Your Day-by-Day Embryo Development
Key Concepts:

Day 0

The day of your egg retrieval.

Day 1

 No updates on these days. Embryo is left in incubator, undisturbed.

Day 2 – Day 3 – Day 4

On day 2, the embryos should start showing 2-4 cells, followed by 6-8 cells on day 3, and more than 10 cells, Morula or Compaction of the cells on day 4. During these days, the Embryology Team does not check your embryo culture to avoid disturbing the culture. Therefore, you will not receive any updates.

Day 5 – Day 6 – Day 7

The embryo can potentially reach the blastocyst stage between day 5 to day 7.

You will receive updates from our IVF Lab Team each one of these days.

Key Concepts

Oocyte – Egg

Female gamete cells provided by the ovary.

Sperm

Reproductive cell produced by males.

MII Egg

Mature egg. These oocytes are ready to perform ICSI or Vitrification.

2PN

Terminology used to describe that the egg is showing normal fertilization.

Blastocyst

Early stage of embryonic development, characterized by a hollow ball of cells with an inner cell mass that will give rise to the embryo.

Blastocyst Biopsy or TE Biopsy

TE biopsy refers to trophectoderm biopsy, a procedure where a small number of cells are removed from the outer layer of the developing blastocyst for genetic analysis. The IVF Lab Team will perform the biopsy and then cryopreserve the blastocyst.

PGT-A

PGT-A can give information about the chromosomal genetic health of your embryo to help the care team to select an embryo for transfer, helping to improve your chances of achieving a successful pregnancy.

Chromosomes are structures made of protein and DNA that carry genetic information from the sperm and egg to the embryo. A chromosomally normal, or euploid, embryo contains 23 pairs of chromosomes amounting to 46 in total. One pair of chromosomes comes from the egg and the other the sperm. When an embryo doesn’t have the correct number of chromosomes it is called aneuploid. A euploid embryo is much more likely to result in successful implantation and the birth of a baby.

PGT-SR

PGT-SR is appropriate for people who have a chromosome rearrangement, and thus are at risk of creating embryos with the incorrect chromosome number or structure. You may consider PGT-SR for chromosome rearrangements if you had a child or pregnancy with a chromosome rearrangement or if you or your partner are a carrier of an:

  • Inversion
  • Reciprocal translocation
  • Robertsonian translocation

PGT-M

For people who know they are at increased risk of passing on a specific genetic condition, PGT-M, can be performed prior to embryo transfer to greatly reduce the risk of having a child affected with that condition.

PGT-M tests are created uniquely for each family. It can be performed for nearly any single gene disorder as long as the specific familial mutation has been identified and appropriate family members are available for test preparation.

What is a Reproductive Endocrinologist?

The endocrine system orchestrates a complex symphony of hormones that regulate various bodily functions, playing a pivotal role in maintaining hormonal equilibrium. Within the realm of reproduction, hormones like estrogen (in females) foster egg maturation, while testosterone (in males) fuels sperm production. A board-certified reproductive endocrinologist, often referred to as a fertility specialist, is a medical professional who undergoes advanced training in obstetrics and gynecology, followed by specialized training in reproductive endocrinology and infertility.

Specialists primarily

These specialists primarily focus on addressing hormonal and reproductive endocrine disorders in both males and females. Their expertise encompasses various fertility-related conditions such as polycystic ovary syndrome (PCOS), menstrual irregularities, menopause related concerns, cancer and fertility (oncofertility), diminished ovarian reserve (involving both low egg quantity and quality), recurrent pregnancy loss, and much more.

Education and Training:

Reproductive endocrinologists have a robust educational and training background, which includes:A four-year undergraduate degree in a science-based field,such as biology, chemistry, or pre-med. Four years of medical school leading to a Doctor of Medicine (MD) or Doctor of Osteopathic Medicine (DO) degree.A four-year residency program specializing in Obstetrics and Gynecology.A fellowship in Reproductive Endocrinology and Infertility, which follows the completion of the obstetrics and gynecology residency.Board certification in Reproductive Endocrinology and Infertility.Subspecialty training in areas such as assisted reproductive technology, male infertility, third-party reproduction, and other relevant specialties.Apart from physicians, there are also mid-level providers, such as nurse practitioners and physician associates, who practice in the field of fertility care.

Why Consult a Reproductive Endocrinology Specialist?

Reproductive endocrinologists offer a comprehensive range of fertility care services, treatments, and diagnostic procedures. These include:

Fertility Evaluations: Thorough assessments of an individual or couple’s reproductive health to identify underlying issues affecting fertility.

Ovulation Induction: Stimulating the ovaries to produce multiple eggs, enhancing the chances of fertilization through medications like clomiphene citrate.

Intrauterine Insemination (IUI): Deposition of sperm directly into the uterus during ovulation to increase the likelihood of fertilization.

In Vitro Fertilization (IVF): Retrieval of eggs from the ovaries, fertilization outside the body, and transferring resulting embryos into the uterus.

Preimplantation Genetic Testing (PGT): Screening embryos for genetic and chromosomal abnormalities before implantation.

Fertility Preservation: Cryopreservation and freezing of genetic materials, including eggs, sperm, and embryos.

Oncofertility:  Fertility preservation for individuals facing cancer treatments (e.g., chemotherapy, radiation) that may impact their reproductive capabilities.

Third-Party Reproduction: Fertility care involving donated genetic materials (eggs, sperm, or embryos) or gestational surrogacy.

LGBTQ+ Family Building: Specialized services to assist LGBTQ+ individuals and couples in building their families.

Fertility Evaluation Procedures: Reproductive endocrinologists possess the expertise to conduct comprehensive evaluations aimed at identifying the root causes of infertility in individuals and couples. Common diagnostic procedures include:

Hormonal Testing: Assessing levels of reproductive hormones like follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, and testosterone.

Ovarian Reserve Testing: Evaluating the quantity of a person’s eggs through blood and ultrasound imaging tests.

Hysterosalpingography (HSG): An imaging test to assess the fallopian tubes and uterine cavity for abnormalities or blockages.

Laparoscopy: A minimally invasive surgical procedure to examine the pelvic organs for abnormalities or endometriosis.

Our Reproductive Endocrinologists:
Reproductive endocrinology specialists play a pivotal role in helping individuals and couples overcome reproductive challenges while optimizing fertility to achieve their family planning goals. It’s essential to note that specific services, treatments, and subspecialties may vary among different fertility clinics and individual practitioners.

If you’re ready to take the next step on your fertility journey, we encourage you to reach out to Main Line Fertility and schedule a consultation with one of our esteemed reproductive endocrinologists.

Educational FAQs

What is infertility?
Infertility is a common issue that affects around 15-20% of couples. In women under the age of 35, there’s a 20% chance of conceiving during each menstrual cycle. This means that 50% of couples trying to conceive will become pregnant within 3 months and 85% within a year. For women over the age of 35, these percentages are lower. Infertility is typically defined as the inability to conceive after one year of unprotected intercourse for women under 35 and after six months for women over 35.
The main causes of infertility include male factors, tubal or pelvic issues, ovulation problems,unexplained infertility, and other factors. Sometimes, unexplained infertility can be due to undiagnosed issues related to egg quality or immunologic issues affecting embryo implantation. Treatment varies depending on the cause, ranging from basic treatments like medication to induce ovulation to more advanced options like in vitro fertilization (IVF) or reproductive surgery.
The most commonly used test for diagnosing tubal blockage is a hysterosalpingogram (HSG) or dye test, where a dye is injected through the cervix, and x-rays show if the dye spills into the pelvis. Tubal damage is often caused by previous pelvic infections, such as Chlamydia, as well as other factors like endometriosis or abdominal surgery. Laparoscopy is the preferred method for both diagnosing and treating tubal disease.
Sperm analysis is used to assess sperm parameters, including volume, count, motility, and morphology. A normal sample should have specific values for each parameter. Abnormalities can affect fertilization chances, and severe abnormalities may require IVF and intracytoplasmic sperm injection (ICSI). To assess sperm quality, a sperm DNA fragmentation test can be performed to evaluate DNA breaks and immaturity, which can affect fertility potential.
Ovulation issues contribute to about 10-15% of infertility cases. Regular menstrual bleeding accompanied by certain symptoms, like cramping and breast tenderness, is a reliable indicator of ovulation. Hormone tests and monitoring basal body temperature can also help confirm ovulation. Irregular menstrual cycles may be a sign of ovulatory problems, which can be caused by various factors, including thyroid dysfunction or hormonal imbalances.
The timing of ovulation is crucial for conception. Ovulation typically occurs 13-14 days before the onset of menstruation. Charting basal body temperature can help pinpoint ovulation, but it’s not ideal for timing intercourse. Ovulation predictor kits are a practical option to predict ovulation, as they detect the LH surge that triggers ovulation.
Fertility potential decreases with age, and ovarian reserve decreases as well. The number of eggs in the ovaries can be assessed by measuring hormones like follicle-stimulating hormone (FSH) and Anti-Mullerian hormone (AMH). Elevated FSH or estradiol levels may indicate decreased ovarian reserve. A high FSH level can diminish the chances of conception, and very high FSH levels may necessitate donor eggs for treatment.
PCOS is a complex endocrine disorder characterized by irregular or absent ovulation,polycystic-appearing ovaries on ultrasound, and hormonal imbalances. It can lead to infertility and other health issues like insulin resistance and an increased risk of diabetes. Treatment typically involves fertility medications to induce ovulation, with options like clomiphene citrate (Clomid) or injectable gonadotropins, depending on the patient’s response.
A luteal phase defect (LPD) occurs when the second half of the menstrual cycle, the luteal phase, is shorter than the normal 14 days. LPD can be diagnosed through endometrial biopsy or hormonal assessments, and treatment may involve medications like clomiphene citrate,progesterone supplementation, or HCG injections. LPD is a potential factor in infertility, as it can affect the uterus’s readiness for implantation.
Cervical mucus plays a crucial role in fertility. It typically prevents bacteria from entering the uterus and facilitates the passage of sperm during ovulation. Abnormal cervical mucus can prevent sperm from reaching the egg, and in some cases, women can develop antibodies against their partner’s sperm. These issues can be diagnosed through a post-coital test and may require intrauterine insemination (IUI) or IVF for treatment.
The post-coital test (PCT) evaluates the interaction between sperm and cervical mucus. It’s performed by examining a sample of cervical mucus 6-18 hours after intercourse to assess the presence of motile sperm. A poor PCT may indicate issues like anti-sperm antibodies. IUI is recommended for the treatment of repeated poor PCT results.
The treatment of male factor infertility has made significant progress with the advent of assisted reproduction techniques. Depending on the severity of the issue, treatment can range from simple techniques like sperm washing to more advanced options such as intracytoplasmic sperm injection (ICSI). ICSI is particularly effective for severe cases of male factor infertility and can help achieve fertilization.
Intrauterine insemination (IUI) is a procedure in which a concentrated sample of motile sperm is injected into the uterus through a thin catheter at the time of ovulation. This treatment is used for cases of cervical issues, unexplained infertility, and mild male factor infertility. Proper timing of IUI is crucial, which can be achieved using ovulation predictor kits or HCG injections to trigger ovulation..
Clomiphene citrate (Clomid) is a fertility medication that stimulates the production of follicle-stimulating hormone (FSH) and can help induce ovulation. It is commonly used to treat women who do not ovulate. Clomid can also be used for ovulating women to increase the chances of conceiving, although its success rates are typically around 5-8% per cycle.
IVF is a procedure where the ovaries are stimulated with fertility medications to produce multiple mature eggs. These eggs are then retrieved, fertilized in a laboratory with sperm, and the resulting embryos are transferred back into the uterus.
ICSI is a procedure that allows the treatment of the most severe male factor infertility cases. Using ultra-fine instruments, it is possible to select a single sperm and inject it into the egg to accomplish fertilization without damaging the egg. Before ICSI, there was no effective treatment for poor sperm other than using donor sperm. In the era of ICSI, male factor infertility cases have high success rates with IVF.
Endometriosis is a condition where the lining of the uterus, known as the endometrium, is found in other areas of the body. These displaced endometrial tissues can cause pain, inflammation,and sometimes lead to fertility issues. The exact cause of endometriosis is not known, but it’s thought to be related to retrograde menstruation where menstrual tissue flows backward into the pelvic area. Endometriosis can be progressive and is stimulated by the hormone estrogen.
Symptoms of endometriosis can vary but often include cyclic pelvic pain, which may start before menstruation and last more than 48 hours. Pain during intercourse, bowel movements, or urination is also common. It’s important to note that the severity of symptoms doesn’t always correlate with the stage of the disease.

The symptoms of cyclic pain may suggest endometriosis, but they are not specific to the condition, as many women experience pain during their menstrual cycle. An ultrasound can identify large ovarian cysts known as endometriomas, indicative of advanced disease, but it cannot detect early stages of endometriosis. The only definitive way to diagnose endometriosis is through laparoscopy, a surgical procedure where the surgeon visualizes and treats the disease.

Endometriosis can affect fertility in several ways. In early stages, it can impact the immune system. In advanced stages, there’s a mechanical blockade and a decrease in egg reserve. In severe cases, pelvic adhesions and scarring can block the fallopian tubes, preventing eggs from reaching sperm and the uterus. Endometriomas can compromise the quality and quantity of eggs. Even mild endometriosis can negatively affect fertility by creating an abnormal immune response in the endometrium that may prevent implantation.
The treatment of endometriosis is necessary if you are experiencing significant pain or if you are seeking to improve fertility. If pain is your primary concern, treatment is essential, regardless of the stage of the disease. When fertility is the main concern, surgical intervention should be considered as it can improve the chances of conception by restoring the integrity of the fallopian tubes and reducing inflammation.
Laparoscopy is a surgical procedure that involves the insertion of a thin, telescope-like instrument into the abdominal cavity through a small incision near the belly button. This instrument, called a laparoscope, allows the surgeon to visualize and access the abdominal and pelvic organs, including the uterus, fallopian tubes, ovaries, bowel, liver, and gallbladder. Additional small incisions are made in the lower abdomen to manipulate pelvic organs.Laparoscopy is used to diagnose and treat various gynecologic and infertility issues, and it offers a quicker recovery time compared to open abdominal surgery.
Hysteroscopy is a minimally invasive outpatient procedure that involves the insertion of a small telescope-like instrument into the uterine cavity through the vaginal canal. This instrument allows for the visualization and treatment of conditions within the uterus, such as polyps, scar tissue, or fibroids. Different fluids may be used to distend the uterine cavity during the procedure. Hysteroscopy can be performed with minimal anesthesia and generally has a quick recovery time. It is useful for diagnosing and treating uterine abnormalities.
A sonohysterogram, also known as fluid ultrasound or hydrosonography, is a diagnostic procedure used to image the uterine cavity. It is performed in the office without anesthesia. A thin catheter is inserted through the cervix into the uterus, and saline (salt water) is injected into the uterine cavity while transvaginal ultrasound is conducted. The fluid distends the uterus, allowing for the detection of conditions like polyps, adhesions, or small lesions that might be missed on other tests. The procedure may cause some cramping, but it is usually well-tolerated.
Tubal damage can result from previous infections, endometriosis, or pelvic surgery. While most types of tubal damage do not require surgical intervention to improve IVF outcomes, there is an exception: hydrosalpinx. Hydrosalpinx refers to blocked fallopian tubes that become filled with fluid, which can have a toxic effect on embryos. This fluid can also block the uterus, affecting implantation. In cases of hydrosalpinx, the tubes are typically removed or ligated before undergoing IVF to optimize the chances of success.
Tubal reversal is an option for women who have undergone tubal ligation and want to restore their fertility. The procedure can often successfully reconnect the fallopian tubes. Following surgery, the tubes are open 70-80% of the time, and women have a 50-60% chance of conception during their reproductive lifetime. Tubal reversal is a suitable choice for younger women who desire more than one child after reversing the ligation. However, if you have had a tubal ligation and seek fertility assistance, IVF is also a viable option, with success rates up to 50-80%. In cases of tubal ligation, IVF can provide effective pregnancy rates, especially since these individuals were using contraception and may not have infertility issues.
At Empower Fertility, in vitro fertilization (IVF) is recommended for various indications, ensuring personalized care for those seeking fertility solutions. These indications include: Decreased Ovarian Reserve: IVF can be an effective option for individuals with a diminished ovarian reserve, where the number and quality of eggs are reduced. This is particularly crucial,as the availability of viable eggs significantly influences the chances of success. Blocked Fallopian Tubes: IVF is a valuable choice for individuals with blocked fallopian tubes,as it circumvents the need for open tubes, allowing for successful fertilization within the controlled environment of the laboratory. Moderate or Severe Male Factor Infertility: When male infertility is a factor, IVF offers a solution by facilitating the direct injection of sperm into the egg through Intracytoplasmic Sperm Injection (ICSI), ensuring fertilization. Unexplained Infertility: In cases where the cause of infertility remains unknown, IVF is a versatile approach. It allows for controlled conditions, eliminating potential obstacles to conception. Endometriosis: Empower Fertility recognizes endometriosis as a common cause of infertility. In advanced cases of endometriosis, IVF is often a recommended treatment option. While women with mild endometriosis may also benefit from IVF, those with advanced stages may experience even higher success rates with this approach. Maternal Age > 40: Maternal age, particularly when exceeding 40, is a relative indication for IVF. This is due to the rapid decline in ovarian reserve and egg quality associated with advancing age. IVF can provide a targeted and effective means of addressing these challenges.Polycystic Ovary Syndrome (PCOS): Women with PCOS, a condition causing irregular ovulation or anovulation, can choose IVF at Empower Fertility. This option minimizes the risk of high-order multiple pregnancies (triplets or higher) because the number of embryos implanted can be carefully controlled during IVF compared to other treatments like Intrauterine Insemination (IUI). At Empower Fertility, our approach to IVF is tailored to the specific needs and circumstances of each individual, offering hope and comprehensive solutions for diverse fertility challenges. Please consult our team to discuss your unique situation and explore the best path forward for your journey to parenthood.