 days later, the egg -- along with blood and tissues from the lining of the uterus -- is shed from the body. That process is menstruation. It usually lasts 3 to 7 days.
Addressing lifestyle issues is not meant to be a quick fix, and typically does not lead to instant success. However, with unexplained infertility every little bit counts, so don’t fret or give up. Do not assume just because the cause of infertility is unexplained, it is untreatable or there is no pathway to parenthood. When a specific cause is not determined for women, and male infertility has also been ruled out, our fertility specialist may begin a course of treatment to improve the chances of conception and pregnancy. The speed with which interventions are offered depends on each individual’s own needs and desires as determined by age and other factors.
×