Menstrual irregularity as a biological limit to early pregnancy awareness

Menarche and Time to Cycle Regularity Among Individuals Born Between 1950 and 2005 in the US

Importance

Early menarche is associated with adverse health outcomes. Trends toward earlier menarche have been observed in the US, but data remain limited on differences by sociodemographic factors and body mass index (BMI). Time from menarche to cycle regularity is another understudied early-life characteristic with health implications.

Objectives

To evaluate the temporal trends and disparities in menarche and time to regularity and explore early-life BMI as a mediator.

Design, Setting, and Participants

This ongoing cohort study enrolled participants from an ongoing mobile application-based US cohort from November 14, 2019, to March 20, 2023.

Exposures

Birth year (categorized as 1950-1969, 1970-1979, 1980-1989, 1990-1999, and 2000-2005).

Main Outcomes and Measures

Main outcomes were age at menarche and time to regularity, which were self-recalled at enrollment. In addition, early (aged <11 years), very early (aged <9 years), and late (aged ≥16 years) age at menarche was assessed.

Results

Among the 71 341 female individuals who were analyzed (mean [SD] age at menarche, 12.2 [1.6] years; 2228 [3.1%] Asian, 3665 [5.1%] non-Hispanic Black, 4918 [6.9%] Hispanic, 49 518 [69.4%] non-Hispanic White, and 8461 [11.9%] other or multiple races or ethnicities), 5223 were born in 1950 to 1969, 12 226 in 1970 to 1979, 22 086 in 1980 to 1989, 23 894 in 1990 to 1999, and 7912 in 2000 to 2005. The mean (SD) age at menarche decreased from 12.5 (1.6) years in 1950 to 1969 to 11.9 (1.5) years in 2000 to 2005. The number of individuals experiencing early menarche increased from 449 (8.6%) to 1223 (15.5%), the number of individuals experiencing very early menarche increased from 31 (0.6%) to 110 (1.4%), and the number of individuals experiencing late menarche decreased from 286 (5.5%) to 137 (1.7%). For 61 932 participants with reported time to regularity, the number reaching regularity within 2 years decreased from 3463 (76.3%) to 4075 (56.0%), and the number not yet in regular cycles increased from 153 (3.4%) to 1375 (18.9%). The magnitude of the trend toward earlier menarche was greater among participants who self-identified as Asian, non-Hispanic Black, or other or multiple races (vs non-Hispanic White) (P = .003 for interaction) and among participants self-rated with low (vs high) socioeconomic status (P < .001 for interaction). Within a subset of 9865 participants with data on BMI at menarche, exploratory mediation analysis estimated that 46% (95% CI, 35%-61%) of the temporal trend in age at menarche was explained by BMI.

Conclusions and Relevance

In this cohort study of 71 341 individuals in the US, as birth year increased, mean age at menarche decreased and time to regularity increased. The trends were stronger among racial and ethnic minority groups and individuals of low self-rated socioeconomic status. These trends may contribute to the increase in adverse health outcomes and disparities in the US.

Abortion Provision and Delays to Care in a Clinic Network in Washington State After Dobbs

Importance

The Supreme Court decision Dobbs v Jackson Women's Health Organization (Dobbs) overturned federal protections to abortion care and altered the reproductive health care landscape. Thus far, aggregated state-level data reveal increases in the number of abortions in states where abortion is still legal, but there is limited information on delays to care and changes in the characteristics of people accessing abortion in these states after Dobbs.

Objective

To examine changes in abortion provision and delays to care after Dobbs.

Design, Setting, and Participants

Retrospective cohort study of all abortions performed at an independent, high-volume reproductive health care clinic network in Washington state from January 1, 2017, to July 31, 2023. Using an interrupted time series, the study assessed changes in abortion care after Dobbs.

Exposure

Abortion care obtained after (June 24, 2022, to July 31, 2023) vs before (January 1, 2017, to June 23, 2022) Dobbs.

Main Outcome and Measure

Primary outcomes included weekly number of abortions and out-of-state patients and weekly average of gestational duration (days) and time to appointment (days).

Results

Among the 18 379 abortions during the study period, most were procedural (13 192 abortions [72%]) and funded by public insurance (11 412 abortions [62%]). The mean (SD) age of individuals receiving abortion care was 28.5 (6.44) years. Following Dobbs, the number of procedural abortions per week increased by 6.35 (95% CI, 2.83-9.86), but then trended back toward pre-Dobbs levels. The number of out-of-state patients per week increased by 2 (95% CI, 1.1-3.6) and trends remained stable. The average gestational duration per week increased by 6.9 (95% CI, 3.6-10.2) days following Dobbs, primarily due to increased gestations of procedural abortions. The average gestational duration among out-of-state patients did not change following Dobbs, but it did increase by 6 days for in-state patients (5.9; 95% CI, 3.2-8.6 days). There were no significant changes in time to appointment.

Conclusions and Relevance

These findings provide a detailed picture of changes in abortion provision and delays to care after Dobbs in a state bordering a total ban state. In this study, more people traveled from out of state to receive care and in-state patients sought care a week later in gestation. These findings can inform interventions and policies to improve access for all seeking abortion care.

Irregular Cycles, Ovulatory Disorders, and Cardiometabolic Conditions in a US-Based Digital Cohort

Importance

Polycystic ovary syndrome (PCOS), characterized by irregular menstrual cycles and hyperandrogenism, is a common ovulatory disorder. Having an irregular cycle is a potential marker for cardiometabolic conditions, but data are limited on whether the associations differ by PCOS status or potential interventions.

Objective

To evaluate the association of PCOS, time to regularity since menarche (adolescence), and irregular cycles (adulthood) with cardiometabolic conditions.

Design, Setting, and Participants

This cross-sectional study used a large, US-based digital cohort of users of the Apple Research application on their iPhone. Eligibility criteria were having ever menstruated, living in the US, being at age of consent of at least 18 years (or 19 years in Alabama and Nebraska or 21 years in Puerto Rico), and being able to communicate in English. Participants were enrolled between November 14, 2019, and December 13, 2022, and completed relevant surveys.

Exposures

Self-reported PCOS diagnosis, prolonged time to regularity (not spontaneously establishing regularity within 5 years of menarche), and irregular cycles.

Main Outcomes and Measures

The primary outcome was self-reported cardiometabolic conditions, including obesity, prediabetes, type 1 and 2 diabetes, high cholesterol, hypertension, metabolic syndrome, arrhythmia, congestive heart failure, coronary artery disease, heart attack, heart valve disease, stroke, transient ischemic attack (TIA), deep vein thrombosis, and pulmonary embolism measured using descriptive statistics and logistic regression to estimate prevalence odds ratios (PORs) and 95% CIs. Effect modification by lifestyle factors was also estimated.

Results

The study sample (N = 60 789) had a mean (SD) age of 34.5 (11.1) years, with 12.3% having PCOS and 26.3% having prolonged time to regularity. Among a subset of 25 399 participants who completed the hormonal symptoms survey, 25.6% reported irregular cycles. In covariate-adjusted logistic regression models, PCOS was associated with a higher prevalence of all metabolic and several cardiovascular conditions, eg, arrhythmia (POR, 1.37; 95% CI, 1.20-1.55), coronary artery disease (POR, 2.92; 95% CI, 1.95-4.29), heart attack (POR, 1.79; 95% CI, 1.23-2.54), and stroke (POR, 1.66; 95% CI, 1.21-2.24). Among participants without PCOS, prolonged time to regularity was associated with type 2 diabetes (POR, 1.24; 95% CI, 1.05-1.46), hypertension (POR, 1.09; 95% CI, 1.01-1.19), arrhythmia (POR, 1.20; 95% CI, 1.06-1.35), and TIA (POR, 1.33; 95% CI, 1.01-1.73), and having irregular cycles was associated with type 2 diabetes (POR, 1.36; 95% CI, 1.08-1.69), high cholesterol (POR, 1.17; 95% CI, 1.05-1.30), arrhythmia (POR, 1.21; 95% CI, 1.02-1.43), and TIA (POR, 1.56; 95% CI, 1.06-2.26). Some of these associations were modified by high vs low body mass index or low vs high physical activity.

Conclusions and Relevance

These findings suggest that PCOS and irregular cycles may be independent markers for cardiometabolic conditions. Early screening and intervention among individuals with irregular menstrual cycles may be beneficial.

Job loss during pregnancy and the risk of miscarriage and stillbirth

STUDY QUESTION

Does the exposure to job loss during pregnancy increase the risk of miscarriage or stillbirth?

SUMMARY ANSWER

The experience of own or partner's job loss during the pregnancy is associated with an increased risk of miscarriageand stillbirth.

WHAT IS KNOWN ALREADY

Prior research on the psycho-social aspect of pregnancy loss has investigated the contextual and the individual-level stressors. At the contextual level, natural disasters, air pollution, and economic downturns are associated with higher risk of pregnancy loss. At the individual level, intense working schedules and financial strain are linked with increased risk of pregnancy loss both at early and later stages of the gestation.

STUDY DESIGN, SIZE, DURATION

This work draws on high-quality individual data of 'Understanding Society', a longitudinal survey that has interviewed a representative sample of households living in the UK annually since 2009. Approximately 40 000 households were recruited. The analyses use all the available survey waves (1-12, 2009-2022).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The final sample consisted of 8142 pregnancy episodes that contain complete informationon pregnancy outcome and date of conception. Ongoing pregnancies at the time of the interview were excluded from the final sample. The outcome variable indicated whether a pregnancy resulted in a live birth or a pregnancy loss whereas the exposure variable identified the women's or their partner's job loss because of redundancy or a dismissal. Logistic regression models were employed to estimate the relation between job loss during pregnancy and pregnancy loss. The models were adjusted for an array of socio-demographic and economic characteristics following a stepwise approach. Several sensitivity analyses complemented the main findings.

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline models controlling for women's demographic background and prior experience of miscarriage estimated an increased risk of pregnancy loss when women were exposed to their own or their partner's job loss during their pregnancy (odds ratio (OR) = 1.99, 95% CI: 1.32, 2.99). When the models were adjusted for all socio-economic and partnership-related covariates the association remained robust (OR = 1.81, 95% CI: 1.20, 2.73).

LIMITATIONS, REASONS FOR CAUTION

First, the pregnancy outcome and the date of conception were self-reported and may besubjected to recall and social desirability bias. Second, although we adjusted for an array socio-demographic characteristics and self-reported health, other contextual factors might be correlated with both job loss and pregnancy loss. Third, owing to the limited sample size, we could not assess if the main finding holds across different socio-economic strata.

WIDER IMPLICATIONS OF THE FINDINGS

By showing that exposure to a job loss during pregnancy increases the risk of miscarriage and stillbirth, we underline the relevance of pregnancy loss as a preventable public health matter. This result also calls for policy designthat enhances labour market protection and social security buffers for pregnant women and their partners.

STUDY FUNDING/COMPETING INTERESTS

The authors received the following financial support for the research, authorship, and/or publication of this article: H2020 Excellent Science, H2020 European Research Council, Grant/Award Number: 694262 (project DisCont-Discontinuities in Household and Family Formation) and the Economic and Social Research Centre on Micro-Social Change (MiSoC). There are no conflicts of interest to declare.

The Impact of Irregular Menstruation on Health: A Review of the Literature

Women are considered to have an irregular menstrual cycle if their cycle length is less than 21 days or more than 35 days, accompanied by less or very severe blood flow. The prevalence of menstrual cycle irregularities varies across countries. Irregular periods can occur due to changes in the body's levels of estrogen and progesterone hormones, which disrupt the normal pattern of the period. Menstrual irregularity has been found to be associated with various diseases and medical conditions, such as metabolic syndrome, coronary heart disease, type 2 diabetes mellitus, and rheumatoid arthritis. Anemia, osteoporosis, psychological problems, impaired quality of life, and infertility have also been recorded. Moreover, a significant correlation between irregular periods and the risk of developing pregnancy-related hypertensive disorders, as well as an increased risk of adverse obstetric and neonatal outcomes, has been proven. Therefore, irregular menstruation is considered an important health indicator among women. Physical, mental, social, psychological, and reproductive problems are often associated with menstrual irregularities. Thus, evaluating the factors associated with irregular menstruation is necessary to determine appropriate preventive and treatment strategies and to decrease the associated health problems. The aim of this review was to define normal and irregular menstruation, their types, and prevalence, to recognize the risk factors and causes of irregular menstruation, and to understand their impact on women's health.

Demography as a Field: Where We Came From and Where We Are Headed

This essay provides a series of reflections on the current state of demography as seen by four early-career researchers who are actively engaged in aspects of the discipline as varied as research, teaching, mentorship, data collection efforts, policy making, and policy advising. Despite some claims that the discipline is weakening, we showcase the great potential of the field and outline promising pathways and novel directions for the future. In so doing, we critically assess recent innovations in data quality and availability, stressing the need to "revolutionize" the way that demographic methods are taught by adopting a viewpoint that more closely reflects the rapidly changing, or "fast," nature of global social phenomena such as conflict-related displacements, environmental disasters, migration streams, pandemics, and evolving population policies. We conclude by discussing the relevance of careful demographic analyses for policy making, stressing three main points: (i) the need to make demography more visible and understandable to the public eye; (ii) the importance of engaging and co-creating with local communities to "break" the academic bubble; and (iii) the urge to counteract the spread of misinformation-a phenomenon that has become even more visible in the aftermath of the COVID-19 outbreak.

Menstrual cycle length variation by demographic characteristics from the Apple Women's Health Study

Menstrual characteristics are important signs of women's health. Here we examine the variation of menstrual cycle length by age, ethnicity, and body weight using 165,668 cycles from 12,608 participants in the US using mobile menstrual tracking apps. After adjusting for all covariates, mean menstrual cycle length is shorter with older age across all age groups until age 50 and then became longer for those age 50 and older. Menstrual cycles are on average 1.6 (95%CI: 1.2, 2.0) days longer for Asian and 0.7 (95%CI: 0.4, 1.0) days longer for Hispanic participants compared to white non-Hispanic participants. Participants with BMI ≥ 40 kg/m² have 1.5 (95%CI: 1.2, 1.8) days longer cycles compared to those with BMI between 18.5 and 25 kg/m². Cycle variability is the lowest among participants aged 35-39 but are considerably higher by 46% (95%CI: 43%, 48%) and 45% (95%CI: 41%, 49%) among those aged under 20 and between 45-49. Cycle variability increase by 200% (95%CI: 191%, 210%) among those aged above 50 compared to those in the 35-39 age group. Compared to white participants, those who are Asian and Hispanic have larger cycle variability. Participants with obesity also have higher cycle variability. Here we confirm previous observations of changes in menstrual cycle pattern with age across reproductive life span and report new evidence on the differences of menstrual variation by ethnicity and obesity status. Future studies should explore the underlying determinants of the variation in menstrual characteristics.

Estimation of Multiyear Consequences for Abortion Access in Georgia Under a Law Limiting Abortion to Early Pregnancy

Importance

Following the US Supreme Court ruling in Dobbs v Jackson Women's Health Organization, Georgia's law limiting abortion to early pregnancy, House Bill 481 (HB481), was allowed to go into effect in July 2022.

Objectives

To estimate anticipated multiyear effects of HB481, which prohibits abortions after detection of embryonic cardiac activity, on abortion incidence in Georgia, and to examine inequities by race, age, and socioeconomic status.

Design, Setting, and Participants

This repeated cross-sectional analysis used abortion surveillance data from January 1, 2007, to December 31, 2017, to estimate future effects of HB481 on abortion care in Georgia, with a focus on the 2 most recent years of data (2016 and 2017). Abortion surveillance data were obtained from the 2007-2017 Georgia Department of Public Health's Induced Termination of Pregnancy files. Linear regression was used to estimate trends in abortions provided at less than 6 weeks' gestation and at 6 weeks' gestation or later in Georgia, and χ2 analyses were used to compare group differences by race, age, and educational attainment. Data were analyzed from July 26 to September 22, 2022.

Exposures

HB481, Georgia's law limiting abortion to early pregnancy.

Main Outcome and Measures

Weeks' gestation at abortion (<6 vs ≥6 weeks).

Results

From January 1, 2007, to December 31, 2017, there were 360 972 reported abortions in Georgia, with an annual mean (SD) of 32 816 (1812) abortions. Estimates from 2016 to 2017 suggest that 3854 abortions in Georgia (11.6%) would likely meet eligibility requirements for abortion care under HB481. Fewer abortions obtained by Black patients (1943 [9.6%] vs 1280 [16.2%] for White patients), patients younger than 20 years (261 [9.1%] vs 168 [15.0%] for those 40 years and older), and patients with fewer years of education (392 [9.2%] with less than a high school diploma and 1065 [9.6%] with a high school diploma vs 2395 [13.5%] for those with some college) would likely meet eligibility requirements under HB481.

Conclusions and Relevance

These findings suggest that Georgia's law limiting abortion to early pregnancy (HB481) would eliminate access to abortion for nearly 90% of patients in Georgia, and disproportionately harm patients who are Black, younger, and in lower socioeconomic status groups.

Abnormal uterine bleeding patterns determined through menstrual tracking among participants in the Apple Women's Health Study

BACKGROUND

Use of menstrual tracking data to understand abnormal bleeding patterns has been limited because of lack of incorporation of key demographic and health characteristics and confirmation of menstrual tracking accuracy.

OBJECTIVE

This study aimed to identify abnormal uterine bleeding patterns and their prevalence and confirm existing and expected associations between abnormal uterine bleeding patterns, demographics, and medical conditions.

STUDY DESIGN

Apple Women's Health Study participants from November 2019 through July 2021 who contributed menstrual tracking data and did not report pregnancy, lactation, use of hormones, or menopause were included in the analysis. Four abnormal uterine bleeding patterns were evaluated: irregular menses, infrequent menses, prolonged menses, and irregular intermenstrual bleeding (spotting). Monthly tracking confirmation using survey responses was used to exclude inaccurate or incomplete digital records. We investigated the prevalence of abnormal uterine bleeding stratified by demographic characteristics and used logistic regression to evaluate the relationship of abnormal uterine bleeding to a number of self-reported medical conditions.

RESULTS

There were 18,875 participants who met inclusion criteria, with a mean age of 33 (standard deviation, 8.2) years, mean body mass index of 29.3 (standard deviation, 8.0), and with 68.9% (95% confidence interval, 68.2-69.5) identifying as White, non-Hispanic. Abnormal uterine bleeding was found in 16.4% of participants (n=3103; 95% confidence interval, 15.9-17.0) after accurate tracking was confirmed; 2.9% had irregular menses (95% confidence interval, 2.7-3.1), 8.4% had infrequent menses (95% confidence interval, 8.0-8.8), 2.3% had prolonged menses (95% confidence interval, 2.1-2.5), and 6.1% had spotting (95% confidence interval, 5.7-6.4). Black participants had 33% higher prevalence (prevalence ratio, 1.33; 95% confidence interval, 1.09-1.61) of infrequent menses compared with White, non-Hispanic participants after controlling for age and body mass index. The prevalence of infrequent menses was increased in class 1, 2, and 3 obesity (class 1: body mass index, 30-34.9; prevalence ratio, 1.31; 95% confidence interval, 1.13-1.52; class 2: body mass index, 35-39.9; prevalence ratio, 1.25; 95% confidence interval, 1.05-1.49; class 3: body mass index, >40; prevalence ratio, 1.51; 95% confidence interval, 1.21-1.88) after controlling for age and race/ethnicity. Those with class 3 obesity had 18% higher prevalence of abnormal uterine bleeding compared with healthy-weight participants (prevalence ratio, 1.18; 95% confidence interval, 1.02-1.38). Participants with polycystic ovary syndrome had 19% higher prevalence of abnormal uterine bleeding compared with participants without this condition (prevalence ratio, 1.19; 95% confidence interval, 1.08-1.31). Participants with hyperthyroidism (prevalence ratio, 1.34; 95% confidence interval, 1.13-1.59) and hypothyroidism (prevalence ratio, 1.17; 95% confidence interval, 1.05-1.31) had a higher prevalence of abnormal uterine bleeding, as did those reporting endometriosis (prevalence ratio, 1.28; 95% confidence interval, 1.12-1.45), cervical dysplasia (prevalence ratio, 1.20; 95% confidence interval, 1.03-1.39), and fibroids (prevalence ratio, 1.14; 95% confidence interval, 1.00-1.30).

CONCLUSION

In this cohort, abnormal uterine bleeding was present in 16.4% of those with confirmed menstrual tracking. Black or obese participants had increased prevalence of abnormal uterine bleeding. Participants reporting conditions such as polycystic ovary syndrome, thyroid disease, endometriosis, and cervical dysplasia had a higher prevalence of abnormal uterine bleeding.

Association of Texas' 2021 Ban on Abortion in Early Pregnancy With the Number of Facility-Based Abortions in Texas and Surrounding States

IMPORTANCE

Texas' 2021 ban on abortion in early pregnancy may demonstrate how patterns of abortion might change following the US Supreme Court's June 2022 decision overturning Roe v Wade.

OBJECTIVE

To assess changes in the number of abortions and changes in the percentage of out-of-state abortions among Texas residents performed at 12 or more weeks of gestation in the first 6 months following implementation of Texas Senate Bill 8 (SB 8), which prohibited abortions after detection of embryonic cardiac activity.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective study of a sample of 50 Texas and out-of-state abortion facilities using an interrupted time series analysis to assess changes in the number of abortions, and Poisson regression to assess changes in abortions at 12 or more weeks of gestation. Data included 68 820 Texas facility-based abortions and 11 287 out-of-state abortions among Texas residents during the study period from September 1, 2020, to February 28, 2022.

EXPOSURES

Abortion care obtained after (September 2021-February 2022) vs before (September 2020-August 2021) implementation of SB 8.

MAIN OUTCOMES AND MEASURES

Primary outcomes were changes in the number of facility-based abortions for Texas residents, in Texas and out of state, in the month after implementation of SB 8 compared with the month before. The secondary outcome was the change in the percentage of out-of-state abortions among Texas residents obtained at 12 or more weeks of gestation during the 6-month period after the law's implementation.

RESULTS

Between September 2020 and August 2021, there were 55 018 abortions in Texas and 2547 out-of-state abortions among Texas residents. During the 6 months after SB 8, there were 13 802 abortions in Texas and 8740 out-of-state abortions among Texas residents. Compared with the month before implementation of SB 8, the number of Texas facility-based abortions significantly decreased from 5451 to 2169 (difference, -3282 [95% CI, -3171 to -3396]; incidence rate ratio [IRR], 0.43 [95% CI, 0.36-0.51]) in the month after SB 8 was implemented. The number of out-of-state abortions among Texas residents significantly increased from 222 to 1332 (difference, 1110 [95% CI, 1047-1177]; IRR, 5.38 [95% CI, 4.19-6.91]). Overall, the total documented number of Texas facility-based and out-of-state abortions among Texas residents significantly decreased from 5673 to 3501 (absolute change, -2172 [95% CI, -2083 to -2265]; IRR, 0.67 [95% CI, 0.56-0.79]) in the first month after SB 8 was implemented compared with the previous month. Out-of-state abortions among Texas residents obtained at 12 or more weeks of gestation increased from 17.1% (221/1291) to 31.0% (399/1289) (difference, 178 [95% CI, 153-206]) during the period between September 2021 and February 2022 (P < .001 for trend).

CONCLUSIONS AND RELEVANCE

Among a sample of abortion facilities, the 2021 Texas law banning abortion in early pregnancy (SB 8) was significantly associated with a decrease in the documented total of facility-based abortions in Texas and obtained by Texas residents in surrounding states in the first month after implementation compared with the previous month. Over the 6 months following SB 8 implementation, the percentage of out-of-state abortions among Texas residents obtained at 12 or more weeks of gestation significantly increased.