MedWire News: Clinicians should advise women on appropriate postpartum contraception during their last trimester of pregnancy in order to avoid unintended conception during lactation, say researchers.

Lactation itself has a contraceptive effect, but for women who do not breastfeed exclusively, the return of ovulation is unpredictable; therefore, which contraception to use and when are crucial, the author notes.

In choosing a method of contraception, it is important that it does not interfere with lactation or have a negative effect on the infant. Non-hormonal methods, such as barrier methods or the copper intrauterine device, are the best option for lactating mothers, study findings suggest.

A World Health Organization (WHO) trial reported a significant decrease in milk volume in women who took combined oral contraceptives compared with progestin-only contraception.

As a result of these findings, the WHO recommends that if combined hormonal methods are the only option, they should be initiated at least 6 months postpartum, only after breastfeeding techniques are well established.

The author stresses, however, that it may be appropriate to initiate progestin-only contraceptives in highly fertile women.

“Both the method of contraception and the timing of the initiation of contraceptives are important decisions that a clinician must help the breastfeeding woman make,” concludes Joyce King (University School of Nursing, Atlanta, Georgia).

Journal abstract