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    Safe contraception for women with medical conditions

     

    Obesity

    Intrauterine devices (IUDs) are Category 1. The mechanism of contraceptive action of copper and hormonal IUDs is independent of systemic hormonal levels, given that both types work locally within the uterus. Therefore, their efficacy is not affected by body weight.7 The CHOICE project, which had a sample of 6000 women, of whom 35% were obese, revealed no difference in efficacy of the levonorgestrel (LNG) IUD and the copper-T IUD when stratified by BMI.8

    Implant is Category 1. A secondary analysis of the CHOICE project participants revealed a baseline BMI of
    30.1 kg/m2. Of these participants, 28% were overweight and 35% were obese. Their analysis showed no statistically significant difference in the efficacy of BMI.8

    The injectable contraceptive depo-medroxyprogesterone acetate (DMPA) is Category 1 for BMI >/=30 kg/m2. In regard to efficacy and weight, DMPA has equal efficacy in normal weight and obese women.9 In a more recent study in obese women using the subcutaneous formulation, no pregnancies were detected among their study population of whom 36% were obese or overweight.10 As pertains to the contraceptive’s effect on weight in obese women, among adult DMPA users, obese women did not gain more weight than nonobese women.11

    Combined hormonal contraception (CHC) is Category 2 in the nonpostpartum period for obesity. The 2 main issues with CHC use in obese women are efficacy and VTE risk. The evidence is conflicting as to whether obesity affects combined contraceptive pill efficacy. Obesity itself is a risk factor for noncompliance with combined oral contraceptive pills.12 The studies that do exist do not differentiate between contraceptive method failure due to non-adherence and pharmacokinetics. A recent meta-analysis from Phase 3 clinical trials of combination oral contraceptives (COCs) revealed a hazard ratio of 1.44 (95% confidence interval: 1.06–1.95; P=.018), suggesting that there is a higher pregnancy rate during COCs use for obese women compared to non-obese women after adjusting for age and race.13 The commercially available contraceptive patch failure rate in women with the highest weight had a similar rate of failure compared to the overall rate (1.0% vs 0.83% in overall group) but the failures clustered in the highest weight category defined as ≥ 90 kg.14 As to the potential increase in risk of VTE, although the absolute risk of VTE remains low among obese users of the combined contraceptive pill, obesity more than doubles the risk of VTE when compared with normal weight women not using hormonal contraception (60 per 100,000 for class 1 obesity (BMI 30–34.9) versus 12–20 per 100,000 in normal weight women.15 This is still a lower risk of VTE among women who are obese and pregnant, which is estimated at 100–200 per 100,000.

    Breastfeeding

    Regarding IUDs, the immediate postplacental placement (<10 minutes of delivery of the placenta) of the copper-T IUD is Category 1 and LNG-IUD is Category 2.

    Both types of IUDs are classified as Category 1 for placement >4 weeks postpartum for all women despite breastfeeding status. Evidence regarding LNG-IUD and breastfeeding has been limited with some mixed results. One randomized, controlled trial reported decreased exclusive breastfeeding in postplacental LNG-IUD compared with delayed postpartum insertion, while another trial reported similar breastfeeding rates between post-placental and delayed insertion.16,17 Neither study was designed to evaluate breastfeeding continuation. When placed 6 to 8 weeks after delivery, the copper-T IUD compared with the LNG-IUD had no effect on breastfeeding continuation or infant growth parameters.18 ACOG endorses the use of immediate postpartum IUDs.19

     

    Neena T Qasba, MD
    Dr Qasba is Family Planning Fellow, Department of Obstetrics, Gynecology, and Reproductive Sciences at Yale School of Medicine, New ...
    Nancy L. Stanwood, MD, MPH
    Dr. Stanwood is Section Chief, Family Planning, and Director, Fellowship in Family Planning, Department of Obstetrics, Gynecology & ...

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    • UBM User
      As an accredited Fertility Educator with Natural Fertility NZ and their Clinical Supervisor it is a real disappointment to see that LAM (lactational amenorrhoea method) was not mentioned or investigated as a valid option for client 1. It has no side effects to the mother or baby and actually promotes breastfeeding.

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