Furthermore, the twin risk was not significantly elevated in any of the three groups. The key difference between these studies is that the dose of gonadotropins was higher in the AMIGOS study units than the Huang study 75 units. A higher dose often means more eggs ovulated and a greater risk of twins or more.
This is important because clomid and letrozole are also cheaper to purchase hundreds vs. For this reason, many clinics have moved away from using gonadotropins in IUI cycles.
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.
IUI can be a successful treatment strategy for patients with mild not severe male factor infertility but its rate of success is dramatically lower than what is achieved with IVF for this group.
TMC is an equation combining 3 parameters from the semen analysis : volume, concentration, and motility. The data we have available is conflicting.
A much larger study from Shady Grove, performed on over 46, patients reveals far higher rates of success with three additional observations:. IUI pregnancies are indeed possible using sperm with TMCs below 9 million and in this study, as low as , Below 9 million TMC, the rate of decline for success is shallow , calling into question the wisdom of arbitrary TMC cutoffs study authors: "a specific cutoff threshold should not be utilized as an absolute contraindication for performing IUI For a number of reasons e.
As we've mentioned, IUI rates of success also vary dramatically by the age of the patient receiving the insemination, which drugs accompany the insemination, follicle count and more. Unfortunately, a person cannot look at the TMC from a semen analysis and know precisely where they fit into this rubrik. This will tell them how drastically the wash impacts their TMCs. Given the correlation between TMC when it's below 9 million and IUI success rates, one plausible option is to "pool" successive ejaculates which can nearly triple the TMC available for people who produce few sperm per ejaculate.
Here we address two types of patients: those unable to have a period called anovulatory and those with irregular periods. Amongst both groups those with no period or irregular periods there are three types of patients: those with hypothalamic dysfunction , those with PCOS , and those with no diagnosis but who have had hypothalamic dysfunction ruled out. Patients with hypothalamic dysfunction are not producing signals within their brains to tell the ovary to mature an egg.
Neither clomid nor letrozole will help them. For these patients, IUI must be accompanied by gonadotropin to be effective. Next we have patients who have either PCOS or no diagnosis.
The best study in the field enrolled women to receive clomid or letrozole, followed them for 5 courses of therapy and revealed that the group receiving letrozole had higher live birth rates and fewer multiple gestations.
A closer look at the data suggest that the benefit of letrozole over clomid depended on the BMI of the participants. Investigators concluded there was no statistically significant difference. One might conclude there is thus no benefit to adding an IUI to a clomid cycle. However, the applicability of this study to all patients may be limited because it excludes women with a BMI over 30 common for women with PCOS and used outdated sperm washing techniques.
IUI preferably with letrozole instead of clomid is probably a good option for women with PCOS or irregular cycles in the event that:. There are multiple strategies for causing ovulation in clomid or letrozole resistant patients. Some of these include adding medications such as dexamethasone or metformin to the treatment regimen. Another approach is changing to gonadotropin injections. Rather than tricking the brain into sending a stronger signal to the ovaries to cause follicle recruitment, gonadotropins directly stimulate the ovary to recruit multiple follicles.
The available data on how effective a gonadotropin-plus-IUI strategy is in patients with irregular, or non-existent, cycles is limited and unfortunately includes other drugs. However, these studies give us a sense for how well a patient can expect to do if she has irregular, or non-existent, cycles and is using a gonadotropin-plus-IUI approach.
The bad news is that gonadotropins produce a high multiple pregnancy rate, especially in this population. In the Palomba study, the IUI-plus-gonadotropin arm recorded over a third of pregnancies were multiple birth. Reproduction , right? But then, somewhere along the way, the fertilized egg divides into two, resulting in identical twins. The chances of having identical twins is relatively rare — around 3 or 4 in every 1, births.
And while it may be obvious, identical twins are always the same sex, either both boys or both girls, at birth. Fraternal twins, on the other hand, result when two separate eggs are fertilized by two separate sperm cells.
Both fertilized eggs implant into the uterus and — 9 months later — two babies are born. Fraternal twins can either be two boys, two girls, or a boy and girl. They may or may not look a lot alike. One reason for this may be hyperovulation, which is a situation where the body releases two or more eggs during ovulation — basically a requirement for having fraternal twins. Are you over age 35?
Hormonal changes that happen as you near menopause may encourage the body release more than one egg during ovulation. If two or more are fertilized and both implant, you might just need two cribs in your nursery. Taller women seem to have a higher rate of having twins. This may sound a bit strange, but researchers credit a certain insulin-like growth factor with this possibility. Women who have overweight or obesity also have a higher chance of conceiving twins naturally.
Specifically, the chances are highest if your body mass index BMI is above 30, according to a study that looked at data from more than 51, births in the United States. A later study in that analyzed maternal characteristics among women in Norway said rates of twins increased among women with BMI above Having a BMI over 30 may also place you in the high-risk category of pregnancy, so talk to your doctor about a healthy weight for you before getting pregnant.
Black women deliver twins at a higher rate than white women, according to birth statistics in the United States. But Asian and Hispanic women deliver twins at a lower rate than the other groups. This may occur because women who eat dairy may be taking in extra insulin growth factor. The cows release this hormone into their milk and — when consumed — it may influence human reproduction.
And little research if any regarding dairy intake affecting twin birth rate has been completed since. He or she may be the reason you end up having twins.
A previous pregnancy — or, better yet, previous multiple pregnancies — may increase your chances of having twins. In fact, according to the , women between the ages of 35 to 40 with four or more children are three times more likely to have twins than a woman under 20 without children.
Clomiphene citrate Clomid and letrozole Femara are ovulation-stimulating medications. Both of these drugs are often given in IUI cycles and may help the body produce multiple eggs that may release at the same time.
If two or more are fertilized and implant, twins are a possibility. This decreases the risk of multiples while increasing the chance of a successful implantation with a healthy embryo. According to Dr. That said, Dr. Kort describes the times when your doctor might recommend transferring more than one embryo:.
This is because babies born early, a. According to the March of Dimes, certain fertility treatments may also increase your risk of having a low birth weight baby or one with birth defects. All of that said, many preemies do completely fine, and an early delivery is not a guarantee that your babies could have health problems.
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