Miscarriage rates tripled in women exposed to higher magnetic field (MF) non-ionizing radiation

Higher exposure to magnetic fields (MFs) non-ionizing radiations nearly triples the risk of miscarriage in pregnant women compared to those who get lower exposure reports the results of prospective cohort study published online in Nature’s Scientific Reports.

The electromagnetic spectrum 

This study reaffirms the findings from earlier studies that non-ionizing radiations are not totally harmless, and they have biological effects on human health.  

The lead author Dr. De-Kun Li, a senior research scientist at the Kaiser Permanente Division of Research in Oakland, California call it a serious public health challenge as humans are ubiquitously exposed to both low frequency MFs generated by home appliances, transformers, powerlines etc and higher frequency MFs from cell phones, wireless networks, smart meter networks, cell towers and wireless devices.

The authors identified 900 women with a positive pregnancy test through the electronic medical record (EMR) laboratory database from bay area counties in Northern California. The MFs exposure was measured in milligauss (mG) through EMDEX Lite meter (Enertech Consultants Inc.) that the women carried throughout 24 hours during pregnancy.

The exposure was further classified as typical or atypical based on the women following her daily schedule or doing something apart from her routine because it was seen that there was a significant difference between exposure on a typical day vs atypical day.  

As the women were followed progressively into pregnancy till 20 weeks since the positive urine pregnancy test, the study was able to detect early miscarriages that earlier studies might have missed.

Women’s personal risk factors and obstetric history was ascertained along with presence or absence of other confounders to rule out bias. They were followed into pregnancy till miscarriages, end of pregnancy due to other reasons like ectopic or till they reach 20 weeks.

Cox Proportional Hazards regression model was used to examine the association between MFs exposures and miscarriage rates.

After adjusting for the known confounders like maternal age, race, education, smoking during pregnancy, and prior miscarriage, overall, pregnant women who had higher MF exposure during pregnancy (higher 3 quartiles) had a 48% greater risk of miscarriage than women who had lower MF exposure (in the lowest quartile): adjusted HR = 1.48, 95% confidence interval (CI): 1.03–2.14 

The association was stronger and significant when the data was examined for typical days vs atypical days, on which no association was observed.

Similarly, no difference was observed between women with (≥2) miscarriages vs women with no prior bad obstetric history. Although, the association was stronger in women who were exposed to the higher quartiles as opposed to women exposed to lowest quartile, no significant dose response relationship was observed.

The association was also consistent across different sources of MFs exposure.

This is the only study that used an objective measuring device (EMDEX Lite meter) to measure the radiations and were able to measure the effects prospectively in months instead of years as in cancer and other chronic diseases.

Prior studies have found an association between long term exposure to non-ionizing radiations and increased risk of brain cancer and low sperm counts.

The lead author Dr. Li stresses the importance of further studies in this subject area. Meanwhile she advices children and young adults, especially pregnant women to stay away from cell phones and other equipments that emit non-ionizing radiations.

Couples who are trying to conceive should also minimize their exposure by maintaining a safe distance from cell phone and other house hold appliances.

Abstract

Full text

Media courtesy: Daily Mirror, Vimeo.com, wireless hygiene 

A shorter inter-pregnancy interval after a miscarriage decreases the risk of repeat loss

A short inter-pregnancy interval of less than 3 months after a pregnancy loss, increases the chances of successful future pregnancy according to results of small study published electronically ahead of print in journal obstetrics and gynecology. 

  

The study was also presented at the Society for Reproductive Investigation's 64th Annual Meeting, March 15–18, 2017, Orlando, Florida. (Abstract- O-095)

There is no uniform consensus about the optimal pregnancy interval after a miscarriage. Some physician advising no delay, others advising a gap of at least 3 months, while the WHO guidelines recommending at least six months.

This prospective cohort study recruited 514 women over a period of 2 years (2010-2012), who have suffered a spontaneous pregnancy loss in their most recent pregnancy. The median maternal age was 30 years and nearly half of the women had a previous live birth.

The inter-pregnancy interval were modeled against risk of miscarriages, after adjusting for age, parity, race and BMI.  

Nearly 15 suffered a repeat pregnancy loss(n=81), and women with longest interpregnancy interval of 1 – 1.5 years had a 20% chance of repeat miscarriages as opposed to 7% chance in women whose conceived again within 3 months of the miscarriage (adjusted HR 0.33, 95% CI 0.16–0.71).

The drawback of the study was its small sample size.

The authors concluded that, “Contrary to guideline recommendations, we found that IPIs after pregnancy loss of less than three months are associated with the lowest risk of subsequent miscarriage for the first time in a prospective pregnancy cohort. This implies that counseling women to delay conception in the clinic may not be warranted.”

FDA evaluating the safety of oral fluconazole in pregnancy.

In the light of new evidence linking oral fluconazole to miscarriages the FDA is currently reviewing the safety of oral fluconazole as a vaginal yeast infection treatment in pregnancy. This review comes in the wake of Danish study published in JAMA which reports abnormalities at birth when  oral fluconazole is taken in higher dose of 400-800 mg/day.

It was a Nationwide register-based cohort study in Denmark from 1997-2013. From a cohort of 1,405, 663 pregnancies, 3315 women were exposed to oral fluconazole from 7 through 22 weeks’ gestation. About 147 experienced a spontaneous abortion compared with 563 among 13,246 unexposed matched women (HR 1.48).

The current FDA drug label states that data available from studies in people do not suggest an increased risk of problems during pregnancy or abnormalities in developing babies when women are exposed to a single 150 mg dose of oral fluconazole to treat vaginal yeast infections.

FDA cautions the healthcare professionals about the use of this drug until the review is complete. The agency has previously classified it as  pregnancy class D, meaning that there is evidence of risk to the fetus, but it may be used if the mother's condition is serious or life-threatening.

CDC guidelines also recommend only using topical antifungal products to treat pregnant women with vulvovaginal yeast infections, including for longer periods than usual if these infections persist or recur.

FDA is also urging people and researchers to report any untoward effects of the drug. It is also reviewing additional data related to the drug use in pregnancy.

In addition to its use as antifungal for vaginal yeast infection, it is also used to treat infection of mouth, and esophagus. fungal infection of the brain and spinal cord called cryptococcal meningitis.

References:

Mølgaard-Nielsen D, Svanström H, Melbye M, Hviid A, Pasternak B. Association Between Use of Oral Fluconazole During Pregnancy and Risk of Spontaneous Abortion and Stillbirth. JAMA. 2016;315(1):58-67. doi:10.1001/jama.2015.17844.

http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm497656.htm?source=govdelivery&utm_medium=email&utm_source=govdelivery