BALTIMORE -- Projections notwithstanding, easy access to so-called morning-after pills does not reduce population-level pregnancy rates, according to a meta-analysis.
BALTIMORE, April 18 -- Projections notwithstanding, easy access to so-called morning-after pills does not reduce population-level pregnancy rates, according to a meta-analysis.
None of the eight studies included found a difference in pregnancy rates between women who kept emergency contraception on hand and those with standard access, found Chelsea Polis, a Ph.D. candidate at Johns Hopkins Bloomberg School of Public Health here, and colleagues.
However, advance access did not decrease use of condoms or other contraceptives, they reported in The Cochrane Library.
"Conclusions about population level effects should not impede efforts to ensure all women have access to emergency contraception when they need it," the researchers cautioned.
"Women should be given information on and easy access to emergency contraception because individual women can decrease their chances of pregnancy by using the method," they added.
While emergency contraception--a relatively high dose of ordinary birth control hormones--is effective in preventing pregnancy when taken within three to five days after unprotected sex, many women reportedly have difficulty obtaining the pills when needed.
"Even under ideal circumstances, obtaining a prescription within 72 hours can be difficult," the researchers wrote.
So some countries have allowed emergency contraception to be sold over the counter. In August 2006, the FDA announced that one brand of levonorgestrel, Plan B, could be sold without a prescription from behind the counter to women 18 or older.
The meta-analysis primarily included studies using levonorgestrel alone (five studies). Two studies used an estrogen-progestin combination (called the Yuzpe regimen) and one used mifepristone (Mifeprex), which is FDA approved only for medical abortion of intrauterine pregnancy.
The eight studies compared these medications provided in advance of need with a control group that had standard access, which may have included a discussion of emergency contraception, or provision of emergency contraception on request at a clinic or pharmacy.
Most of the 6,389 patients included were in the United States though four studies were conducted in China and India. The intervention groups received one to three courses of emergency in advance with provisions for women to obtain additional courses. Follow up ranged from three to 12 months.
Four studies focused on younger women, one focused on adolescent mothers, and two primarily enrolled postpartum women. Women were recruited from family planning clinics or hospitals, and in one case from case management services for adolescent mothers.
None of the studies found that advance access significantly improved pregnancy rates, including two studies that were adequately powered to detect a difference.
Comparing the advance and standard access groups, the findings were:
This lack of effect was despite significantly increased use of morning-after pills overall among women with advance access (single use OR 2.52; 95% CI 1.72 to 3.70, and multiple use OR 4.13, 95% CI 1.77 to 9.63). Three studies also showed that these women were more likely to use emergency contraception at least twice (OR 4.13, 95% CI 1.77 to 9.63).
Furthermore, as expected, women with advance access used the pills sooner after unprotected sex compared with those who had only standard access (weighted mean difference -14.6 hours, 95% CI -16.77 to -12.4 hours).
While concerns had circulated that easy access to morning after pills would promote negative sexual behaviors, the meta-analysis showed no effect from advance access.
In the three studies that looked at sexually transmitted infection rates, there were essentially identical rates between groups (OR 0.99, 95% CI 0.73 to 1.34).
Nor was there an increase in the frequency of unprotected sex. One study showed that 26% of participants in both groups had unprotected intercourse in the prior month at the six month follow-up. Two studies showed that women in the control group were less likely to report using emergency contraception when they did have unprotected sex.
The five studies to look at changes in contraceptive use showed that advance provision of morning after pills did not encourage adoption of less reliable methods. Likewise, the six studies to look at condom use found no difference at 12 months (OR 1.01, 95% CI 0.87 to 1.16) or at six months (OR 0.94, 95% CI 0.66 to 1.34).
A sensitivity analysis found similar results for the outcomes irrespective of whether studies that lost more than 20% of patients to follow-up were included.
"Advance provision does not negatively impact sexual and reproductive health behaviors and outcomes," the researchers concluded. "Women should have easy access to emergency contraception, because it can decrease the chance of pregnancy" on the individual level despite no effect at the population level.