IVF, or in vitro fertilization, is a multi-step process that typically spans four to six weeks from start to finish. It involves stimulating the ovaries to produce multiple eggs, retrieving those eggs surgically, fertilizing them in a lab, and then transferring a resulting embryo into the uterus. The full process also includes preparatory steps, monitoring appointments, and hormonal support afterward. Here’s what each phase actually looks like.
Preparation and Priming
Before the active treatment begins, many clinics prescribe a short priming phase lasting one to three weeks. This might involve birth control pills or estrogen patches to synchronize your cycle and give your care team control over timing. Not everyone needs priming, but it’s common.
A few days after your period starts, you’ll go in for a baseline vaginal ultrasound and blood tests. These confirm that your ovaries are at a resting state and ready to respond to stimulation medications. If everything looks good, injections begin.
Ovarian Stimulation
The stimulation phase is the most intensive part of IVF for most people. You’ll give yourself daily injections of follicle-stimulating hormone (FSH) for roughly 10 to 14 days. The goal is to push your ovaries to mature multiple eggs at once, rather than the single egg your body normally releases each month.
Before stimulation starts, you may also take a “down-regulation” medication. This temporarily shuts down your ovaries’ natural signaling so they don’t release eggs prematurely and so they respond more predictably to the FSH injections. During this phase, you’ll visit the clinic every two to three days for ultrasounds and blood draws, typically four to six short visits of about 15 to 20 minutes each. Your team uses these to track how many follicles are growing and how large they are.
When follicles reach the right size, you’ll take a “trigger shot” that finalizes egg maturation. Egg retrieval is scheduled 36 to 37 hours later, timed precisely before your body would ovulate on its own.
Egg Retrieval
Egg retrieval is a minor surgical procedure that takes about 10 to 20 minutes. You’ll receive intravenous sedation, so you’re asleep for the entire process. A thin needle guided by ultrasound passes through the vaginal wall to reach each ovary, and fluid is drawn from the follicles to collect the eggs.
Afterward, you’ll rest in a recovery area for about an hour. Most people feel crampy and bloated for the rest of the day. Your clinic will typically advise you to take the day off and avoid strenuous activity, but most people return to normal routines within a day or two.
Fertilization in the Lab
Once eggs are collected, fertilization happens one of two ways. In conventional IVF, eggs and sperm are placed together in a dish and sperm penetrate the eggs on their own, similar to how fertilization works naturally. In the alternative method, called ICSI, an embryologist selects a single sperm and injects it directly into each egg using a microscopic glass needle.
About 60% of IVF procedures today use ICSI. It’s typically recommended when sperm count or motility is low, when frozen eggs or sperm are being used, when the egg provider is over 35, or when a previous IVF cycle failed to produce fertilized eggs with the conventional approach. Fertilization rates with ICSI range from 50% to 80%.
Embryo Development
Fertilized eggs are placed in an incubator and monitored over the next five to six days. By day five or six, a healthy embryo reaches what’s called the blastocyst stage, containing more than 100 cells that have already begun to differentiate. At this point, distinct cell groups are visible: one cluster that will become the placenta and another that will become the fetus.
Not all fertilized eggs make it to this stage. It’s common for the number to drop significantly between fertilization and day five. The embryos that do survive to blastocyst are considered stronger candidates for transfer or freezing.
Optional Genetic Testing
Before transfer, you may have the option to test embryos genetically. The two main types serve different purposes. One screens all chromosomes for missing or extra copies, which is the most common cause of miscarriage and failed implantation. The other targets a specific known genetic condition, such as cystic fibrosis or sickle cell disease, when one or both parents are carriers.
Testing for specific inherited conditions has a well-established track record. Chromosome screening is more debated. Some smaller studies found higher pregnancy rates in younger patients, but the American College of Obstetricians and Gynecologists notes that its overall benefit is still being evaluated, and not every patient will see improved outcomes from it. If testing is done, results typically take one to two weeks, meaning the embryo will be frozen and transferred in a later cycle.
Fresh vs. Frozen Embryo Transfer
Embryos can be transferred in the same cycle they were created (a fresh transfer) or frozen and transferred in a subsequent cycle. The right approach depends on several factors, including your age, your hormone levels after retrieval, and whether genetic testing was done.
For people under 35, fresh and frozen transfers produce similar live birth rates, with fresh transfers having a slight edge (about 47% vs. 44%). But this shifts dramatically with age. For those 38 to 40, frozen transfers lead to live births about 36% of the time compared to 28% for fresh. By ages 41 to 42, the gap widens to 30% versus 16%. The likely reason: freezing allows the uterine lining to recover from the hormonal intensity of stimulation, creating a more receptive environment for implantation. For people over 38, many clinics now recommend freezing all embryos and transferring in a later cycle.
The Embryo Transfer
Transfer itself is one of the simplest steps. It takes only a few minutes and usually requires no anesthesia. A thin catheter is guided through the cervix, and the embryo is placed in the uterus under ultrasound guidance. Most clinics transfer a single embryo to reduce the risk of twins or higher-order multiples.
If you’re doing a frozen transfer, you’ll take estrogen and progesterone in the weeks leading up to it to prepare your uterine lining. These hormones continue after transfer and, if pregnancy occurs, typically last until 10 to 12 weeks of pregnancy, when the placenta takes over hormone production.
The Two-Week Wait and Pregnancy Test
After transfer, there’s roughly a two-week waiting period before a blood test can reliably detect pregnancy. This is often described as the most emotionally difficult part of the process. There’s nothing specific you need to do during this time other than continue any prescribed medications. A blood test at the clinic measures pregnancy hormone levels and gives a definitive result.
Side Effects and Risks
The most common side effects during stimulation are bloating, mood swings, headaches, and soreness at injection sites. After retrieval, cramping and bloating are normal for a day or two.
The most significant risk is ovarian hyperstimulation syndrome (OHSS), where the ovaries swell and leak fluid into the abdomen. Mild cases cause abdominal pain, bloating, nausea, and tenderness near the ovaries. These symptoms are uncomfortable but usually resolve on their own. Severe OHSS is less common but requires medical attention. Warning signs include rapid weight gain (more than about two pounds in 24 hours), severe and persistent vomiting, shortness of breath, decreased urination, and a noticeably tight or enlarged abdomen.
What It Costs
In the United States, a single IVF cycle typically costs between $12,000 and $18,000. That price usually covers monitoring, egg retrieval, fertilization, and embryo transfer. Medications are almost always billed separately and add $3,000 to $5,000 on top of the base cost. Optional services like genetic testing, embryo freezing, and frozen storage fees push the total higher. Many people go through more than one cycle, so the cumulative cost can be substantial. Insurance coverage varies widely by state and employer, so it’s worth checking your specific plan before starting.