Do I need a trigger shot if I ovulate?

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Why do I need a trigger shot?
When should I take the trigger shot?
Do I inject trigger shots myself?
I have missed my trigger shot. What do I do?
Will the trigger injection be painful?
Potential trigger shot side effects

What is Ovulation Induction? Ovulation induction is a method of assisted reproduction which is appropriate for the treatment of fertility problems in women who do not have normal ovulation or have no ovulation at all because of hormonal disorders or because of Polycystic Ovary Syndrome.

Medications Used for Ovulation Induction

Your physician will determine the type of medication and dosage you will need. This is based on your age, your AMH level, your antral follicle count, and your underlying diagnosis.

Clomiphene citrate (Clomid)

Clomid is a pill that blocks estrogen receptors and stimulates production of more FSH (higher levels of FSH stimulate one or more follicles to develop). Side effects may include headache, hot flashes, bloating and mood swings.
To minimize the risks of multiple gestation, you will be monitored closely during your cycle; we do not recommend proceeding if you have more than four dominant follicles.
It is often used as first-line therapy in couples with unexplained infertility.

Letrozole (Femara)

Letrozole is a pill that temporarily reduces estrogen levels (this also stimulates production of more FSH). Side effects may include headache, hot flashes, bloating and mood swings.
To minimize the risks of multiple gestation, you will be monitored closely during your cycle; we do not recommend proceeding if you have more than four dominant follicles.
It is often used as first-line therapy in women with polycystic ovarian syndrome.

Injectable gonadotropins (Follistim/Gonal F/Menopur)

These are injectable hormones that contain either FSH alone or both FSH and LH to help promote follicle growth.
Injectable hormone use has a high rate of twins and triplets, so patients on these medications must be carefully monitored to minimize this risk.
To minimize the risks of multiple gestation, you will be monitored closely during your cycle; we do not recommend proceeding if you have more than four dominant follicles.

hCG (Ovidrel, Novaryl)

This is an injection that mimics the body’s LH surge, which causes the egg to mature and be released from the follicle.

Process: Clomid or LetrozoleWhile not everyone’s ovulation induction process will be the same, the general process one can expect is outlined below.

Step 1

Baseline testing is done to confirm that you are not pregnant prior to starting medications. This will be done on Day 2 to Day 5 of full flow of menses, and involves ultrasound and lab work. To schedule testing, inform your nursing team via the MyNM Patient Portal on Day 1 of your full-flow period. Baseline testing is done in the morning in order to get results the same day. These visits are meant to be quick because we realize that most of our patients work. If you have an urgent issue and must speak to a nurse during monitoring, please let the ultrasound tech know. Otherwise, you may leave after your bloodwork and ultrasound are complete. (Note: Please check with your office for scheduling and visit times.)

Step 2

If your baseline ultrasound is normal (no large cysts on the ovary) and your blood pregnancy test is negative, you will be instructed via the MyNM Patient Portal to start your medication.

Step 3

A mid-cycle ultrasound will be performed on approximately Day 13 of your cycle. The goal is to have one to three follicles that measure 16 mm or greater. Your uterine lining (endometrial thickness) should be greater than 6 mm.

Step 4

An hCG injection is given to trigger final egg maturation when the ovaries are ready. This can be easily self-administered on the evening after your monitoring scan. Freedom Pharmacy has an online tutorial that shows how to self-administer Ovidrel. If you have a male partner, you should have intercourse the night of your hCG injection.

Step 5

If intrauterine insemination (IUI) is part of your treatment course, you should schedule your IUI on the second morning after the hCG trigger shot. You should also plan to have intercourse the night of your IUI if possible. All partners must have an infectious disease screening prior to IUI, regardless of sex/gender.If IUI is not part of your treatment course, then have intercourse the night of your hCG injection and again 24 to 36 hours after your injection.

Step 6

A home pregnancy test can be taken 15 days after your hCG injection. If positive, please notify your nursing team through the MyNM Patient Portal. You will be asked to have a blood pregnancy test (bHCG) for confirmation and a second blood test 48 hours later.

Process: Injectable Gonadotropin

Here are the steps you can expect if you will be using injectable gonadotropin:

Step 1

Step 2

Expect to have an ultrasound and bloodwork done at your visits. Baseline testing and follicle scans are done in the morning in order to get results the same day. These visits are meant to be quick because we realize that many of our patients work. If you have an urgent issue and must speak to a nurse during monitoring, please let the ultrasound tech know. Otherwise, you may leave after your bloodwork and ultrasound are complete. (Note: Scheduling and visit times vary between sites. Please check with your office for details.)

Step 3

If your baseline ultrasound is normal (no large cysts on the ovary) and your blood pregnancy test is negative, you will be instructed to start your injections that evening.

Step 4

Injectable hormones should be administered every evening as instructed. Follistim, Gonal F and Ovidrel should all be kept refrigerated. You may experience some redness and burning at the injection site. Side effects include mood swings and bloating.

Step 5

You will be monitored every few days to ensure that you are developing the appropriate number of follicles. Some women are on injections for 5 days, and others require up to 14 days to produce mature-sized follicles. Each cycle for each patient is different. We recommend abstaining from sexual intercourse while on injectable hormones in case you develop too many follicles and we recommend cancellation. This minimizes the risk of becoming pregnant with twins and triplets.

Step 6

An hCG injection is taken to trigger final egg maturation when the follicles are of mature size. This can be easily self- administered on the evening after your monitoring scan. You should have intercourse the night of your hCG injection.

Step 7

If IUI is part of your treatment course, you should schedule your IUI approximately 36 hours after the hCG trigger shot. You should also plan to have intercourse the night of your IUI if possible. All partners must have an infectious disease screening prior to IUI, regardless of sex/gender.

Step 8

If you will not have IUI, then have intercourse the night of your hCG injection and again 24 to 36 hours after your hCG injection.

Step 9

A home pregnancy test can be taken 15 days after taking the hCG shot. If positive, please notify your nursing team through the MyNM Patient Portal. You will be asked to have a blood pregnancy test (bHCG) for confirmation and a second blood test 48 hours later.

We prefer to communicate test results to you via the MyNM Patient Portal, usually later the same day as your bloodwork is done. Please sign up and activate your account if you have not already done so.

The MyNM Patient Portal also allows you to email your care team at any time. It is used by both physicians and nursing teams during office hours (8 am to 5 pm, Monday through Friday). If you prefer to receive a phone call rather than a message via the MyNM Patient Portal, please notify the nursing team.

To Request an Appointment

Northwestern Medicine Fertility Center is now conveniently located in three locations: Chicago, Highland Park, and Oakbrook Terrace.

Visit our Locations & Appointments page for more information.

The trigger injection or ‘trigger shot’ as it is also known, is a hormonal injection used in fertility therapy. Brand names in the UK include Choragon, Ovitrelle, and Pregnyl, among others. A trigger shot usually contains a hormone called human chorionic gonadotropin, or HCG. It is hCG which triggers an ovary to mature and release an egg.

Why do I need a trigger shot?

Women undergoing IVF treatment do a trigger shot so that eggs are matured for collection. Once you have the injection, your ovaries are sent into a cycle of development which allows for egg collection at a specific time which will be outlined by your fertility team.

When should I take the trigger shot?

You will be given careful guidance on this topic by your Apricity advisor. It is important to follow the timing instructions exactly as delays of just a few hours can cause issues with your treatment cycle. Essentially, in most cases the trigger shot needs to be taken 36 hours before egg collection, or a day and a half prior. So if you have a midday appointment for egg collection on Tuesday, you would take the trigger shot at midnight on the Sunday prior. There are some variations to this time window and your advisor will inform you if your case is one of those.

The trigger shot timing is in line with the development of your follicles, which your clinical team will have been tracking. The trigger shot tends to be done when a good number of follicles have grown to their optimal size. Under or overdeveloped eggs have a lower chance of conception success.

Do I inject trigger shots myself?

Generally yes, especially as the 36 hour window from injection to collection often means the shot is usually taken in the evening and sometimes late in the evening. We ensure that an Apricity advisor is available at the time of the injection in case you have any last minute questions.

I have missed my trigger shot. What do I do?

If you are late taking your trigger shot, it is imperative you let your Apricity advisor or clinic know as soon as possible, as there may be things that they can do to try and salvage the situation. It is not possible to retrieve an egg after the ovary has released it, so it’s important to try and resolve this as soon as possible. In certain circumstances, it may be feasible to adjust your egg collection time.

Will the trigger injection be painful?

There are in fact two ways of administering the trigger injection. It can either be given into the muscle (intramuscular) or under the skin (subcutaneous), which is the most common route. An intramuscular injection will feel the same as getting a vaccine shot at your GP and can cause more bruising than when injecting under the skin.

Women occasionally report that subcutaneous injections cause the site to become red, inflamed and itchy for a day or two. Either way, the side effects immediately post injection are usually minimal.

Potential trigger shot side effects

Most women do not experience any side effects following the trigger injection, apart from perhaps some local irritation at the injection site, which is usually transient. At this stage of your treatment, it is not uncommon to have been already experiencing some abdominal discomfort or mild bloating due to the combined effect of the treatment hormones and the increase in the size of the ovaries. Following the trigger injection, these symptoms can sometimes increase. As this is not intended to be an exhaustive list of side effects, do not hesitate to seek advice if you are concerned about any new symptoms.

Make sure to monitor any abdominal discomfort or bloating as this can sometimes be associated with Ovarian Hyperstimulation Syndrome. Contact your Apricity advisor if you have any concerns.

If you’re interested in getting started with Apricity, use the link below to book a free call with a fertility advisor at a time that suits you.

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