We invited Dr Juan Carlos Castillo from the Instituto Bernabéu in Spain to give a presentation on “Recurrent and spontaneous miscarriages. Are donor eggs a cure?”
Recurrent pregnancy loss and spontaneous miscarriage are the incredibly sad sides of the joy of pregnancy. There is an expectation that other than morning sickness and swollen ankles, becoming pregnant and carrying a baby to term are easy feats. However, for many couples, that is simply not the case; assisted conception is required, and miscarriage can be a devastatingly painful reality.
In this webinar, recognised fertility author, speaker and expert Dr Castillo, discusses research into whether donor eggs could be the cure for those who live with the desolation of baby loss, however early into a pregnancy.
“Pregnancy requires little more than implantation of a developmentally competent embryo into the receptive endometrium” – simple hey? Yet, it’s not.
Sadly, 15-25% of pregnancies are clinically recognised as ending in a miscarriage, the majority of which will happen before a gestation period of ten weeks. Regrettably, around 4% of couples will experience recurrent pregnancy loss (RPL), which is defined as miscarrying in two, or more, pregnancies, from the time of conception until twenty-four weeks, in both natural and assisted conception. Whilst, technically, becoming and remaining, pregnant should be simple, we all know, that for many of us, it isn’t.
Dr Castillo’s research shows that both medical and family history should be used to tailor diagnostic investigations into RPL and, that in terms of prognosis, the maternal age and number of miscarriages are of utmost importance. The risk of pregnancy loss rapidly increases after a woman turns forty, with the lowest rate of miscarriage in those below thirty-five. Smoking, being significantly under or overweight, will also have an impact, as does caffeine and alcohol intake and high-intensity exercise. However, research has shown that there is no direct evidence which links stress and recurrent pregnancy loss; repeated miscarriage will, inevitably, cause both physical and mental pressure, but it is not to blame.
What causes miscarriage with donor eggs?
When looking into the medical reasons behind recurrent and spontaneous pregnancy loss, Dr Castillo advises that miscarriage is attributed to either embryonic or uterine factors, put simply; a problem with the embryo or the uterus. If embryonic factors are the cause, this could be due to chromosomal or other, developmental, abnormalities, and is likely to fall into one of two categories; cytogenetic, where there is an abnormal number of chromosomes in a cell, medically referred to as aneuploidy, or, the abnormalities could be structural. Studies estimate that circa 60% of sporadic miscarriages are due to cytogenic chromosomal abnormalities, and mainly as a result of a specific kind of aneuploidy; a trisomy. Trisomies are understood to be, in part, age-related.
However, these are not the only problems to affect an embryo and in 2-5% of RPL couples, structural abnormalities, due to unbalanced translocations, were found to be a factor. Unbalanced translocations occur when a portion of one chromosome is transferred to another, creating a loss, or gain, of genetic material, thus causing a chromosomal imbalance that could generate abnormalities and explain the miscarriages. Chromosomal imbalances can happen as a result of either parent. It isn’t female-specific.
Treatment options for embryonic abnormalities include an embryo biopsy, at the blastocyst (5-day) stage, in order for the cells to be genetically analysed. Depending on the outcome of the biopsy results, a change in the gametes could be suggested, e.g., use of a donor.
Not all pregnancy loss is due to embryonic anomalies though, and uterine factors can be the source of spontaneous or reoccurring miscarriage.
The advice, of Dr Castillo, is that all women, suffering from recurrent pregnancy loss, should have a uterine anatomy assessment.
There are now surgical correction procedures and medication available, which can help if an anatomic uterine factor is discovered to be the determinant of miscarriages.
Hormonal and metabolic factors should also be considered when studying pregnancy loss, specifically thyroid abnormalities. Thyroid hormones are critical for foetal development, and thyroid hormone disorders are known to be associated with loss of pregnancy. For couples experiencing RPL, testing of thyroid function is recommended and, should an issue be discovered, can usually be treated. Uncontrolled, or undiagnosed, diabetes, increased prolactin levels and vitamin D deficiencies could also be a cause, however, the evidence, linking these conditions to RPL, is inconsistent, and therefore routine testing is not currently recognised as a guideline recommendation.
In order for a pregnancy to be sustained, a normally functioning immune system is essential, and Dr Castillo discusses the “widely controversial” topic of testing for Natural Killer cells (NK cells). NK cells are a subtype of specialised lymphocytes that play a critical role in immune response, meaning the presence of such cells could affect the ability to develop a baby. The screening process consists of two tests; either blood analysis or studying tissue from an endometrial biopsy. However, Dr Castillo is keen to point out that huge technical challenges are faced when it comes to these tests, explaining how the collated results from blood and tissue can be extremely different, and cell numbers are known to fluctuate greatly during a woman’s menstrual cycle. As yet, there is currently still insufficient evidence to link this with RPL.
Miscarriage has a huge psychological effect on both women and men. However, however as heart-breaking as it is to experience recurring pregnancy loss, thanks to the wonder that is medical science, treatment and psychological support is now available.
Increased medical knowledge, and understanding, of the reproductive system and embryonic health, allows an insight into immunological conditions, chromosomal issues, and other fertility complaints, which can be factors in both conception and pregnancy loss. Fertility clinics should be there to offer help, initially in the form of tests and screening, and advise on the best plan of action for couples, whether that be a form of medication, the option of fertility treatments, and/or the use of donor eggs, in order to sustain a pregnancy and carry a baby to term.
Pregnancy loss is a highly emotional and heart-breaking moment in life. We offer below a complete transcript of the Questions & Answers from the webinar, which hopefully will shed some more light on fertility treatment for recurrent miscarriage and ways of preventing recurrent miscarriage.
Recurrent Miscarriages – Patients’ Success Stories
Recurrent Pregnancy Loss (RPL) – Success Stories