Abstract | North American Regional Virtual Conference for Restorative Reproductive Medicine

 

July 22, 2020

Najmabadi S.1 Stanford JB.1

s.najmabadi@utah.edu
Shahpar Najmabadi

1 Office of Cooperative Reproductive Health, Division of Public Health, Department of Family and Preventive Medicine, University of Utah, Salt Lake City, Utah, USA 
Author Affiliations

Title: Recent use of oral contraceptives and menstrual cycle characteristics

Background:
Oral contraceptives (OC) are the most common temporary contraception used in the USA. We assessed menstrual cycle characteristics in relation to recent use of OC.

Methods:
We studied 3,096 menstrual cycles of 521 women with no known subfertility, who were followed for up to 1 year. Women recorded vaginal bleeding or cervical mucus discharge daily. We used the peak day of cervical mucus as the estimated day of ovulation and the last day of the follicular phase. We used generalized linear mixed models to describe menstrual cycle parameters among 191 recent OC users (OCU) (1,067 cycles) who discontinued OC within the year before joining the study, compared to 330 women (2,029 cycles) who did not use OC (NOC).

Results:
Majority of women were 35 days 1.52, CI: 1.03, 2.23]; longer follicular phase [20.3 days, CI: 19.3, 21.2 vs 18.1 days, CI: 17.4, 18.8, OR follicular phase >21 days 1.75, CI: 1.32, 2.32]; shorter luteal phase (11.1 days, CI: 10.7, 11.5 vs 11.8 days, CI: 11.5, 12.1, OR luteal phase <8 days 2.43, CI 1.69, 3.50]; shorter menses [6.1 days, CI: 5.9, 6.3 vs 6.4 days, CI: 6.2, 6.5]; and lower mucus quality [7.6, CI: 7.0, 8.1 vs 8.7, CI: 8.4, 9.1]. Women who discontinued pills within 60 days prior to the study compared to those who discontinued pills earlier had the most deviation from cycle parameters of NOCs.

Conclusions: Our findings indicate reduced fecundability for some months after discontinuation of pills. The time needed to gain normal menstrual function needs further assessment.