Women who suffer severe complications during their first pregnancy or delivery are less inclined to have more babies, according to a study published in JAMA by researchers at Karolinska Institutet. For Sweden, given its recent steady decline in birth rate, the researchers propose monitoring in antenatal care to address the problem.
“The clinical monitoring of these women is essential, and they need individualised advice on possible future pregnancies,” says the study’s first author Eleni Tsamantioti, doctoral student at the Department of Medicine in Solna, Karolinska Institutet.
Reduced fertility
Birth rates and fertility have both been in steady decline in Sweden over the past years. In this new population-based study, the researchers have studied the association between severe maternal morbidity in first-time mothers and the likelihood of their having a second baby. The study comprised over a million women in Sweden who had their first baby between 1999 and 2021.
“We found that the likelihood of having more children was much lower in women who had experienced severe complications during their first pregnancy, delivery or postnatal period,” says the study’s last author Neda Razaz, associate professor at the same department. “Such events can often have a physical and mental impact on women for a long time to come.”
All in all, 3.5% of the first-time mothers in the study suffered serious complications and were 12% less likely to have a second baby. Most impacted were women who had experienced cardiac complications, a ruptured uterus or severe mental health problems, who were 50% less likely to have another birth than women who had not experienced such complications.
Monitoring in antenatal care
Women who needed respiratory care or who suffered a cerebrovascular accident like stroke or intracranial haemorrhage were 40% less likely to have a second baby. Acute kidney failure, severe preeclampsia and blood clotting were also associated with a lower probability of a second pregnancy. The researchers also compared the women with any sisters they had to control for familial factors.
“The reasons are hard to speculate on and may result from multiple factors, such as decreased desire for more children, trauma, infertility related to psychiatric medications, or lack of health counselling,” says Tsamantioti. “Proper support and monitoring by antenatal care staff is therefore essential for women who have suffered serious health problems during pregnancy or delivery.”
Women who are being treated for asthma are more likely to miscarry and need fertility treatment to get pregnant, according to a large study presented at the European Respiratory Society (ERS) Congress in Vienna, Austria. The study also suggests that most women with asthma are able to have babies.
The study was presented by Dr Anne Vejen Hansen from the department of respiratory medicine at Copenhagen University Hospital, Denmark.
She said: “Asthma is common in women of reproductive age. Previous studies have shown that it takes women with asthma longer to get pregnant than those without asthma when undergoing fertility treatment, and that asthmatic women who succeed in getting pregnant have more often had fertility treatment than non-asthmatic women. But most existing studies are on women who have actually got pregnant, so we wanted to examine fertility outcomes on a national scale, to also include those that might not become pregnant at all.”
The team analysed reproductive outcomes for all Danish women born from 1976 to 1999, following them from 1994 to 2017. In total, 769,880 women were included and followed; anyone who took anti-asthma medication on a regular basis was classified as asthmatic.
They found that women with asthma experienced a higher degree of foetal loss compared to women without asthma (17.0% vs. 15.7%) and more use of fertility treatment (5.6% vs. 5.0%). However, the proportion who subsequently gave birth was 77% in women with and without asthma, suggesting that asthma does not seem to affect the number of live births.
Dr Vejen Hansen said: “We found that women fulfilling the definition of asthma had a higher rate of foetal loss and an increased use of fertility treatment. The more severe the asthma and the more flare ups the women experienced, the more likely they were to need fertility treatment. Why this is, is not clear. It might be related to systemic inflammation throughout the body, including women’s reproductive organs.
“But the numbers also show that these same women who redeem asthma medication still have as many live births in the end as women who don’t. This suggests that most women with asthma probably do manage to become pregnant and have babies in the end.
“We also plan to investigate the possible effect of male asthma on fertility, and, therefore, have another similar registry-based study in the pipeline.”
Professor Lena Uller is Chair of the ERS group on Airway Pharmacology and Treatment and Head of the Respiratory Immunopharmacology research group at Lund University, Sweden, and was not involved in the research. She said: “It’s reassuring that women seem to have the same live birth rate regardless of their asthma. However, the results also indicate that women with asthma should take into consideration potential reproductive challenges in their family planning. If women with asthma are worried about their fertility, they should speak to their doctor.
“The results of this study also underscore the importance of managing asthma in reproductive-aged women. The fact that the more severe the asthma, the more the problems with fertility, suggests that uncontrolled asthma is the problem and we should be helping women to get their asthma under control.”
A new study by Dana-Farber Cancer Institute investigators, which tracked nearly 200 young women treated for breast cancer, found that the majority of those who tried to conceive during a median of 11 years after treatment were able to become pregnant and give birth to a child.
The findings, to be presented at the 2024 Annual Meeting of the American Society of Clinical Oncology (ASCO), are particularly noteworthy because they answer several questions left open by previous studies of pregnancy and live-birth rates among breast cancer survivors, the study authors say.
“Earlier studies were limited because they included select subgroups of patients, followed patients for a relatively short period of time, and didn’t ask participants, during the study period, if they had attempted pregnancy,” says the study’s senior author, Ann Partridge, MD, MPH, the founder and director of the Program for Young Adults with Breast Cancer at Dana-Farber. “This study was designed to address those gaps by tracking pregnancy and live birth rates among a group of breast cancer survivors and patients who indicated they’d attempted to conceive following their cancer diagnosis.”
The patients in the study were participants in the Young Women’s Breast Cancer Study, which is tracking the health of a group of women diagnosed with breast cancer at or under age 40. Of 1213 eligible participants, 197 reported an attempt of pregnancy over a median follow-up period of 11 years. Within this latter group, the median age at the time of diagnosis was 32 years, and most were diagnosed with hormone receptor-positive breast cancer. Participants were periodically surveyed about whether they had tried to become pregnant and whether they had conceived and given birth.
Over the course of the study, 73% of women attempting to conceive achieved a pregnancy and 65% had a live birth, researchers found. Those who opted for fertility preservation by egg/embryo freezing before cancer treatment tended to have a higher live birth rate, while older participants tended to have lower pregnancy and live birth rates
Participants in the study had breast cancers ranging from stage 0, which are non-invasive and confined to the inside of the milk duct, to stage III, in which the cancer has spread to the lymph nodes. There was no statistically significant association with stage of the disease at diagnosis and achieving a pregnancy or live birth.
“For many young women with breast cancer, the ability to have children following treatment is a major concern,” says the study’s first author, Kimia Sorouri, MD, MPH, of Dana-Farber. “The findings of our study can be helpful when counselling patients about fertility issues. The finding that egg/embryo freezing before treatment was associated with a higher live birth rate underscores the need for accessibility to fertility preservation services for this population.”
Some of the final work of a late University of Virginia School of Medicine scientist has opened the door for life-saving new treatments for solid cancer tumours, including breast cancer, lung cancer and melanoma.
Prior to his sudden death in 2016, John Herr, PhD, had been collaborating with Craig L. Slingluff Jr, MD, to investigate the possibility that a protein recently discovered at Herr’s lab could be a viable cancer treatment target.
Eight years of research has borne that idea out: Herr’s research into the SAS1B protein could lead to “broad and profound” new treatments for multiple cancers, many of which are very difficult to treat, Slingluff reports in a new scientific paper in the Journal for ImmunoTherapy of Cancer. Herr is listed as a senior author on the paper.
“John was very excited about this protein SAS1B to be a valuable new target on human cancers, and I am delighted that our findings together further support his hope to make such a difference,” said Slingluff, a surgical oncologist and translational immunologist at UVA Health and the UVA School of Medicine. “The work we published included work done by Dr Herr and his team over a period of years, as well as our subsequent work together; so, I am glad that the journal agreed with our request to include John as a senior author.”
Promising New Cancer Target
Herr’s lab was not originally focused on cancer – he was the head of UVA’s Center for Research in Contraceptive and Reproductive Health. In that role, he developed the first home fertility test for men, SpermCheck, which is available in pharmacies across the country. But his discoveries about the SAS1B protein found in developing eggs in women could pave the way for new cancer immunotherapies.
While SAS1B is found inside female reproductive cells called oocytes, it is also found on the surface of many different solid cancer cells, Slingluff’s new research verifies. Importantly, it did not appear on the surface of any of the other normal cells Slingluff’s laboratory tested. That suggests that doctors may be able to develop use antibody-based immunotherapy – such as antibody-drug conjugates or CAR T-cell therapy, a strength of UVA Health – to attack the cancer cells while sparing healthy tissue.
“Selectively targeting SAS1B has the potential to have broad and profound impact on the treatment, and therefore reduction in mortality, of multiple malignancies,” Slingluff and his colleagues write in their new paper.
While much more work needs to be done, the new findings are promising. If the approach is successful, it could be a big step forward in cancer care. Many solid-organ cancers are extremely difficult to treat, and patients often have few good treatment options, Slingluff notes.
“Immune therapy is revolutionising treatment of human cancers,” Slingluff said. “But some cancers have been particularly resistant to immune therapy because of the lack of good targets on those cancers. We hope that this work that John Herr started will bring new hope to patients with those cancers.”
While various environmental and lifestyle factors have been proposed to explain the decline in semen quality observed over the last fifty years, the role of mobile phones has yet to be demonstrated. In a major cross-sectional study, researchers in Switzerland showed that frequent use of mobile phones is associated with a lower sperm concentration and total sperm count, although causation cannot be established. No association was seen between mobile phone use and low sperm motility and morphology. Read the results in Fertility & Sterility.
Semen quality is determined by the assessment of parameters such as sperm concentration, total sperm count, sperm motility and sperm morphology. According to the values established by the World Health Organization (WHO), a man will most probably take more than one year to conceive a child if his sperm concentration is below 15 million/mL, with the odds of pregnancy will decrease if the sperm concentration is below 40 million/mL.
Many studies have shown that semen quality has decreased over the last fifty years. Sperm count is reported to have dropped from an average of 99 million sperm/mL to 47 million/mL. This phenomenon is thought to be the result of a combination of environmental factors (endocrine disruptors, pesticides, radiation) and lifestyle habits (diet, alcohol, stress, smoking).
Assessing the impact of mobile phones
Is the mobile phone also to blame? After conducting the first national study (2019) on the semen quality of young men in Switzerland, a team from the University of Geneva (UNIGE) has published the largest cross-sectional study on this topic. It is based on data from 2886 Swiss men aged 18 to 22, recruited between 2005 and 2018 at six military conscription centres.
In collaboration with the Swiss Tropical and Public Health Institute (Swiss TPH), scientists studied the association between semen parameters of 2886 men and their use of mobile phones. ‘‘Men completed a detailed questionnaire related to their lifestyle habits, their general health status and more specifically the frequency at which they used their phones, as well as where they placed it when not in use,’’ explains Serge Nef, full professor in the Department of Genetic Medicine and Development at the UNIGE Faculty of Medicine and at the SCAHT – Swiss Centre for Applied Human Toxicology, who co-directed the study.
These data revealed an association between frequent use and lower sperm concentration. The median sperm concentration was significantly higher in the group of men who did not use their phone more than once a week (56.5 million/mL) compared with men who used their phone more than 20 times a day (44.5 million/mL). This difference corresponds to a 21% decrease in sperm concentration for frequent users (> 20 times/day) compared to rare users (< once/day).
Is 4G less harmful than 2G?
This inverse association was found to be more pronounced in the first study period (2005-2007) and gradually decreased with time (2008-2011 and 2012-2018). ‘‘This trend corresponds to the transition from 2G to 3G, and then from 3G to 4G, that has led to a reduction in the transmitting power of phones,’’ explains Martin RÖÖsli, associate professor at Swiss TPH.
‘‘Previous studies evaluating the relationship between the use of mobile phones and semen quality were performed on a relatively small number of individuals, rarely considering lifestyle information, and have been subject to selection bias, as they were recruited in fertility clinics. This has led to inconclusive results,’’ explains Rita Rahban, senior researcher and teaching assistant in the Department of Genetic Medicine and Development in the Faculty of Medicine at the UNIGE and at the SCAHT, first author and co-leader of the study.
It doesn’t matter where you put your phone
Data analysis also seems to show that the position of the phone – for example, in a trouser pocket – was not associated with lower semen parameters. ‘‘However, the number of people in this cohort indicating that they did not carry their phone close to their body was too small to draw a really robust conclusion on this specific point,’’ adds Rita Rahban.
This study, like most epidemiologic studies investigating the effects of mobile phone use on semen quality, relied on self-reported data, which is a limitation. By doing so, the frequency of use reported by the individual was assumed to be an accurate estimate of exposure to electromagnetic radiation. To address this limitation, a study funded by the Federal Office for the Environment (FOEN) was launched in 2023. Its aim is to directly and accurately measure exposure to electromagnetic waves, as well as the types of use – calls, web navigation, sending messages – and to assess their impact on male reproductive health and fertility potential. The data will be collected using an application that each future participant will download to their mobile phone. The research team is actively recruiting participants for this study.
The aim is also to better describe the mechanism of action behind these observations. ‘‘Do the microwaves emitted by mobile phones have a direct or indirect effect? Do they cause a significant increase in temperature in the testes? Do they affect the hormonal regulation of sperm production? This all remains to be discovered,’’ concludes Rita Rahban.
The ketogenic (keto) diet may lower testosterone levels in women with polycystic ovary syndrome (PCOS), according to a new paper published in the Journal of the Endocrine Society. The diet also appeared to lower follicle-stimulating hormone (FSH) levels, which may thereby improve the chances of ovulating. These improvements in hormonal balance could help alleviate fertility problems.
PCOS is the most common hormone disorder in women, affecting 7–10% of women of childbearing age. It can cause infertility and raises the risk of developing diabetes, obesity and other metabolic health problems.
Women with PCOS have at least two of these signs:
Elevated levels of testosterone and other androgen hormones associated with male reproduction,
Irregular periods, and
Large ovaries with many small follicles.
The keto diet is a high fat, low carbohydrate diet that has shown promising effects in women with PCOS. Studies have shown that it may help women lose weight and maintain weight loss, improve their fertility, optimise their cholesterol levels and normalise their menstrual cycles.
“We found an association between the ketogenic diet and an improvement in reproductive hormone levels, which influence fertility, in women with PCOS,” said study author Karniza Khalid, MBBS, MMedSc, of the Ministry of Health Malaysia in Kuala Lumpur, Malaysia. “These findings have important clinical implications, especially for endocrinologists, gynaecologists and dieticians who, in addition to medical treatment, should carefully plan and customise individual diet recommendations for women with PCOS.”
The researchers conducted a meta-analysis of clinical trials in women with PCOS on the keto diet and examined the diet’s effects on their reproductive hormones (FSH, testosterone and progesterone) and weight change.
They found women with PCOS who were on the keto diet for at least 45 days saw significant weight loss and an improvement in their reproductive hormone levels. Their FSH ratio was lower, which means they may have a better chance of ovulating. The women also had lower testosterone levels, which could help with excess hair growth and other symptoms of excess male sex hormones.
With an emphasis on fruits, vegetables and legumes, the Mediterranean diet has long been applauded for its multiple health benefits. Now, new research shows that it may also help overcome infertility, making it a non-intrusive and affordable strategy for couples trying to conceive.
Specifically, researchers identified that the anti-inflammatory properties of a Mediterranean diet can improve couples’ chances of conception.
Infertility is a global health concern affecting 48 million couples and 186 million individuals worldwide.
UniSA researcher, Dr Evangeline Mantzioris, says modifying preconception nutrition is a non-invasive and potentially effective means for improving fertility outcomes.
“Deciding to have a baby is one of life’s biggest decisions, but if things don’t go as planned, it can be very stressful for both partners,” Dr Mantzioris says.
“Research shows inflammation can affect fertility for both men and women, affecting sperm quality, menstrual cycles, and implantation. So, in this study we wanted to see how a diet that reduces inflammation – such as the Mediterranean diet – might improve fertility outcomes.
“Encouragingly, we found consistent evidence that by adhering to an anti-inflammatory diet – one that includes lots of polyunsaturated or ‘healthy’ fats, flavonoids (such as leafy green vegetables), and a limited amount of red and processed meat – we can improve fertility.”
The Mediterranean diet is primarily plant-based, and includes whole grains, extra virgin olive oil, fruits, vegetables, beans and legumes, nuts, herbs, and spices. Yoghurt, cheese, and lean protein sources such as fish, chicken, or eggs; red and processed meats are only eaten in small amounts.
In comparison, a western diet comprises excessive saturated fats, refined carbohydrates, and animal proteins, making it energy-dense and lacking dietary fibre, vitamins, and minerals. Typically, a western diet is associated with higher levels of inflammation.
Chronic use of marijuana could greatly impact male fertility and reproductive outcomes, according to a new study appearing in Fertility & Sterility. This is the first study to assess the impacts of typical substance use on testicular function via a mode of delivery, and dosage.
Robust research in animal models has shown that cannabis negatively impacts male fertility. Researchers monitored the reproductive systems of healthy male nonhuman primates following exposure to THC, the main psychoactive ingredient in marijuana.
The nonhuman primates in the study received a THC edible once daily over the course of seven months. Their THC dose was based on published medical marijuana acclimation recommendations for humans, and was increased every 70 days in alignment with the animals’ sperm development cycle. Dose adjustments were made until it reached the equivalent of a heavy medical marijuana dose in humans. Semen samples were collected at baseline before initiation of THC, and again at the end of each THC dosing timepoint.
The study found that THC use was linked to significant adverse impacts to the animals’ reproductive hormones, including decreased levels of testosterone and severe testicular shrinkage. “Specifically, we observed a greater than 50% decrease in testicular size,” said senior author Jamie Lo, MD, MCR. “Unfortunately, these effects appeared to worsen as the THC dose was increased, suggesting a possible dose-dependent effect.”
These results align with Dr Lo’s previous studies indicating similar THC-associated impacts to female reproductive hormones and the menstrual cycle.
“These early findings are concerning from a clinical standpoint,” said study lead author Jason Hedges, MD, PhD. “Even moderate doses could have a profound impact on fertility outcomes. While family planning may not be top of mind for those in their late teens and early 20s, the longer-term effects of THC on male reproductive health are not well-defined; it is possible that THC could cause lasting impacts that may alter family planning later in life.”
The researchers will continue to explore the relationship between THC and reproductive health in both male and female nonhuman primates, examining longer term THC exposure impacts, including changes to sperm count and motility, and whether discontinuing use of THC products could reverse adverse effects.
Vaccination against COVID did not affect fertility outcomes in patients undergoing in-vitro fertilisation (IVF), according to a new study. The findings, which were published in Obstetrics & Gynecology, add to the growing body of evidence providing reassurance that COVID vaccination does not affect fertility.
Investigators compared rates of fertilisation, pregnancy, and early miscarriage in IVF patients who had received two doses of vaccines manufactured by Pfizer or Moderna with the same outcomes in unvaccinated patients.
“The study found no significant differences in response to ovarian stimulation, egg quality, embryo development, or pregnancy outcomes between the vaccinated compared to unvaccinated patients.” said first author Devora Aharon, MD.
The study involved patients whose eggs were frozen and then thawed for in vitro fertilisation and womb transfer, and patients who underwent medical treatment to stimulate the development of eggs. The two groups of patients who underwent frozen-thawed embryo transfer (214 vaccinated and 733 unvaccinated) had similar rates of pregnancy and early pregnancy loss. The two groups of patients who underwent ovarian stimulation (222 vaccinated and 983 unvaccinated) had similar rates of eggs retrieved, fertilisation, and embryos with normal numbers of chromosomes, among several other measures.
The authors of the study anticipate that the findings will ease the anxiety of people considering pregnancy.
Patients undergoing IVF treatment are closely tracked, enabling the researchers to capture early data on the implantation of embryos in addition to pregnancy losses that might be undercounted in other studies.
Previous studies have found that COVID vaccination helped protect pregnant persons (already at greater risk from severe illness and death from COVID) from severe illness, conferred antibodies to their infants, and did not raise the risk of preterm birth or foetal growth problems.
A study found birth rates among middle-aged women in Northern European increased thanks to assisted reproductive technologies.
The study examined the total population of women aged 40–49 years between 2008–2018 in Denmark, Norway, and Sweden, birth rates increased in Denmark and Sweden, and births resulting from assisted reproductive technology doubled in all three countries. The findings were published in Acta Obstetricia et Gynecologica Scandinavica.
The study found that use of hormonal contraception increased among women aged 40–44 years in Denmark from 24% to 31%, in Sweden from 27% to 30%, and in Norway from 22% to 24%. Additionally, birth rates among women 40–44 years increased from 9.5 to 12 per 1000 women in Denmark and from 11.7 to 14.3 per 1,00 in Sweden, while they remained stable in Norway at approximately 11 per 1000 women.
In women aged 40–49 years, there was a doubling of assisted conceptions in Denmark from 0.71 to 1.71 per 1000 women; in Sweden from 0.43 to 0.81 per 1000; and in Norway from 0.25 to 0.53 per 1000. The study also found that Sweden had the highest induced abortion rate (7.7 to 8.1 per 1000 women) in women aged 40–49 years during the study period.
“This study confirms the trend of postponing childbirth observed for most of Europe and demonstrates the important role of assisted reproductive technology on birth rates in this age group,” said lead author Ingela Lindh, MD, of Sahlgrenska University Hospital. “The study provides valuable information to improve women’s knowledge about their fertility.”
