Thyrotrophin-Releasing Hormone—A Lactation-Promoting Agent?

Abstract

Objective-To study the lactational and hormonal responses to nasal administration of thyrotrophin-releasing hormonc (TRH) in puerperal women with inadequate lactation. Design-Prospective randomized double-blind placebo-controlled study. Subjects-19 pucrperal womcn with inadequate lactation (<50% of normal milk yield) on the 5th day postpartum. Interventions-10 women were allocated to receive TRH administered by a nasal spray of 1 mg, four times daily, between suckling episodes, for 10 consecutive days starting on day 6 postpartum. Nine women werc allocated to receive placebo sprays. Main outcome measures-Daily milk yield, serum lcvcls of prolactin and thyroid hormoncs. Results-Before trcatment all the women had significant prolactin responses to TRH and suckling stimuli. At the end of 10 days of treatment, milk yield incrcascd significantly in the TRH group from a mean of 1424 (SD 33.9) to 2534 (SD 105.3) @day (P = 0414). There was no significant change in the placebo group. Basal prolactin levels increased from a mean of 117.4 pgA (SD 45.2) to 173.3 pg/l (SD 55.5) (P<O.OOl) in the TRH group whereas in thc placebo group prolactin levels decreased from 137.2 (SD 69.5) to 8 2 4 (SD 37.7) pg'l. A further rise in prolactin levels and milk yield was seen in seven women in the TRH group who received a sccond 10-day course of TRH treatment at their own request. There was no significant change in lcvcls of thyroid stimulating hormonc, thyroxine and triiodothyroninc during treatment in either of the two treatment groups and no signs of hyperthyroidism. Corzclusion-Rcpeated nasal TRH administration bctwccn suckling episodes may improvc defective lactation.It is well established that prolactin is essential for the function of the mammary gland. Dopaminc

Pharmacological Overview of Galactogogues

“…In another study, TRH administration for one month, at doses of 5 mg twice a day PO, did not change PRL blood concentration in human [106]. TRH has been effective in the induction of lactation in mothers with agalactia 10–150 days after birth [107], but its galactogogue effect is variable [108]. Its half-life in rats was found to be 4.16 minutes [109].…”

“…No side effects have been found in infants [105]. Some cases of iatrogenic hyperthyroidism and brief episodes of sweating have been reported in mothers [106, 108]. There are no clinical studies about its use in veterinary medicine, and more research is needed.…”

Safety and Efficacy of Galactogogues: Substances that Induce, Maintain and Increase Breast Milk Production

“…Side effects for infant and for mother: No side effect has been found in infants (71) Some cases of iatrogenic hyperthyroidism (70) and short episodes of diaphoresis (74) have been found in mothers. TRH administration increases the maternal levels of T3 and T4, and both hormones appear at low concentration in the mother's milk (37).…”

Recognizing and Treating Delayed or Failed Lactogenesis II

“…Thyroid hormones are essential for efficient milk production and, in animals, appear to be necessary for mammary responsiveness to growth hormone and prolactin during lactation 11 . One study in women with insufficient lactation found that the nasal administration of thyrotrophin‐releasing factor (TRH) increased prolactin and daily milk volume 12 . In this randomized, double‐blinded study, 19 women with insufficient lactation (<50% of normal milk yield) were allocated to receive TRH or a placebo nasal spray.…”

“…11 One study in women with insufficient lactation found that the nasal administration of thyrotrophin-releasing factor (TRH) increased prolactin and daily milk volume. 12 In this randomized, doubleblinded study, 19 women with insufficient lactation (Ͻ50% of normal milk yield) were allocated to receive TRH or a placebo nasal spray. At the end of 10 days of treatment, milk yield increased significantly (P ϭ .014) in the TRH group from a mean of 142 Ϯ 33.9 g/d to 253 Ϯ 105.3 g/d compared to no change in the placebo group.…”