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 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]
Artificial insemination, including intracervical insemination and intrauterine insemination of semen. It requires that a woman ovulates, but is a relatively simple procedure, and can be used in the home for self-insemination without medical practitioner assistance.[171] The beneficiaries of artificial insemination are women who desire to give birth to their own child who may be single, women who are in a lesbian relationship or women who are in a heterosexual relationship but with a male partner who is infertile or who has a physical impairment which prevents full intercourse from taking place.
The percentage of cycles cancelled between egg retrieval and embryo transfer is an indication of failed fertilization. This figure is halved with ICSI as compared to conventional IVF, indicating that it can indeed improve fertilization when the sperm is at fault. However, there are no differences in pregnancy, miscarriage or live birth rates between conventional IVF and ICSI, indicating overall similar success rates1.
Most women over 40 who try to get pregnant will have difficulty, and fertility over age 44 is rare - even in women who are ovulating regularly every month. The point is that the older the female partner, the more likely that there is an egg related issue causing the fertility problem. Unfortunately, there is currently no specific test for "egg quality".
Success rates for IVF depend on a number of factors, including the reason for infertility, where you're having the procedure done, and your age. The CDC compiles national statistics for all assisted reproductive technology (ART) procedures performed in the U.S., including IVF, GIFT, and ZIFT, although IVF is by far the most common; it accounts for 99% of the procedures. The most recent report from 2016 found:
Gathering the eggs. Your doctor gives you an anesthetic and inserts an ultrasound probe through your vagina to look at your ovaries and identify the follicles. A thin needle is then inserted through the vaginal wall to remove the eggs from the follicles. Eight to 15 eggs are usually retrieved. You may have some cramping and spotting for a few days afterward, but most women feel better in a day or two.

Every woman is born with a set number of eggs, which declines as she ages. To get pregnant, an egg released from a woman’s ovaries must be fertilized by sperm, travel down the fallopian tube, and attach to the side of her uterus. At any stage along the way, a problem may occur, resulting in a case of infertility. For women, the most common causes of infertility are primary ovarian insufficiency (early menopause), ovulation disorders affecting egg release, uterine or cervical abnormalities, endometriosis (where tissue grows outside of the uterus), fallopian tube blockage or damage, polycystic ovary syndrome, and various hormonal imbalances. Certain cancers and their treatments can also negatively impact a woman’s fertility.
Impaired sperm production or function. Below-average sperm concentration, weak movement of sperm (poor mobility), or abnormalities in sperm size and shape can make it difficult for sperm to fertilize an egg. If semen abnormalities are found, your partner might need to see a specialist to determine if there are correctable problems or underlying health concerns.
Treatment with Clomid tablets plus IUI improves fertility rates. For unexplained infertility, studies have shown that for women under 35, monthly success rates for Clomid plus insemination are about 10% per cycle. This pregnancy rate holds up for about 3 tries and the success rate is considerably lower after that. More about success rates with IUIs is on the insemination page and on the Clomid for unexplained infertility page. The insemination component boosts fertility more than the Clomid does - but success rates are higher when both are used together.
Unfortunately, a couple cannot look at the TMC from a semen analysis and know precisely where they fit into this rubrik. That is because the TMCs recorded above were measured after the man already had his sperm washed for IUI. A sperm wash can lower TMCs by roughly 30% and a credible rule of thumb for a general estimate would be to take the “pre-wash” TMC from a semen analysis, subtract a third, then presume that will be the “post-wash” TMC and apply it to the above charts.
As with any medical procedure, there are some risks to keep in mind. When choosing between IUI and IVF, the risk is certainly something to consider. The chances of experiencing either a miscarriage or multiples are concerns many have when deciding to undergo fertility treatments. So let’s take a look at the odds of either of these things occurring, plus a few other risks to be aware of.
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.
Give in to the grief. While you probably feel incredibly disappointed and sad about your infertility problems, you may feel guilty giving in to those emotions. Parents facing secondary infertility often feel they don’t have the “right” to feel sad about their struggles because they should be grateful for the child they already have. But if you want more children and are having trouble getting pregnant again, you are just as entitled as anyone else to feel depressed or angry. The last thing you need when you’re coping with secondary infertility is to let guilt weigh you down even more.
Use our website links to find your nearest clinic, or fill out our online contact form. You may want to discuss the pros and cons of IUI and IVF or you may just want to explore all the options that might be available. The sooner you take that first step to discuss your fertility issues with one of our physicians, the sooner you can decide on the next step in your fertility journey and take one step closer to achieving your dream of holding your own new baby in your arms.
Additionally, couples may turn to assisted reproductive technology, the most common of which is in vitro fertilization (IVF). Other techniques may include special injections or using a donor's eggs or sperm. Complications can sometimes occur, the most common being bleeding or infection; ovarian hyperstimulation syndrome, in which the ovaries become swollen and painful; and multiple pregnancies.
Endometriosis and infertility are often related, but treating this pelvic inflammatory disorder can improve your chances of pregnancy. Here’s a description of what causes endometriosis, the symptoms of endometriosis, and what to do if you suspect you have this pelvic disorder. According to Harvard Medical School, endometriosis is responsible for many cases of infertility, there… Read More »Endometriosis and Infertility – How a Pelvic Disorder Affects Pregnancy
ART techniques generally start with stimulating the ovaries to increase egg production. After stimulation, the physician surgically extracts one or more eggs from the ovary, and unites them with sperm in a laboratory setting, with the intent of producing one or more embryos. Fertilization takes place outside the body, and the fertilized egg is reinserted into the woman's reproductive tract, in a procedure called embryo transfer.
In the US, up to 20% of infertile couples have unexplained infertility. In these cases abnormalities are likely to be present but not detected by current methods. Possible problems could be that the egg is not released at the optimum time for fertilization, that it may not enter the fallopian tube, sperm may not be able to reach the egg, fertilization may fail to occur, transport of the zygote may be disturbed, or implantation fails. It is increasingly recognized that egg quality is of critical importance and women of advanced maternal age have eggs of reduced capacity for normal and successful fertilization. Also, polymorphisms in folate pathway genes could be one reason for fertility complications in some women with unexplained infertility.[59] However, a growing body of evidence suggests that epigenetic modifications in sperm may be partially responsible.[60][61]
In humans, infertility is the inability to become pregnant after one year of intercourse without contraception involving a male and female partner.[2] There are many causes of infertility, including some that medical intervention can treat.[3] Estimates from 1997 suggest that worldwide about five percent of all heterosexual couples have an unresolved problem with infertility. Many more couples, however, experience involuntary childlessness for at least one year: estimates range from 12% to 28%.[4] Male infertility is responsible for 20–30% of infertility cases, while 20–35% are due to female infertility, and 25–40% are due to combined problems in both parts.[2][5] In 10–20% of cases, no cause is found.[5] The most common cause of female infertility is ovulatory problems, which generally manifest themselves by sparse or absent menstrual periods.[6] Male infertility is most commonly due to deficiencies in the semen, and semen quality is used as a surrogate measure of male fecundity.[7]
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.

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."
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.