The number to be transferred depends on the number available, the age of the woman and other health and diagnostic factors. In countries such as Canada, the UK, Australia and New Zealand, a maximum of two embryos are transferred except in unusual circumstances. In the UK and according to HFEA regulations, a woman over 40 may have up to three embryos transferred, whereas in the US, there is no legal limit on the number of embryos which may be transferred, although medical associations have provided practice guidelines. Most clinics and country regulatory bodies seek to minimise the risk of multiple pregnancy, as it is not uncommon for multiple embryos to implant if multiple embryos are transferred. Embryos are transferred to the patient's uterus through a thin, plastic catheter, which goes through her vagina and cervix. Several embryos may be passed into the uterus to improve chances of implantation and pregnancy.
From the What to Expect editorial team and Heidi Murkoff, author of What to Expect Before You’re Expecting. Health information on this site is based on peer-reviewed medical journals and highly respected health organizations and institutions including ACOG (American College of Obstetricians and Gynecologists), CDC (Centers for Disease Control and Prevention) and AAP (American Academy of Pediatrics), as well as the What to Expect books by Heidi Murkoff.
Male infertility may be caused by trouble with sperm delivery due to structural difficulties like testicle blockage or damage to the reproductive organs, sexual function concerns such as premature ejaculation, or genetic conditions including cystic fibrosis. Another root of male infertility may be abnormal sperm function or production, often due to genetic defects or health problems including diabetes or certain sexually transmitted diseases. Other risk factors include overexposure to certain environmental factors, such as alcohol, cigarette or marijuana smoke, chemicals, and pesticides, as well as frequent exposure to high temperatures (hot tubs and saunas). Specific cancers and their treatments can also be harmful to male fertility.
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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.
Within the Orthodox Jewish community the concept is debated as there is little precedent in traditional Jewish legal textual sources. Regarding laws of sexuality, religious challenges include masturbation (which may be regarded as "seed wasting"[129]), laws related to sexual activity and menstruation (niddah) and the specific laws regarding intercourse. An additional major issue is that of establishing paternity and lineage. For a baby conceived naturally, the father's identity is determined by a legal presumption (chazakah) of legitimacy: rov bi'ot achar ha'baal – a woman's sexual relations are assumed to be with her husband. Regarding an IVF child, this assumption does not exist and as such Rabbi Eliezer Waldenberg (among others) requires an outside supervisor to positively identify the father.[133] Reform Judaism has generally approved IVF.[129]
If IVF were to involve the fertilisation of only a single egg, or at least only the number that will be implanted, then this would not be an issue. However, this has the chance of increasing costs dramatically as only a few eggs can be attempted at a time. As a result, the couple must decide what to do with these extra embryos. Depending on their view of the embryo's humanity or the chance the couple will want to try to have another child, the couple has multiple options for dealing with these extra embryos. Couples can choose to keep them frozen, donate them to other infertile couples, thaw them, or donate them to medical research.[90] Keeping them frozen costs money, donating them does not ensure they will survive, thawing them renders them immediately unviable, and medical research results in their termination. In the realm of medical research, the couple is not necessarily told what the embryos will be used for, and as a result, some can be used in stem cell research, a field perceived to have ethical issues.
There are many studies comparing success rates between clomid, letrozole, or gonadotropins for patients with unexplained infertility, but two stand out as the best and most informative. The first study was conducted at multiple sites across the country and was termed the AMIGOS trial. In this study, gonadotropins produced the highest pregnancy rate, followed by clomid, and then letrozole. However, almost one third of all pregnancies in the gonadotropin arm was either a twin or triplet gestation. This was significantly higher than the clomid or letrozole arms.
Initial blood work, cycle tracking and fertility analysis is done. To begin IVF, your doctor or fertility specialist will evaluate your hormone levels and menstrual cycle to determine what medications and plan of action may be needed. You may also undergo a transvaginal ultrasound to examine your ovaries and reproductive system, ensuring that they are healthy.
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?
Are you infertile, or just having trouble getting pregnant? If you go to the doctor, here’s how a diagnosis of infertility will happen. “Infertility” is a term that describes when a couple is unable to conceive a child after a year of having sex without birth control. In women who are older than age 35, infertility… Read More »How Doctors Diagnose Infertility
Kym Campbell is a Health Coach and PCOS expert with a strong passion for using evidence-based lifestyle interventions to manage this disorder. Kym combines rigorous scientific analysis with the advice from leading clinicians to disseminate the most helpful PCOS patient-centric information you can find online. You can read more about Kym and her team here.

Complexity. IUI refers to one procedure. Prepared sperm is placed directly in the patient’s uterus when she is ovulating in order to aid fertilization. IUI may be performed in sync with a woman’s natural cycle or timed with fertility medications to stimulate ovulation. IVF, on the other hand, is a process which consists of several stages and requires more than one procedure: first the ovaries are stimulated using a series of fertility medications, then the patient undergoes egg retrieval in a day procedure under a mild anesthetic, then after embryos have been created and incubated in the lab, they are placed directly into her uterus in the embryo transfer procedure. Even with the use of fertility drugs, going through IUI is less physically demanding than undergoing IVF.


Low weight: Obesity is not the only way in which weight can impact fertility. Men who are underweight tend to have lower sperm concentrations than those who are at a normal BMI. For women, being underweight and having extremely low amounts of body fat are associated with ovarian dysfunction and infertility and they have a higher risk for preterm birth. Eating disorders such as anorexia nervosa are also associated with extremely low BMI. Although relatively uncommon, eating disorders can negatively affect menstruation, fertility, and maternal and fetal well-being.

Prior to the retrieval procedure, you will be given injections of a medication that ripens the developing eggs and starts the process of ovulation. Timing is important; the eggs must be retrieved just before they emerge from the follicles in the ovaries. If the eggs are taken out too early or too late, they won't develop normally. Your doctor may do blood tests or an ultrasound to be sure the eggs are at the right stage of development before retrieving them. The IVF facility will provide you with special instructions to follow the night before and the day of the procedure. Most women are given pain medication and the choice of being mildly sedated or going under full anesthesia.
Progesterone elevation on the day of induction of final maturation is associated with lower pregnancy rates in IVF cycles in women undergoing ovarian stimulation using GnRH analogues and gonadotrophins.[23] At this time, compared to a progesterone level below 0.8 ng/ml, a level between 0.8 and 1.1 ng/ml confers an odds ratio of pregnancy of approximately 0.8, and a level between 1.2 and 3.0 ng/ml confers an odds ratio of pregnancy of between 0.6 and 0.7.[23] On the other hand, progesterone elevation does not seem to confer a decreased chance of pregnancy in frozen–thawed cycles and cycles with egg donation.[23]
IVF using no drugs for ovarian hyperstimulation was the method for the conception of Louise Brown. This method can be successfully used when women want to avoid taking ovarian stimulating drugs with its associated side-effects. HFEA has estimated the live birth rate to be approximately 1.3% per IVF cycle using no hyperstimulation drugs for women aged between 40–42.[63]
Ovarian stimulation – You’ll take stimulation medications to increases both the quantity and quality of eggs. This usually begins during days 2-4 of your cycle and continues for around ten days. You’ll be closely monitored during this time to track your uterine lining, follicular development, and hormone levels. Once the follicles are optimal size, a trigger medication is given to fully mature the eggs.
This is less extensively studied. It is not yet known whether the ovarian stimulation and the insemination have independent beneficial effects or whether their beneficial effects are only seen when they are used in combination. Most likely they both independently increase fertility potential, with relatively more fertility benefit coming from the IUI component.
A recent large population-based study collected data from almost 5000 European patients. According to preliminary results presented at the 2019 European Society of Human Reproduction and Embryology, there is no benefit from ICSI in non-male factor cases. Importantly, the study reported no benefit of using ICSI regardless of how many eggs are retrieved after ovarian stimulation. Therefore, having a low oocyte yield should not be a reason for choosing ICSI over IVF.

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.


A closer look at the data suggest that the benefit of letrozole over clomid depended on the BMI of the participants. For patients with a BMI of less than 30 kg/m2, the cumulative live birth rate was approximately 30% for each group. However, for patients with a BMI over 30 kg/m2, twice as many patients had a live birth in the letrozole group than the clomid group.
3-6 months of treatment with Clomid pills (clomiphene citrate) might improve fertility by as much as 2 times as compared to no treatment. This is a very low level infertility treatment. Infertility specialists do not usually recommend Clomid treatment( without insemination) for unexplained infertility for women over the age of about 35. Most fertility specialists do not use it (without IUI) on any couples with unexplained infertility. If a woman is already having regular periods and ovulating one egg every month, giving Clomid, which will probably stimulate the ovaries to release 2 or 3 eggs per month (instead of one) is not really fixing anything that is broken - and is not likely to be successful. 
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