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  • Writer's pictureDoctors for Choice

Morning After Pills do not impair implantation: Here are 6 scientific studies to prove it.

It is frequently claimed that morning after pills (emergency contraception) could impair the implantation of a fertilised egg in the womb. People who adhere strictly to the "life begins at conception" ideology claim this is tantamount to abortion, even though in medical terms pregnancy is usually considered to begin at implantation.

The alleged inhibition of implantation by morning after pills is the reason why certain professionals in Malta refuse to supply these medications, to the detriment of women seeking emergency contraception. This may paradoxically lead to more unwanted pregnancies and more terminations of pregnancy.

There is no reliable scientific evidence that suggests morning after pills impair implantation. In fact, the American College of Obstetricians and Gynaecologists has stated that "review of the evidence suggests that emergency contraception is unlikely to prevent implantation of a fertilized egg." Here are 6 studies which have provided scientific evidence that morning after pills do not impair implantation:

"Peri- and post-ovulatory administration of LNG (levonorgestrel) did not impair corpus luteum function or endometrial morphology."

"The findings indicate that the contraceptive effect of postcoital treatment with EE/LNG and danazol is mainly due to an inhibition or delay of ovulation... The direct effect on the endometrium is limited, if any."

"LNG-EC has no effect on endometrial development or function. In an in vitro model, it was demonstrated that LNG did not interfere with blastocyst function or implantation."

"LNG inhibited ovulation totally or partially [in rats], depending on the timing of treatment and/or total dose administered, whereas it had no effect on fertilization or implantation when it was administered shortly before or after mating, or before implantation."

"In Cebus monkeys, LNG can inhibit or delay ovulation but, once fertilization has taken place, it cannot prevent the establishment of pregnancy. These findings do not support the hypothesis that emergency contraception with LNG prevents pregnancy by interfering with post-fertilization events."

"There is no apparent change in the level of these two integrins in the human endometrium when high-dose oral contraceptives are given in the later stages of the implantation window."


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