How Long After Trigger Shot Is IUI Done (And Why)?

Exact Answer:  After 24-36 hours

IUI termed Intrauterine insemination is considered as a very simple and safe therapy due to its capability of reducing serious complications. But this treatment includes few careful steps which are to be done before actual procedures. In most cases, IUI does not require any additional medications or supplements to get rid of pain and takes very few minutes to complete it.

To speed up the procedure or to get extra benefits out of it, trigger shot is often used with therapies like IUI and IVF.  If the shot is required, your respective specialist will make you aware of it in addition to the IUI procedure and medications.

How Long After Trigger Shot Is IUI Done

How Long After The Trigger shot is IUI Done?

When a woman grows a follicle and proceeds with the procedures naturally without any drugs, she ovulates naturally and it is referred to as the natural IUI cycle. The trigger shot is an injectable medication also known as Ovidrel which is used along with other techniques or by itself.  It depends on factors size of the follicle and your endometrium. 

To cope up with the ovulation and without affecting the pregnancy, IUI is recommended and most specialists prefer to perform after 24 to 36 hours of trigger shot. During the time of ovulation, follicle size should be nearly 18 to 20mms. The measurements may vary depending on the physicians. You will be treated with a trigger shot when the follicle reaches 15 mm and when the uterine lining is 7 to 8mms thick. 

The time may also vary depending on the number of IUI done, if one IUI is done, a trigger shot is given, and IUI is performed after 36 hours, and if more than one IUI is done, IUI is performed after 24 or 48 hours after the trigger shot. To help with the implantation, few doctors advise taking supplements of progesterone may be by orally or vaginally. 

Though there are numerous advantages of trigger shots, you may experience various side effects like the stomach or pelvic pain, nausea, and bloating. The pregnancy test should be taken at least after 2 weeks of trigger shot to get worthy results as it takes nearly 12 to 14 days to remove from your system. Because, trigger shot contains HCG, which may tend to show positive results without being pregnant in case of testing before 14 days. 

In summary,

Number of IUIsFollicle sizeTime after shot
115mm36 hours
More than 115mm -20 mm24-48 hours

Why Does It Take That Long for IUI After Trigger Shot?

The trigger shot is preferred when IUI should be done even more precisely. Rather than waiting to release eggs naturally, this shot with the help of injected hormone stimulates to release of mature eggs to prepare for IUI. The IUI treatment is scheduled between 24 to 36 hours of the post-trigger shot.

This shot triggers the body to release eggs as it contains HCG to the tune of 5,000 or 10,000 IUs. In few cases, time doesn’t matter for IUI therapy after the shot, but the sperm should be available, reasonably close during and preceding ovulation. Since the time of ovulation is unknown, it can take a minimum of 12 hours to reach out to an egg and enter the fallopian tube. Generally, the follicle grows nearly up to 2mms each day but this relies on the individual.

This is the reason when ultrasound is recommended when you get closer. The journey of fertilization to implantation could take nearly 5 to 9 days and in rare cases, it extends up to 12 days. Normally, the success rate of trigger shot alone is very less, but when combined with other procedures like IUI or IVF it proves to be beneficial.

Similarly, the rate of pregnancy with only IUI treatment would be 6% whereas when combined with trigger short, the success rate could be around 18 to 20 percent. According to the study, when the trigger shot was done concerning a woman’s natural LH surge, the pregnancy rate was above 25 percent.


You might feel little tenderness, discomfort, and pain at the injection site which will subside naturally. Before proceeding for a trigger shot along with IUI, list out its benefits and effects. It would be worth doing only during timed intercourse like IUI or IVF. But the success rate also depends on age, type of infertility, and few other conditions too.

Things like tracking the size of the follicle and uterus lining are mandatory to undergo a trigger shot. Even though when you prefer IVF with follicle size 15 to 20mms, the timing would be the same as for IUI.


One request?

I’ve put so much effort writing this blog post to provide value to you. It’ll be very helpful for me, if you consider sharing it on social media or with your friends/family. SHARING IS ♥️