Emergency contraceptive pill use among women in Denmark, Norway and Sweden: Population‐based survey

Assessing the association between age at first sexual intercourse and migraine: a Mendelian randomization study

Background and objectives

As indicated by observational and genetic variation studies, age at first sexual intercourse (AFS) may be associated with migraine attack, but there is a lack of evidence from real-world studies due to ethical concerns. Therefore, we conducted a Mendelian randomization study to determine the causal relationship between AFS and migraine.

Methods

We extracted instrumental variables from summary data of a genome-wide association study (GWAS) on AFS and migraine and then conducted two-sample Mendelian randomization analyses. GWAS data for AFS and migraine were obtained from 397,338 unrelated individuals (214,547 females and 182,791 males) and 306,314 individuals (18,477 patients and 287,837 control individuals), respectively.

Results

There was a causal relationship between AFS and risk for migraine (odds ratio (OR) = 0.73, 95% confidence interval (CI) [0.61 to 0.86]), both for migraine with aura (MWA; OR = 0.72, 95% CI [0.58 to 0.89]) and migraine without aura (MOA; OR = 0.66, 95% CI [0.51 to 0.86]). Stratified analyses provided suggestive evidence of the causal relationship between delayed AFS and a decreased risk of migraine for both males (OR = 0.71, 95% CI [0.59 to 0.84]) and females (OR = 0.73, 95% CI [0.61 to 0.89]). Reverse Mendelian randomization did not reveal any effect of migraine on AFS (p > 0.05). No pleiotropy was detected.

Discussion

A delayed AFS is a protective factor against migraine (for both MWA and MOA) in both males and females. This causal relationship indicates the presence of extracranial regulatory pathways of migraine.

The emergency contraceptive pill in Brazil: High usage rates but schooling differences persist

OBJECTIVES

This paper aims to analyze usage rates for the emergency contraceptive pill (ECP) among women living in the city of São Paulo and their associated factors.

STUDY DESIGN

A population based cross-sectional survey was conducted in 2015 with a probabilistic sample of 4,000 women aged 15 to 44 living in São Paulo, Brazil. Response rate for households was 75% and 77% for eligible women. Binary logistic regression models were used to describe the association between each outcome and selected variables.

RESULTS

A total of 51.4% of women living in the city of São Paulo had used ECP at least once in their lifetime. Women under 35 were more likely to use ECP, as were those with more than 9 years of schooling, having at least one live birth, not cohabiting with a partner, with more than two lifetime sexual partners and as length of sexual life decreased. Among ECP users, 32.6% used it only once, 47.5% used it 2 to 4 times, and 19.9% used it 5 or more times.

CONCLUSIONS

Our findings suggest that ECPs have been incorporated into the contraceptive method mix for many women as a fundamental strategy for regulating fertility. Particularly young women, unmarried women and those who have had more partners seem to take greater advantage of ECP to prevent pregnancy.

IMPLICATIONS

Despite the high use rate, lower levels of schooling are associated with lower levels of ECP use. There is a need for both policies to reduce schooling inequities and strategies to improve women's knowledge of reproduction and contraception.