CECharlotte Ellertson

Charlotte Ellertson

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

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Previous Organizations / Institutes

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Charlotte Ellertson has a total of 26 co-authors. Here are the top co-authors by number of shared publications:

  • Aileen Spears

    Ibis Reproductive Health, Cambridge, Massachusetts; Abacus Centre for Contraception and Reproductive Health, Liverpool, United Kingdom; Planned Parenthood of Greater Iowa, Des Moines, Iowa; Glasgow Centre for Family Planning and Sexual Health, Glasgow, United Kingdom; and Office of Population Research, Princeton University, Princeton, New Jersey

    2 shared publications
  • James Trussell

    Ibis Reproductive Health, Cambridge, Massachusetts; Abacus Centre for Contraception and Reproductive Health, Liverpool, United Kingdom; Planned Parenthood of Greater Iowa, Des Moines, Iowa; Glasgow Centre for Family Planning and Sexual Health, Glasgow, United Kingdom; and Office of Population Research, Princeton University, Princeton, New Jersey

    2 shared publications
  • Karen Johnstone

    Ibis Reproductive Health, Cambridge, Massachusetts; Abacus Centre for Contraception and Reproductive Health, Liverpool, United Kingdom; Planned Parenthood of Greater Iowa, Des Moines, Iowa; Glasgow Centre for Family Planning and Sexual Health, Glasgow, United Kingdom; and Office of Population Research, Princeton University, Princeton, New Jersey

    2 shared publications
  • Sue Ferden

    Ibis Reproductive Health, Cambridge, Massachusetts; Abacus Centre for Contraception and Reproductive Health, Liverpool, United Kingdom; Planned Parenthood of Greater Iowa, Des Moines, Iowa; Glasgow Centre for Family Planning and Sexual Health, Glasgow, United Kingdom; and Office of Population Research, Princeton University, Princeton, New Jersey

    2 shared publications
  • Alison Bigrigg

    Ibis Reproductive Health, Cambridge, Massachusetts; Abacus Centre for Contraception and Reproductive Health, Liverpool, United Kingdom; Population Council, Johannesburg, South Africa; Glasgow Centre for Family Planning and Sexual Health, Glasgow, United Kingdom; Planned Parenthood of Greater Iowa, Des Moines, Iowa; and Office of Population Research, Princeton University, Princeton, New Jersey

    1 shared publication
  • Amy Meehan

    1 shared publication

Latest Publications

  • Knowledge and perceptions of HIV among peripartum women and among men whose wives are of reproductive age, northern Thailand

    by Kanokwan Tharawan, Chomnad Manopaiboon, Charlotte E. Ellertson, Khanchit Limpakarnjanarat, Peter H. Kilmarx, Christiana Coggins, Supaporn Chaikummao, Timothy D. Mastro, Christopher J. Elias


  • Modifying the Yuzpe regimen of emergency contraception: a multicenter randomized controlled trial

    by C Ellertson

    Emergency contraceptives can prevent unintended pregnancy after unprotected intercourse. The best-studied regimen ("Yuzpe") consists of ordinary combined oral contraceptives containing levonorgestrel and ethinyl estradiol. Women traditionally take one dose within 72 hours after unprotected intercourse, and a second dose 12 hours later. Historically, half experience nausea and a fifth vomit. The purpose of this study was to determine whether 1). women could use combined oral contraceptives other than those containing levonorgestrel and 2). eliminating the second dose improves comfort and convenience. Women presenting within 72 hours after unprotected intercourse were randomized to receive 1). standard two-dose Yuzpe, 2). a variant of Yuzpe substituting norethindrone for levonorgestrel, or 3). only the first dose of Yuzpe, followed 12 hours later by a placebo. Perfect-use failure rates were low in all groups and did not differ in a statistically significant way (standard Yuzpe 2.0% [n = 589], norethindrone-ethinyl estradiol 2.7% [n = 547], single dose of Yuzpe 2.9% [n = 546]). Typical-use failure rates were slightly higher but similarly did not differ significantly. Side effects were similar across groups, except that women taking the single dose reported half the vomiting. Taking the pills with food did not seem to reduce nausea or vomiting, and the pills were not more effective when started sooner after unprotected intercourse. Oral contraceptives containing norethindrone-ethinyl estradiol work approximately as well for emergency contraception as levonorgestrel-ethinyl estradiol formulations and should be offered when first-line therapies are not available.


  • Modifying the Yuzpe Regimen of Emergency Contraception

    by Charlotte Mpa Ellertson, Anne Mffp Webb, Kelly Msc Blanchard, Alison Bigrigg, Sue Do Haskell, Tara Shochet, James Trussell

    OBJECTIVE Emergency contraceptives can prevent unintended pregnancy after unprotected intercourse. The best-studied regimen (“Yuzpe”) consists of ordinary combined oral contraceptives containing levonorgestrel and ethinyl estradiol. Women traditionally take one dose within 72 hours after unprotected intercourse, and a second dose 12 hours later. Historically, half experience nausea and a fifth vomit. The purpose of this study was to determine whether 1) women could use combined oral contraceptives other than those containing levonorgestrel and 2) eliminating the second dose improves comfort and convenience. METHODS Women presenting within 72 hours after unprotected intercourse were randomized to receive 1) standard two-dose Yuzpe, 2) a variant of Yuzpe substituting norethindrone for levonorgestrel, or 3) only the first dose of Yuzpe, followed 12 hours later by a placebo. RESULTS Perfect-use failure rates were low in all groups and did not differ in a statistically significant way (standard Yuzpe 2.0% [n = 589], norethindrone–ethinyl estradiol 2.7% [n = 547], single dose of Yuzpe 2.9% [n = 546]). Typical-use failure rates were slightly higher but similarly did not differ significantly. Side effects were similar across groups, except that women taking the single dose reported half the vomiting. Taking the pills with food did not seem to reduce nausea or vomiting, and the pills were not more effective when started sooner after unprotected intercourse. CONCLUSION Oral contraceptives containing norethindrone–ethinyl estradiol work approximately as well for emergency contraception as levonorgestrel–ethinyl estradiol formulations and should be offered when first-line therapies are not available.


  • Extending the time limit for starting the Yuzpe regimen of emergency contraception to 120 hours

    by C Ellertson

    Current protocols state that the Yuzpe regimen of emergency contraception can be initiated up to 72 hours after unprotected intercourse. The purpose of this study was to determine whether the window for emergency hormonal contraception can be extended to 120 hours. In an observational study, we tracked 111 women who requested emergency contraception between 72 and 120 hours after unprotected sex but refused postcoital copper intrauterine devices (IUDs), preferring instead the Yuzpe regimen. We compared failure rates for this group with rates among 675 otherwise similar women who started the same therapy within 72 hours. Both perfect use (1.9%) and typical use (3.6%) failure rates were low among women presenting between 72 and 120 hours after unprotected intercourse. These rates did not statistically differ from failure rates for the standard Yuzpe regimen (2.0% during perfect use and 2.5% during typical use). Our small sample size of 111, however, gave us just 25% power to detect a doubling in the failure rates (2% to 4%) and 59% power to detect a tripling in the failure rates (2% to 6%). The 72-hour cutoff for the Yuzpe regimen of emergency contraception appears needlessly restrictive. Women who request this therapy more than 72 hours after unprotected sex should be allowed to receive it, particularly if they decline postcoital insertion of a copper IUD and would otherwise have no options for reducing pregnancy risk.


  • Extending the Time Limit for Starting the Yuzpe Regimen of Emergency Contraception to 120 Hours

    by Charlotte Mpa Ellertson, Margaret Rgn Evans, Sue Ferden, Clare Rn Leadbetter, Aileen Spears, Karen Johnstone, James Trussell

    OBJECTIVE Current protocols state that the Yuzpe regimen of emergency contraception can be initiated up to 72 hours after unprotected intercourse. The purpose of this study was to determine whether the window for emergency hormonal contraception can be extended to 120 hours. METHODS In an observational study, we tracked 111 women who requested emergency contraception between 72 and 120 hours after unprotected sex but refused postcoital copper intrauterine devices (IUDs), preferring instead the Yuzpe regimen. We compared failure rates for this group with rates among 675 otherwise similar women who started the same therapy within 72 hours. RESULTS Both perfect use (1.9%) and typical use (3.6%) failure rates were low among women presenting between 72 and 120 hours after unprotected intercourse. These rates did not statistically differ from failure rates for the standard Yuzpe regimen (2.0% during perfect use and 2.5% during typical use). Our small sample size of 111, however, gave us just 25% power to detect a doubling in the failure rates (2% to 4%) and 59% power to detect a tripling in the failure rates (2% to 6%). CONCLUSION The 72-hour cutoff for the Yuzpe regimen of emergency contraception appears needlessly restrictive. Women who request this therapy more than 72 hours after unprotected sex should be allowed to receive it, particularly if they decline postcoital insertion of a copper IUD and would otherwise have no options for reducing pregnancy risk.


    • 1 January 2002
      • Vol. 57  (4) , 200-3, 214

    Differences between emergency contraception users in the United States and the United Kingdom.

    by Kelly Blanchard, Sue Haskell, Sue Ferden, Karen Johnstone, Aileen Spears, Margaret Evans, Clare Leadbetter, Sarah Carlson, Amy Meehan, Katrina Abuabara, et al.

    To characterize emergency contraception (EC) users and clinical trial participants in the United States and the United Kingdom, comparing previous EC use and awareness, contraceptive history, and experience with EC. We collected data from all EC seekers (n=5383) at 1 US and 2 UK clinics (9/97-8/98). We also collected detailed information from women (n=2157) enrolling in an EC trial at the first 3 clinics and 2 additional UK sites (9/97-2/00). More US (16%) than UK (4%) women reported additional acts (other than in the last 5 days) of unprotected sex during the cycle in which they sought EC. Fifty-eight percent of UK trial participants had used EC previously compared to 18% in the United States. Most participants in both groups used contraception regularly and reported needing EC because of condom breaks (67% and 56%). More UK than US participants used an ongoing method of contraception (38% v 28%). US women reported more side effects at follow-up than UK women did (76% v 59%), although similar proportions would take EC again or recommend it. US and UK women in our trial experienced different side effects. Researchers should use caution when presenting aggregate results from international multicenter trials. In addition, readers should be aware that such aggregate results might mask important geographical differences. More research on experience with EC and barriers to contraceptive use in the United States is needed.