This study will recruit patients from the NJ/NY/CT/eastern PA area only.

Twin and higher-order multiple pregnancies are the most common and most significant complication of pregnancies conceived through assisted reproductive technologies (ART). Twin rates in in vitro fertilization (IVF) cycles are approximately 30%. These pregnancies have increased complications for both the mother and the babies. A singleton, one baby, is the safest outcome for an IVF cycle. The surest way to reduce the risk of multiple births in IVF cycles is to transfer fewer embryos. Prior studies on single embryo transfer (SET) have shown decreased pregnancy rates because of the difficulty in selecting which embryo to transfer. Being chromosomally normal is necessary for the delivery of a healthy baby. The investigators are now able to screen all 24 chromosomes of an embryo with greater than 97% accuracy within four hours, allowing for a fresh embryo transfer of a tested embryo, using Comprehensive Chromosome Screening (CCS). This study seeks to show that the transfer of a single CCS-normal embryo will result in delivery rates equal to those resulting from a two embryo transfer, the current standard of care in IVF.

Patients will undergo IVF according to the protocol recommended by their primary doctor. On the day of egg retrieval, all mature eggs will be fertilized by intracytoplasmic sperm injection (ICSI) per routine laboratory protocol. Embryos will then be cultured out to day 5 per routine laboratory procedure. The embryos will be assessed by the embryologist on day 5 to determine if the patient is a candidate for a fresh transfer. Patients who are a candidate for fresh transfer will be randomized into either the single embryo transfer of a chromosomally normal embryo group or the double, untested embryo group. Patients will have a 50:50 chance of being in the single or double embryo transfer group. Embryos in the single embryo group will undergo biopsy for CCS and patients will then undergo transfer of the morphologically best, chromosomally normal embryo. Additional embryos will be cryopreserved. Patients in the double embryo transfer group will undergo a two embryo transfer. Additional embryos will be cryopreserved. If patients are not a candidate for a fresh transfer (potentially because of endometrial lining development, risk of ovarian hyperstimulation syndrome, or embryos that are not suitable for biopsy on day 5), they will still be randomized into either the single or double embryo transfer group. Patients in the single embryo transfer group will have all embryos biopsied for CCS prior to being frozen. Patients will then immediately undergo a synthetic frozen embryo transfer cycle in accordance with their randomization. Patients in the double embryo transfer group will have their embryos frozen and will then immediately prepare for a synthetic frozen embryo transfer cycle in accordance with their randomization. Any patient who does not become pregnant during their fresh transfer cycle will immediately undergo a synthetic frozen embryo transfer cycle in accordance with their original randomization.

All clinical follow up will be per routine regarding pregnancy testing, early pregnancy monitoring and subsequent transfer of care to the patient's obstetrician. If clinical miscarriage occurs, cells from the products of conception will be collected, if possible, and submitted for genetic analysis. If the pregnancy progresses to delivery, a buccal swab (small swab touched to the inside of the baby's cheek) will be collected and submitted for genetic analysis.