USC Fertility

Genetic Causes of Pregnancy Loss

USC Fertility helps couples with recurrent pregnancy loss

About 5% of couples that attempt to conceive will experience the heartbreak of recurrent pregnancy loss, RPL, the term used when a woman experiences two or more miscarriages. The clinical causes of RPL can vary. Some couples experience pregnancy loss due to factors affecting the uterine environment, and some losses occur for reasons that can never be determined. But a significant number of RPL cases result from genetic and chromosomal factors that occur during the earliest stages of embryonic development.

Our Los Angeles Fertility center offers assisted reproductive technology (ART) to help couples identify a genetic error that may interfere with a healthy pregnancy. We can provide couples undergoing IVF with a preimplantation genetic diagnosis when an inheritable genetic issue exists. Many couples experiencing recurrent miscarriage benefit from preimplantation genetic testing for aneuploidy (PGT-A), formerly PGS. The expert team at our Los Angeles fertility center will discuss with you the best ways to prevent and predict the genetic abnormalities that may cause RPL.

Two Forms of Genetic RPL

Genetic RPL may involve any of several errors that take place in the nucleus of embryonic cells as they divide and replicate.

  • In some cases, entire chromosomes may be missing or may appear in excess.
  • In other cases, small fragments of a chromosome may experience insertions, deletions or duplications of genetic material in distinct regions.

In most cases, genetic RPLs can be divided into two categories: issues that are inherited from one or both parents, and issues that occur spontaneously in a newly formed embryo.

Parental chromosomal abnormalities occur in about 3-5% of couples who experience RPL. If genetic complications are inherited, preimplantation genetic testing for monogenic disorders (PGT-M), formerly PGD, may be able to help some couples prevent the risk of passing on a genetic error at conception.

But spontaneous incidents of aneuploidy can occur even in cases in which both parents appear to be chromosomally normal. According to the American Society for Reproductive Medicine, “chromosome abnormalities occur for no known reason in up to 60% of first-trimester miscarriages.” This is the point at which PGT-A can help. The IVF lab technique decreases the likelihood of transferring chromosomally abnormal, or aneuploid, embryos.

In either case, though many factors remain unclear, a fertility specialist can offer vital support to couples that are experiencing recurrent pregnancy loss. At our Los Angeles fertility center, our experts help couples find answers and evaluate their options for PGT-A or PGT-M. For more information, contact our caring and compassionate team to arrange a consultation.