Risk of ovulation during lactation.

Area of Science:

• Reproductive Endocrinology
• Maternal-Child Health
• Lactational Amenorrhea

Background:

• The return of ovulation and menstruation postpartum is influenced by breastfeeding patterns.
• Lactational amenorrhea is a natural method of birth spacing, but its effectiveness varies.

Purpose of the Study:

• To investigate the relationship between breastfeeding frequency, duration, and infant feeding patterns on postpartum ovarian activity.
• To determine the timing of ovulation and the incidence of luteal phase defects in breastfeeding mothers.

Main Methods:

• Prospective study involving 60 mothers in Baltimore and 41 in Manila.
• Daily recording of infant feeding patterns and weekly interviews.
• Monitoring ovarian activity via hormone metabolite assays in daily urine samples.

Main Results:

• Mean time to first ovulation was 27 weeks in Baltimore and 38 weeks in Manila.
• 41% of first ovulations exhibited luteal phase defects; 45.1% had anovular menses in the first 6 months postpartum.
• Higher breastfeeding frequency and duration, with less supplementation, reduced ovulation risk.

Conclusions:

• Exclusive breastfeeding, regardless of feed frequency or duration, significantly reduces ovulation risk within the first six months postpartum.
• Resumption of menstruation before six months or continued breastfeeding beyond six months increases ovulation risk, indicating a need for contraception.
• Breastfeeding practices play a crucial role in postpartum fertility regulation, but individual variations and specific conditions necessitate careful monitoring and potential contraceptive use.