Longitudinal changes in sexual desire and attraction among women who started using the Natural Cycles app

Many women experience sexual side effects, such as decreased libido, when taking hormonal contraceptives (HCs). However, little is known about the extent to which libido recovers after discontinuing HCs, nor about the timeframe in which recovery is expected to occur. Given that HCs suppress the activities of multiple endogenous hormones that regulate both the ovulatory cycle and women's sexual function, resumption of cycles should predict libido recovery. Here, using a combination of repeated and retrospective measures, we examined changes in sexual desire and partner attraction (among partnered women) across a three-month period in a sample of Natural Cycles users (Survey 1: n = 1596; Survey 2: n = 550) who recently discontinued HCs. We also tested whether changes in these outcomes coincided with resumption of the ovulatory cycle and whether they were associated with additional factors related to HC use (e.g., duration of HC use) or relationship characteristics (e.g., relationship length). Results revealed that both sexual desire and partner attraction, on average, increased across three months after beginning to use Natural Cycles. While the prediction that changes in sexual desire would co-occur with cycle resumption was supported, there was also evidence that libido continued to increase even after cycles resumed. Together, these results offer new insights into relationships between HC discontinuation and women's sexual psychology and lay the groundwork for future research exploring the mechanisms underlying these effects.

A multi-site study of the relationship between photoperiod and ovulation rate using Natural Cycles data

Many species exhibit seasonal patterns of breeding. Although humans can shield themselves from many season-related stressors, they appear to exhibit seasonal patterns of investment in reproductive function nonetheless, with levels of sex steroid hormones being highest during the spring and summer months. The current research builds on this work, examining the relationship between day length and ovarian function in two large samples of women using data from the Natural Cycles birth control application in each Sweden and the United States. We hypothesized that longer days would predict higher ovulation rates and sexual motivation. Results revealed that increasing day length duration predicts increased ovulation rate and sexual behavior, even while controlling for other relevant factors. Results suggest that day length may contribute to observed variance in women's ovarian function and sexual desire.

P-631 Day Length Predicts Ovulatory Shifts in Women’s Reproductive Function

Study question

Is there a relationship between day length and ovulation rate in women of reproductive age?

Summary answer

Analysis showed that increasing day length is associated with higher ovulation rate in women of reproductive age in both Sweden and the United States (US).

What is known already

Historically, winter months have been characterised by threatening survival conditions, such as reduced food availability and lower temperatures. Day length, or photoperiod, provides a reliable indication of upcoming seasonal changes, which promotes season-specific adaptations to behaviours and reproductive systems in mammals. To avoid the survival threats the winter months present, mammals with long gestation periods typically exhibit increased breeding as photoperiods increase. As humans also possess long gestation periods, it may be that humans similarly adapt to increasing photoperiods by exhibiting seasonal shifts in reproductive functioning.

Study design, size, duration

This retrospective analysis of basal body temperature (BBT) data from the Natural Cycles contraceptive app included approximately 115,000 Natural Cycles users’ data, amounting to approximately 1.3 million cycles from May 2014 - January 2021. BBT was used to confirm ovulation, the rate of which was calculated and compared to the number of hours daylight users experienced based on the geographical location in which they had registered for the app.

Participants/materials, setting, methods

We exclude cycles with missing data for any of the studied variables leaving ∼180k Swedish and ∼150K US cycles. The Meteostat library supplied the temperature on the start date of each user cycle. The Suntime library was used to determine the number of hours of daylight users were exposed to on the start date of each cycle, which used the geographic coordinates of the users’ reported country of residence.

Main results and the role of chance

Menstrual Cycle data from approximately 115 thousand Natural Cycles app users aged between 18-62 from two geographic groups, Sweden and the US. Data from cycles during and immediately following the event of a miscarriage, pregnancy, or instance of taking an emergency contraceptive, as well as the two cycles immediately following a completed pregnancy. Using a generalised logistic mixed-effects model, implementation via GPBoost, user-specific variation in ovulation rate as a function of location-specific day length was assessed while controlling for age, cycle length, body mass index (BMI), daily temperature, and education level. We find that day length is significantly correlated with higher ovulation (p < 0.01) in both the US and Swedish cohort.

Limitations, reasons for caution

Ovulation rate and day length may have emerged as a function a several underlying mechanisms, including the optimisation of conditions for childbirth, the optimisation of conditions for conception and early embryonic development, or a decrease in ovulation during the darker, winter months as a result of investment in immune function.

Wider implications of the findings

Photoperiod may be an important regulator of human reproductive activity, providing some preliminary evidence of seasonal changes to women’s ovulatory functioning. Furthermore, birth rate as a measurement of seasonal reproductive patterns in humans may not be as stable or accurate a measure for contemporary analyses of women’s reproductive functioning.

Trial registration number

000000

Quality of life in lower limb amputees: a cross-sectional study from a tertiary care center of South India

BACKGROUND

Various literature have dealt with the physical aspect of amputation and the functional outcome after amputation. There are a few studies that give focused attention to the quality of life (QOL) of amputees. These studies are mostly from the developed countries. This study analyzed amputation as a whole and how it affects an individual physically, psychologically, emotionally, and socially, which would enable the health care providers to help the amputees to attain a better QOL.

STUDY DESIGN

Cross-sectional study.

MATERIALS AND METHODS

This cross-sectional study was conducted on lower limb amputees. Data were collected using a proforma for demographic details and two pretested questionnaires-the World Health Organization QOL-Bref and prostheses-specific Trinity Amputation and Prosthesis Experience Scales-Revised questionnaires. The data were analyzed using SPSS software, version 20.

RESULTS

Amputation significantly affects all domains of the QOL. Age was a significant determinant of QOL of amputees, and it was found that the QOL decreased with an increase in age. 48.1% of the amputees were using a prosthetic device, and they were found to have a significantly better QOL. The prevalence of residual limb pain and phantom limb pain was 52.9% and 37%, respectively.

CONCLUSION

Nearly half of the population perceived that their QOL was neither poor nor good. The QOL of the physical domain was better than the other domains. The most important factors that were found to be associated with QOL of amputees were age, duration since amputation, and use of prosthesis.

Medullary carcinoma of thyroid metastasis to breast: A cytological experience

Medullary carcinoma of thyroid is a relatively uncommon malignancy, which can be sporadic and syndromic in nature. It commonly spreads to regional lymph nodes followed by spreading to distant sites. Breast is an uncommon site of metastasis of this malignancy. Our case is a 38-year-old woman married parous woman presenting to the outpatient department with complaints of lump in both the breasts. Fine-needle aspiration (FNA) was attempted, which revealed a malignancy more suggestive of a metastasis, which was confirmed on CT scan. A detailed history revealed that the patient is a known case of medullary carcinoma of thyroid. The report was given as metastatic medullary carcinoma to the breast after confirming with a calcitonin immunostain. Given the versatility of primary lesions in the breast, minimally invasive FNA cytology (FNAC) technique with adequate sampling helps in identifying metastatic lesions. Differentiating primary from metastatic lesions changes the course of management to the patient. Metastatic lesions should always be kept in mind in the occurrence of known malignancies, however rare the site of occurrence may be. Morphological clues and immunohistochemical work up aid in arriving at correct diagnosis.