pregnancy

A Danish team has analysed a small dataset comprising 685 pregnant women and 302 of their daughters at three months of age to assess possible associations between foetal exposure to paracetamol and the infants’ ovarian function. Their study, published in the journal Human Reproduction Open, suggests that girls whose mothers took paracetamol during pregnancy had smaller ovaries and uteri, fewer ovarian follicles and lower levels of reproductive hormones. The authors point out that this is an observational study and therefore cannot assess whether the drug causes reproductive problems or whether these early differences are clinically significant.

A study has analysed structural changes in the female brain during the three main hormonal transitions: puberty, pregnancy and the menopause. To do this, using longitudinal neuroimaging – which records images of the brain over time – the researchers compared women transitioning from one hormonal phase to another with participants currently in those hormonal phases – more than 1,000 women in total. The results, published in Nature Communications, show that the transitions of puberty and pregnancy lead to a reduction in cortical grey matter, whilst women going through the menopause did not show a significant decrease in either cortical grey matter or total brain volume.

A study published in the journal Cell Host & Microbe analysed endometrial samples from 149 women aged between 20 and 45 who were undergoing treatment for infertility. The younger patients had a significantly higher abundance of a beneficial bacterium called Lactobacillus gasseri, the presence of which decreased with age. Furthermore, pregnant women had a higher abundance of these bacteria in the endometrium. In mouse models, older animals showed higher rates of embryo implantation when treated with L. gasseri derivatives. Despite these findings, the authors emphasise that further research is needed and warn women against self-medicating with over-the-counter L. gasseri products, as their effectiveness in treating infertility has not been validated.

Currently, only 48 per cent of newborns are exclusively breastfed, according to the WHO. A narrative review published in the Journal of Maternal-Fetal & Neonatal Medicine analyses three clinical practices during the first 48–72 hours after birth that may negatively affect the initiation and continuation of breastfeeding in healthy newborns: the perception that the volume of colostrum in breast milk is insufficient, restrictions on the use of dummies in maternity wards, and the early introduction of electric breast pumps.

Children whose mothers took high doses of vitamin D (2,800 IU/day) during pregnancy have better verbal and visual memory at the age of 10—among other cognitive functions—than children whose mothers took a standard dose of this vitamin (400 IU/day). This is the conclusion of a study, published in JAMA Network Open, based on a reanalysis of data from 498 children in another study on childhood asthma in Denmark.

A review published in The Lancet Psychiatry has examined the prevalence of major depressive disorder during pregnancy, the peripartum period—immediately before and after childbirth—and the postpartum period—up to twelve months after childbirth. The study, which used data from more than two million women and girls aged 10 to 59 from all regions of the world, showed that approximately one in 15 (6.8%) is affected by major depression during the year following childbirth and that the prevalence was highest during the first two weeks after childbirth (8.3%). The authors call for greater integration of screening, prevention, and treatment of this disorder during the peripartum period into current care models.

Around 15% of recognized pregnancies end in miscarriage, and it is estimated that almost half of all conceptions are lost in early stages, without people even realizing it. Now, a team from the United States and Denmark has analyzed data from more than 139,000 embryos from in vitro fertilization of nearly 23,000 couples and has found several genetic variants associated with a higher risk of miscarriage. Many of these are associated with meiosis, a key cell division process in sex cells. The authors, whose study is published in Nature, acknowledge that the new data will not allow for a precise estimation of individual risk, because the most important factors remain age and environmental elements.

There is no link between the use of paracetamol during pregnancy and an increased risk of autism, attention deficit hyperactivity disorder (ADHD) or intellectual disability among children, according to a meta-analysis published in The Lancet Obstetrics, Gynaecology, & Women’s Health. 

The BMJ has published a meta-analysis about weight gain in pregnant women and the risks it poses to their health and that of their babies. According to the study, 68% of pregnancies involve weight gain that is either above or below the recommended level, which is associated with complications such as premature birth, high birth weight, and admission to intensive care. The review included data from 1.6 million women from various regions of the world and different income levels, recorded between 2009 and 2024.

A team has analysed estimated data on exposure to pollution during and after pregnancy and its possible link to a diagnosis of autism in more than two million births in Canada between 2002 and 2022. Their findings are that greater exposure to small PM_2.5 particles containing sulphate or ammonium is associated with a higher likelihood of receiving a diagnosis of autism in the first five years of life. A slightly increased proportion was also observed with greater exposure to ozone during certain weeks of pregnancy and in the first year of life. The results are published in the journal JAMA Network Open.