Markers of vitamin D metabolism and premenstrual symptoms in healthy women with regular cycles

STUDY QUESTION

Are insufficient 25-hydroxyvitamin D (25(OH)D) concentrations, and other markers of vitamin D metabolism, associated with premenstrual symptoms in healthy women with regular menstrual cycles?

SUMMARY ANSWER

25(OH)D insufficiency was associated with specific physical premenstrual symptoms, while no associations were observed with psychological symptoms or with other markers of vitamin D metabolism.

WHAT IS KNOWN ALREADY

Prior studies evaluating vitamin D and premenstrual symptoms have yielded mixed results, and it is unknown whether 25(OH)D insufficiency and other markers of vitamin D metabolism are associated with premenstrual symptoms.

STUDY DESIGN, SIZE, DURATION

We used two cohorts of women with regular menstrual cycles; 1191 women aged 18-40 years in EAGeR (cross-sectional analysis of a prospective cohort within a randomized trial) and 76 women aged 18-44 years in BioCycle (prospective cohort). In EAGeR, premenstrual symptoms over the previous year were assessed at baseline, whereas in BioCycle, symptoms were assessed prospectively at multiple points over two menstrual cycles with symptoms queried over the previous week. In both cohorts, symptomatology was assessed via questionnaire regarding presence and severity of 14 physical and psychological symptoms the week before and after menses. Both studies measured 25(OH)D in serum. We also evaluated the association of additional markers of vitamin D metabolism and calcium homeostasis, including intact parathyroid hormone (iPTH), calcium (Ca), fibroblast growth factor 23 (FGF23), and 1,25 dihydroxyvitamin D (1,25(OH)2D) with premenstrual symptoms in the BioCycle cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One cohort of women actively seeking pregnancy (Effects of Aspirin in Gestation and Reproduction (EAGeR)) and one cohort not seeking pregnancy (BioCycle) were evaluated. Log-binomial regression was used to estimate risk ratios (RR) and 95% CIs for associations between insufficient 25(OH)D (<30 ng/ml) and individual premenstrual symptoms, adjusting for age, BMI, race, smoking, income, physical activity, and season of blood draw.

MAIN RESULTS AND THE ROLE OF CHANCE

25(OH)D insufficiency was associated with increased risk of breast fullness/tenderness (EAGeR RR 1.27, 95% CI 1.03, 1.55; BioCycle RR 1.37, 95% CI 0.56, 3.32) and generalized aches and pains (EAGeR RR 1.33, 95% CI 1.01, 1.78; BioCycle 1.36, 95% CI 0.41, 4.45), though results were imprecise in the BioCycle study. No associations were observed between insufficient 25(OH)D and psychological symptoms in either cohort. In BioCycle, iPTH, Ca, FGF23, and 1,25(OH) 2D were not associated with any premenstrual symptoms.

LIMITATIONS, REASONS FOR CAUTION

Results from the EAGeR study were limited by the study design, which assessed both 25(OH)D at baseline and individual premenstrual symptoms over the past year at the baseline. As such, reverse causality is a potential concern. Though premenstrual symptoms were assessed prospectively in the BioCycle cohort, the power was limited due to small sample size. However, results were fairly consistent across both studies.

WIDER IMPLICATIONS OF THE FINDINGS

Serum 25(OH)D may be associated with risk and severity of specific physical premenstrual symptoms.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (Contract nos. HHSN267200603423, HHSN267200603424, and HHSN267200603426). JG.R. and D.L.K. have been funded by the NIH Medical Research Scholars Program, a public-private partnership jointly supported by the NIH and generous contributions to the Foundation for the NIH by the Doris Duke Charitable Foundation (Grant #2014194), the American Association for Dental Research, the Colgate Palmolive Company, Genentech, and other private donors. For a complete list, visit the foundation website at http://www.fnih.org. The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT00467363.

Cannabis use while trying to conceive: a prospective cohort study evaluating associations with fecundability, live birth and pregnancy loss

STUDY QUESTION

Is cannabis use assessed via urinary metabolites and self-report during preconception associated with fecundability, live birth and pregnancy loss?

SUMMARY ANSWER

Preconception cannabis use was associated with reduced fecundability among women with a history of pregnancy loss attempting pregnancy despite an increased frequency of intercourse.

WHAT IS KNOWN ALREADY

Cannabis use continues to rise despite limited evidence of safety during critical windows of pregnancy establishment. While existing studies suggest that self-reported cannabis use is not associated with fecundability, self-report may not be reliable.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was carried out including 1228 women followed for up to six cycles while attempting pregnancy (2006 to 2012), and throughout pregnancy if they conceived.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 18-40 years with a history of pregnancy loss (n = 1228) were recruited from four clinical centers. Women self-reported preconception cannabis use at baseline and urinary tetrahydrocannabinol metabolites were measured throughout preconception and early pregnancy (up to four times during the study: at baseline, after 6 months of follow-up or at the beginning of the conception cycle, and weeks 4 and 8 of pregnancy). Time to hCG-detected pregnancy, and incidence of live birth and pregnancy loss were prospectively assessed. Fecundability odds ratios (FOR) and 95% CI were estimated using discrete time Cox proportional hazards models, and risk ratios (RRs) and 95% CI using log-binomial regression adjusting for age, race, BMI, education level, baseline urine cotinine, alcohol use and antidepressant use.

MAIN RESULTS AND THE ROLE OF CHANCE

Preconception cannabis use was 5% (62/1228), based on combined urinary metabolite measurements and self-report, and 1.3% (11/789) used cannabis during the first 8 weeks of gestation based on urinary metabolites only. Women with preconception cannabis use had reduced fecundability (FOR 0.59; 95% CI 0.38, 0.92). Preconception cannabis use was also associated with increased frequency of intercourse per cycle (9.4 ± 7 versus 7.5 ± 7 days; P = 0.02) and higher LH (percentage change 64%, 95% CI 3, 161) and higher LH:FSH ratio (percentage change 39%, 95% CI 7, 81). There were also suggestive, though imprecise, associations with anovulation (RR 1.92, 95% CI 0.88, 4.18), and live birth (42% (19/45) cannabis users versus 55% (578/1043) nonusers; RR 0.80, 95% CI 0.57, 1.12). No associations were observed between preconception cannabis use and pregnancy loss (RR 0.81, 95% CI 0.46, 1.42). Similar results were observed after additional adjustment for parity, income, employment status and stress. We were unable to estimate associations between cannabis use during early pregnancy and pregnancy loss due to limited sample size.

LIMITATIONS, REASONS FOR CAUTION

Owing to the relatively few cannabis users in our study, we had limited ability to make conclusions regarding live birth and pregnancy loss, and were unable to account for male partner use. While results were similar after excluding smokers, alcohol use and any drug use in the past year, some residual confounding may persist due to these potential co-exposures.

WIDER IMPLICATIONS OF THE FINDINGS

These findings highlight potential risks on fecundability among women attempting pregnancy with a history of pregnancy loss and the need for expanded evidence regarding the reproductive health effects of cannabis use in the current climate of increasing legalization.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (Contract numbers: HHSN267200603423, HHSN267200603424, HHSN267200603426, HHSN275201300023I). Jeannie G. Radoc has been funded by the National Institutes of Health Medical Research Scholars Program, a public-private partnership supported jointly by the National Institutes of Health and generous contributions to the Foundation for the National Institutes of Health from the Doris Duke Charitable Foundation (DDCF Grant # 2014194), Genentech, Elsevier, and other private donors. The authors report no conflict of interest in this work and have nothing to disclose.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT00467363.

Preconception antiphospholipid antibodies and risk of subsequent early pregnancy loss

Objectives To prospectively estimate the association of preconception antiphospholipid antibodies (aPL) with subsequent pregnancy loss using a cohort design. aPL have been associated with recurrent early pregnancy loss (EPL) prior to 10 weeks in previous case-control studies. Prospective ascertainment of pregnancy loss is challenging, as most women do not seek care prior to EPL. Methods Secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial of preconception low-dose aspirin. Preconception anticardiolipin (aCL) and anti-β2-glycoprotein-I (a-β2-I) were assessed in 1208 women with one or two prior pregnancy losses and no more than two prior live births. Comparison cohorts were defined by positive aPL (+aPL) or negative aPL (-aPL) status. All women were followed for six menstrual cycles while trying to conceive; if successful, they underwent an ultrasound at 6-7 weeks' gestation. EPL was defined as loss prior to 10 weeks' gestation; embryonic loss was loss after visualization of an embryo but prior to 10 weeks; clinical loss was any loss after visualization of an embryo (with or without fetal cardiac activity detected). Results In total, 14/1208 (1%) tested positive for +aPL. 786/1208 (65%) women had positive human chorionic gonadotropin during the study period, of which 9/786 (1%) had +aPL. Of the 786 pregnant women, 589 (75%) had live births and 24% had pregnancy losses. Women with +aPL experienced EPL at similar rates as women with -aPL, 44% vs 21% (aRR 2.4, 95% confidence interval (CI) 0.5-10.9). Embryonic loss was more common in women with +aCL IgM (aRR 4.8, 95% CI 1.0-23.0) and in women with two positive aPL. Clinical pregnancy loss was more common in women with positive a-β2-I IgM (50% vs 16.5%, aRR 3.7, 95% CI 1.3-10.8). Conclusion Positive levels of aPL are rare in women with one or two prior pregnancy losses and are not clearly associated with an increased rate of subsequent loss. Clinical trial registration The original source study was registered at ClinicalTrials.gov (#NCT00467363).

Recent attempted and actual weight change in relation to pregnancy loss: a prospective cohort study

OBJECTIVE

To assess weight change and attempted weight loss during the 12-18 months before spontaneous conception in relation to the risk of pregnancy loss.

DESIGN

Prospective cohort study.

SETTING

United States, 2007-2011.

METHODS

Women (n = 629) who were attempting pregnancy reported at baseline any weight loss attempts over the past 12 months, and their minimum and maximum weights during that time. Follow up lasted one to six menstrual cycles and throughout pregnancy. Using bodyweight measured at 4 weeks' gestation, participants were categorised as having weight loss ≥5%, weight gain ≥5%, both, or neither, over the previous 12-18 months. Log-binomial models adjusted for potential confounders.

MAIN OUTCOME MEASURES

Risk ratio (RR) and 95% confidence interval (CI) of pregnancy loss.

RESULTS

Attempted weight loss was reported by 44% of women and actual weight loss by 11%, but neither was consistently associated with pregnancy loss. The RR for recent weight gain ≥5% was 1.65 (CI 1.09, 2.49).

CONCLUSIONS

Weight gain over the period spanning 12-18 months pre-conception to 4 weeks' gestation may increase the risk of pregnancy loss among fertile women with prior pregnancy losses. Attempted and actual weight loss were not associated with pregnancy loss; however, replication is needed from larger studies with data on particular weight-loss methods.

TWEETABLE ABSTRACT

Recent weight gain before and around the time of conception may increase the risk of pregnancy loss.

Comparison of methods for identifying small-for-gestational-age infants at risk of perinatal mortality among obese mothers: a hospital-based cohort study

OBJECTIVE

To assess differences in small-for-gestational age (SGA) classifications for the detection of neonates with increased perinatal mortality risk among obese women and subsequently assess the association between prepregnancy body mass index (BMI) status and SGA.

DESIGN

Hospital-based cohort.

SETTING

Twelve US clinical centres (2002-08).

POPULATION

A total of 114 626 singleton, nonanomalous pregnancies.

METHODS

Data were collected using electronic medical record abstraction. Relative risks (RR) with 95% CI were estimated.

MAIN OUTCOME MEASURES

SGA trends (birthweight < 10th centile) classified using population-based (SGA_POP ), intrauterine (SGA_IU ) and customised (SGA_CUST ) references were assessed. The SGA-associated perinatal mortality risk was estimated among obese women. Using the SGA method most associated with perinatal mortality, the association between prepregnancy BMI and SGA was estimated.

RESULTS

The overall perinatal mortality prevalence was 0.55% and this increased significantly with increasing BMI (P < 0.01). Among obese women, SGA_IU detected the highest proportion of perinatal mortality cases (2.49%). Perinatal mortality was 5.32 times (95% CI 3.72-7.60) more likely among SGA_IU neonates than non-SGA_IU neonates. This is in comparison with the 3.71-fold (2.49-5.53) and 4.81-fold (3.41-6.80) increased risk observed when SGA_POP and SGA_CUST were used, respectively. Compared with women of normal weight, overweight women (RR = 0.82, 95% CI 0.78-0.86) and obese women (RR = 0.80; 95% CI 0.75-0.83) had a lower risk for delivering an SGA_IU neonate.

CONCLUSION

Among obese women, the intrauterine reference best identified neonates at risk of perinatal mortality. Based on SGA_IU , SGA is less common among obese women but these SGA babies are at a high risk of death and remain an important group for surveillance.

TWEETABLE ABSTRACT

SGA is less common among obese women but these SGA babies are at a high risk of death.

Effects of over-the-counter analgesic use on reproductive hormones and ovulation in healthy, premenopausal women

STUDY QUESTION

Does use of commonly used over-the-counter (OTC) pain medication affect reproductive hormones and ovulatory function in premenopausal women?

SUMMARY ANSWER

Few associations were found between analgesic medication use and reproductive hormones, but use during the follicular phase was associated with decreased odds of sporadic anovulation after adjusting for potential confounders.

WHAT IS KNOWN ALREADY

Analgesic medications are the most commonly used OTC drugs among women, but their potential effects on reproductive function are unclear.

STUDY DESIGN, SIZE, DURATION

The BioCycle Study was a prospective, observational cohort study (2005-2007) which followed 259 women for one (n = 9) or two (n = 250) menstrual cycles.

PARTICIPANTS, SETTING, METHODS

Two hundred and fifty-nine healthy, premenopausal women not using hormonal contraception and living in western New York state. Study visits took place at the University at Buffalo.

MAIN RESULTS AND THE ROLE OF CHANCE

During study participation, 68% (n = 175) of women indicated OTC analgesic use. Among users, 45% used ibuprofen, 33% acetaminophen, 10% aspirin and 10% naproxen. Analgesic use during the follicular phase was associated with decreased odds of sporadic anovulation after adjusting for age, race, body mass index, perceived stress level and alcohol consumption (OR 0.36 [0.17, 0.75]). Results remained unchanged after controlling for potential confounding by indication by adjusting for 'healthy' cycle indicators such as amount of blood loss and menstrual pain during the preceding menstruation. Moreover, luteal progesterone was higher (% difference = 14.0, -1.6-32.1, P = 0.08 adjusted) in cycles with follicular phase analgesic use, but no associations were observed with estradiol, LH or FSH.

LIMITATIONS, REASONS FOR CAUTION

Self-report daily diaries are not validated measures of medication usage, which could lead to some classification error of medication use. We were also limited in our evaluation of aspirin and naproxen which were used by few women.

WIDER IMPLICATIONS OF THE FINDINGS

The observed associations between follicular phase analgesic use and higher progesterone and a lower probability of sporadic anovulation indicate that OTC pain medication use is likely not harmful to reproduction function, and certain medications possibly improve ovulatory function.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract # HHSN275200403394C). The authors have no conflicts of interest to disclose.

Differences in risk factors for incident and recurrent small-for-gestational-age birthweight: a hospital-based cohort study

OBJECTIVE

Examine whether small-for-gestational-age (SGA) risk factors differed by prior SGA birth.

DESIGN

Hospital-based cohort study.

SETTING

Utah, USA.

POPULATION

Electronic medical record data from 25,241 women who were nulliparous at study entry with ≥2 subsequent consecutive singleton deliveries (2002-2010).

METHODS

Estimated adjusted relative risks (RR) and 95% confidence intervals (95% CI) for the association between second pregnancy characteristics and SGA risk. Tested for risk factor differences between recurrence and incidence (Pdifference).

MAIN OUTCOME MEASURES

Second pregnancy incident (n = 1067) and recurrent SGA (n = 484) determined using a population-based reference.

RESULTS

SGA complicated 20.3 and 4.5% of deliveries to women with and without a prior SGA birth, respectively. Young maternal age (Pdifference = 0.01) and pregnancy hypertensive diseases (Pdifference = 0.03) were associated with incident but not recurrent SGA. Significant risk factors for incidence and recurrence were smoking (incident RR = 1.64 [95% CI 1.22-2.19]; recurrent RR = 1.59 [95% CI 1.17-2.17]), short stature (incident RR = 1.34 [95% CI 1.16-1.54]; recurrent RR = 1.54 [95% CI 1.31-1.82]), prepregnancy underweight (incident RR = 1.32 [95% CI 1.07-1.64]; recurrent RR = 1.30 [95% CI 1.03-1.64]), and inadequate weight gain (incident RR = 1.41 [95% CI 1.22-1.64]; recurrent RR = 1.33 [95% CI 1.10-1.60]). Race-ethnicity, marital or insurance status, alcohol, diabetes, asthma, thyroid disease, depression, or interpregnancy interval were not associated with incidence or recurrence.

CONCLUSION

There was considerable overlap in the risk factors for SGA recurrence and incidence. Recurrence and incidence risk factors included smoking, short stature, underweight, and inadequate weight gain. Maternal age and hypertensive diseases increased the risk for incidence only. Regardless of the SGA definition, some potentially modifiable risk factors for recurrence were identified.