# Presentation: 551113

## Is there a tradeoff??

- Hormonal contraception
- Breastfeeding

## Potential harms of hormonal contraception

- Quality of milk
- Passage of hormones to the infant
- Infant growth, milk quantity, duration of breastfeeding

## Potential harms of hormonal contraception

_***Quality of milk***_
- Passage of hormones to the infant
- Infant growth, milk quantity

## Quality of milk

- WHO, 1988
- “10 cc aliquots expressed, freeze-dried and transported to London by air”
- Some differences in micro-nutrients and fat content
- Conflicting interpretation of significance
- Infant growth a better, but elusive outcome

## Potential harms of hormonal contraception

- Quality of milk
_***Passage of hormones to the infant***_
- Infant growth, milk quantity, duration of breastfeeding

## Passage of hormones to infant

- Case reports
- Measuring steroid content of breast milk
- Estradiol in breast milk AND in maternal serum after ingestion of pill (50mic)
- 600 cc breastmilk/day from mother taking a 50 mic COC:
- 10 ng of estradiol compared with
- 3-6 ng during anovulatory cycles
- 6-12 ng during ovulatory cycles

**Notes:**
Progestin doses may be even lower with a plasma to milk ratio of 100:15
Compared to EE = 100:25.

## Long term effects:  Nilsson, 1986

- 48 children exposed to COCs in breastmilk
- 48 controls
- 8 year follow-up
- No differences in
- Growth
- Disease
- Intellectual development
- Psychological behavior

**Notes:**
Mean length of breastfeeding was 3.7 months vs 4.6 months in cases vs controls

## Potential harms of hormonal contraception

- Quality of milk
- Passage of hormones to the infant
_***Infant growth, milk quantity, duration of breastfeeding***_

## Combined pills:  3 RCTs 

- 2:  COC vs. placebo
- 1:  COC vs. progestin-only

**Notes:**
To look at potential harms, studies have concentrated on:
Composition of milk and milk volume
Infant growth

Only 3 true RCTs related to combined pills, the last of which was published in 1984

## Problems with RCTs

- Methods of randomization unclear
- Methods for allocation concealment unclear
- Small sample sizes
- Large loss-to-follow-up rates
- Methods for measuring milk output may not reflect breastmilk production

## Semm, 1966

- N = 100 women
- Munich, Germany
- 50 – high dose COC on PP days #1-10
- 50 – identically packaged placebos
- Outcomes
- No differences in milk volume, lactation initiation or infant growth during the first 10 postpartum days

**Notes:**
Lynestrenol 2.5 mg and mestranol .075 mg

Problems:  Limited details about trial, indicates blinding but not how it was done, no allocation concealment mentioned.  No sample size calc, no numerical results or graphs.  No mention of discontinuation, loss to follow-up or exclusions.  Graphs not labeled.  Outcomes were not quantified.

## Miller, 1970

- N= 50 women – Iowa
- 25 – high dose COC  begun at 2 wks x 21 days
- 25 – identically packaged placebos
- Outcomes
- Less milk volume as measured by supplemental feeds and duration of breastfeeding
- Prior successful breastfeeding the best determinant of breastfeeding to 3 mos

**Notes:**
1 mg norethindrone, mestranol 80 mg (like 50 mic EE)

Infants weighed from 1 wks to 5 wks before and after one AM feeding.  Formula and cereal “allowed for supplementation”
Other problems:  In group 1, 88% primips with no previous successful nursing as opposed to placebo where 30% had nursed before

Problems:  Limited details about trial, indicates blinding but not how it was done, no allocation concealment mentioned.  No sample size calc, no numerical results or graphs.  Outcomes not quantified

## WHO, 1984, 1986, 1988

- Hungary, Thailand
- N = 171 women choosing oral contraceptives
- Age 25-35
- Multips (2-4 live births)
- Prior successful breastfeeding
- Infants 2700 – 3700 gms
- 86 – low-dose COC begun 6 wks PP
- 85 – progestin-only begun 6 wks PP

**Notes:**
30% loss to follow-up
Norethindrone 35 mic 

Problems:  Limited details about trial, indicates blinding but not how it was done, no allocation concealment mentioned.  No sample size calc, no numerical results or graphs.  No mention of discontinuation, loss to follow-up or exclusions.  Graphs not labeled

## WHO outcomes

- Breast milk volume @ 4 wk intervals x 6 mos
- Breast milk composition
- Infant growth
- 6, 9, 12, 16, 20 and 24 weeks

**Notes:**
Milk volume:  Women admitted in AM and breastfed the baby.  No Bfing x 2 hours, then baby fed from left breast while breast pump used to empty the right breast x 20 min.  The expressed milk was measured and an aliquot taken for analysis of composition.  No feeding x another 2 hours.  Procedure reversed...  Milk volume at 6 wk PP visit was baseline. 

## WHO results

- Milk volume decreased in both groups from wk 6-24
-  41% COC
- 12% progestin-only
- No differences in
- Supplementation
- “inadequate milk production”
- breastfeeding continuation
- infant growth
- milk composition

## WHO disclaimer

-     “... our method of measuring milk output... may have little relationship to the amount actually ingested by the baby during that or any other 24-hour period.”

**Notes:**
Conclusion was that COCs containing 30 mic EE may diminish milk volume without an effect on infant growth.
Other observations were that
Infants may make up for decreased milk output by increasing the frequency and duration of feeds and the intensity of suckling
Capacity of most women to produce milk exceeds the needs of most infants, 

## WHO conclusions

-    “Combined oral contraceptives cannot be recommended for use during early lactation.  The age at which it seems safe to recommend them will be a subject for debate and controversy.”