Evidence from literature that some forms of the Pill likely act as an abortifacient:
YASMIN is a monophasic, combination oral contraceptive that contains the active ingredients drospirenone and ethinyl estradiol. Combination oral contraceptives act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increases the difficulty of sperm entry into the uterus) and the endometrium (which reduces the likelihood of implantation).1
The number after the product name indicates how many pills are in a blister pack. For Yasmin 21 a blister pack contains “21 hormone-containing yellow, film-coated, round tablets.”2 while for Yasmin 28 a blister pack contains “21 hormone-containing yellow and 7 hormone-free white, film-coated, round tablets.”3
These white tablets are placebos (Here COC is an acrynym for “combined oral contraceptive”):
Early COCs relied on a 21/7 dosing regimen in which each monthly pill pack would include twenty-one active pills containing synthetic progestin and estrogen followed by seven placebo pills containing no hormones. The seven-day placebo period, also known as the pill-free interval, was originally included because it (i) triggered a “withdrawal bleed” that mimicked natural menstrual bleeding and was presumed to improve acceptance among COC users, and (ii) provided a regular break from synthetic hormone exposure that was thought to mitigate potential side effects. The 21/7 regimen persists in most COCs on the market today.4
More on withdrawl bleeds at healthline
This document goes on further to state:
In the early 1990s, Bayer began developing a low-dose COC containing 20 μg EE and the synthetic progestin drospirenone (“DRSP”) to be administered with a reduced pill-free interval. Lowering EE dosage to 20 μg per pill limits undesirable side effects, but it also results in weaker ovarian suppression compared to higher-dose COCs. As such, some ovarian activity and follicular maturation can persist in users of low-dose COCs, and any intake errors (i.e., missed pills), especially those that effectively lengthen the unregulated pill-free interval, could result in “escape” ovulation and unintended pregnancy…To address the risk of escape ovulation for users of low-dose COCs, Bayer implemented 23/5 and 24/4 dosing regimens, reducing the pill-free interval to five or four days, respectively, and increasing the number of active pills per cycle accordingly Bayer demonstrated that shortening the pill-free interval to four or five days improved the contraceptive efficacy of low-dose COC formulations.5 (Emphasis mine)
This demonstrates the issue with low dose COCs causing escape ovulation, unintended pregnancy or abortion, particularly if there are intake errors. Nor is it clear if COCs using 23/5 or 24/4 dosing regimens eliminates this problem.
A study from the University of Saskatchewan by Angela R. Baerwald, et al, pulished June 7, 2009, titled “Effects of oral contraceptives administered at defined stages of ovarian follicular development“6 Detailed the effects of the timing of when a woman begins taking oral contraception (OC) on whether or not ovulation occurs (full development release of an egg from one of the ovaries). Forty-five women were enrolled in the study and “Women were required to have been off hormonal contraceptives for at least 1 month before taking part in the study.” Furthermore:
Women were randomly assigned to initiate OC use when a follicle diameter of either 10۫ ± 1 mm (n = 16), [“n = 16” meaning 16 women] 14 ± 1 mm (n = 14), or 18 ± 1 mm (n = 15), was detected after menses. All women were administered an OC containing 150 μg of desogestrel plus 30 μg of ethinyl E2 daily for one complete dosing cycle (21 days).
Some findings of this study:
1. “When OC were initiated at a diameter of 10 ± 1 mm, no ovulations were observed.”
2. “When OC were initiated at a diameter of 14 ± 1 mm 5/14 women (36%) ovulated.”
3. “When OC were initiated at a diameter of 18 ± 1 mm 5/14 women (93%) ovulated.”
The conclusion of the study:
The results of the present study supported the notion that women using the “Sunday Start” method of initiating OC use may be at increased risk of developing follicles capable of ovulating. Dominant follicles (i.e., ≥10 mm) were detected within the first 7 days of the menstrual cycle. Therefore, women who initiate OC use after 7 days of unsuppressed follicle growth may have already selected a dominant follicle that may continue to develop and ovulate. Our findings were also consistent with previous results in which reinitiation of OC use after a 7-day hormone-free interval did not inhibit the development of dominant follicles, but rather allowed their continued development to preovulatory and cystic diameters (10 ).
In summary, follicular development, ovulation, endocrine concentrations, and endometrial development were not suppressed effectively when OC were initiated at late stages of dominant follicle development.
The goal of this study was not to investigate the claims that the pill could act as an abortifacient, and in fact the study indicated that “Endometrial growth was suppressed in the 10-mm group, when all dominant follicles underwent atresia [basically means ovulation did not occur]. However, the endometrial thickness increase to normal follicular phase levels when OC were initiated in the presence of a 14- or 18-mm dominant follicle.”
This indicates that the Endometrial thickness was normal in the case of ovulation while on the pill, seeming to indicate that the endometrium was favourable for implantation of a fertilized. However, this study only looked at the effects of the pill on ovulation and not what on what its effects would have been on what happens after the egg is fertilized. Given the claim that birth control pills are 99% effective7 suggests that these fertilized eggs are not resulting in pregnancy but are being spontaneously aborted.
References:
1., 2., and 3. Product Monogrpah PrYASMIN® 21, PrYASMIN® 28, Drospirenone and Ethinyl Estradiol Tablets, Bayer Standard, 3.0 mg drospirenone and 0.030 mg ethinyl estradiol, Oral Contraceptive, Acne Therapy, p.28. PDF available on the Health Canada site here. [Update:Direct link to Bayer Product Monograph can be found here.]
4. United States Court of Appeals for the Federal Circuit, Bayer Healthcare Pharmaceuticals, Inc. and Bayer Schering Pharma AG v. Watson Pharmaceuticals, Inc. and Watson Laboratories, Inc. and Sandoz Inc. p. 4
5. Ibid. p. 5
6. Fertility and Sterility, Effects of oral contraceptives administered at defined stages of ovarian follicular development, A. R. Baerwald et al, Vol 86, Issue 1, p. 27-35, July 1, 2009.
7. Mayo Clinic.