Thyrotrophin‐releasing hormone—a lactation‐promoting agent?

Abstract

Objective— To study the lactational and hormonal responses to nasal administration of thyrotrophin‐releasing hormone (TRH) in puerperal women with inadequate lactation. Design— Prospective randomized double‐blind placebo‐controlled study. Subjects— 19 puerperal women 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 were allocated to receive placebo sprays. Main outcome measures— Daily milk yield, serum levels of prolactin and thyroid hormones. Results— Before treatment all the women had significant prolactin responses to TRH and suckling stimuli. At the end of 10 days of treatment, milk yield increased significantly in the TRH group from a mean of 142–0 (SD 33.9) to 253–0 (SD 105.3) g/day (P = 0.014). There was no significant change in the placebo group. Basal prolactin levels increased from a mean of 117–4 μg/1(SD 45.2) to 173–3 μg/1 (SD 55.5) (P < 0.001) in the TRH group whereas in the placebo group prolactin levels decreased from 137–2 (SD 69.5) to 82–0 (SD 37.7) μg/1. A further rise in prolactin levels and milk yield was seen in seven women in the TRH group who received a second 10‐day course of TRH treatment at their own request. There was no significant change in levels of thyroid stimulating hormone, thyroxine and triiodothyronine during treatment in either of the two treatment groups and no signs of hyperthyroidism. Conclusion— Repeated nasal TRH administration between suckling episodes may improve defective lactation.

A Comparative Review of the Extrinsic and Intrinsic Factors Regulating Lactose Synthesis

“…The ability of thyroid hormones to regulate lactose and milk production has been the subject of inconsistent investigation over several decades. Oral or intranasal thyroid hormone releasing hormone (TRH) administered to breastfeeding individuals for 4 weeks postpartum increased PRL secretion, milk production, and in some cases milk lactose content without a change in milk protein or fat content [61][62][63][64]. The greatest positive impact of TRH on milk production and lactose content was among those with insufficient milk production who received TRH in the first week postpartum [61][62][63][64].…”

Usefulness of recombinant human prolactin for treatment of poor puerperal lactation in a rat model

“…Alternatively, several drugs (e.g. sulphide, TRH, metoclopramide) that stimulate PRL secretion are used to increase endogenous PRL and to augment lactation (13)(14)(15)(16). We use sulpiride for women with poor lactation because it stimulates PRL release from the pituitary by blocking dopamine receptors and increases milk secretion from the mammary glands (13,14).…”

What Evidence Do We Have for Pharmaceutical Galactagogues in the Treatment of Lactation Insufficiency?—A Narrative Review

“…Definitions for lactation insufficiency varied widely across studies and involved the use of an absolute volume measure (e.g., <500 mL/day) [27,28,33,34,38,44,45], relative volume measure (e.g., < 250 mL/kg/day) [29,35,37,39,41,42,46], requirement for supplemental feeds [30,31,32,43], insufficient infant weight gain [39], or certain reduction in supply based on previous milk production [14,23,37]. Given that there is no universally accepted definition of lactation insufficiency in the literature, it is unsurprising that definitions used across studies vary greatly.…”

“…An overview of controlled intervention trials evaluating the efficacy of various galactagogues is provided in Table 1. Domperidone [27,28,29,30,31,32,33,34,35,36,37] and metoclopramide [28,29,38,39,40] appear to be the most commonly studied galactagogues in the setting of established lactation insufficiency, with limited studies evaluating the effects of other galactagogues including sulpiride [41,42], growth hormone [43,44], human recombinant prolactin [45], thyrotropin releasing hormone [46,47], and metformin [48]. No studies have evaluated the use of oxytocin in the treatment of lactation insufficiency.…”

“…The thyrotrophin-releasing hormone (TRH) acts on the anterior pituitary to increase serum prolactin concentrations (Figure 1). Two studies were identified that involved the administration of TRH, producing mixed results [46,47]. One study randomised women to receive either TRH ( n = 5) or placebo ( n = 4) orally [47].…”