Kask Kristiina, Bäckström Torbjörn, Gulinello Maria, Sundström-Poromaa Inger
Department of Women's and Children's Health, Uppsala University, SE-751 85 Uppsala, Sweden.
Psychoneuroendocrinology. 2008 Jan;33(1):100-7. doi: 10.1016/j.psyneuen.2007.10.005. Epub 2007 Nov 26.
During the postpartum period, estradiol and progesterone levels decline from very high levels during late pregnancy to low levels within 48h of parturition. This period is associated with dysphoric states such as the postpartum blues. Animal studies have suggested an enhanced acoustic startle response and deficient prepulse inhibition (PPI) of startle response following progesterone withdrawal and during the postpartum period. The aim of the current study was to compare acoustic startle response and PPI in healthy third trimester pregnant women and healthy postpartum women.
Twenty-eight healthy pregnant and 21 healthy postpartum women (examined between 48h and 1 week after delivery) were recruited for the study. In addition, to evaluate the time-course of postpartum changes 11 early postpartum women (examined within 48h following delivery) were included in the study. The eyeblink component of the acoustic startle reflex was assessed using electromyographic measurements of m. Orbicularis Oculi. Twenty pulse-alone trials (115dB 40ms broad-band white noise) and 40 prepulse-pulse trials were presented. The prepulse stimuli consisted of a 115dB 40ms noise burst preceded at a 100ms interval by 20ms prepulses that were 72, 74, 78 or 86dB.
Pregnant women exhibited lower levels of PPI compared to late postpartum women, p<0.05. There was no difference between pregnant women and postpartum women examined within 48h of delivery. There was no difference in startle response or habituation to startle response between pregnant women and either of the two groups of postpartum women.
Healthy women display lower levels of PPI during late pregnancy when estradiol and progesterone levels are high compared to the late postpartum period when ovarian steroid levels have declined.
在产后期间，雌二醇和孕酮水平从妊娠晚期的极高水平下降至分娩后48小时内的低水平。这一时期与诸如产后情绪低落等烦躁状态相关。动物研究表明，孕酮撤退后及产后期间惊跳反应增强且前脉冲抑制（PPI）惊跳反应不足。本研究的目的是比较健康的孕晚期孕妇和健康的产后女性的听觉惊跳反应和PPI。
招募28名健康孕妇和21名健康产后女性（在分娩后48小时至1周之间接受检查）参与本研究。此外，为评估产后变化的时间进程，11名产后早期女性（在分娩后48小时内接受检查）也纳入研究。使用眼轮匝肌的肌电图测量来评估听觉惊跳反射的眨眼成分。呈现20次单脉冲试验（115分贝40毫秒宽带白噪声）和40次前脉冲 - 脉冲试验。前脉冲刺激由一个115分贝40毫秒的噪声爆发组成，在100毫秒间隔前有20毫秒的前脉冲，其强度为72、74、78或86分贝。
与产后晚期女性相比，孕妇的PPI水平较低，p<0.05。在分娩后48小时内接受检查的孕妇和产后女性之间没有差异。孕妇与两组产后女性中的任何一组在惊跳反应或对惊跳反应的习惯化方面均无差异。
与卵巢类固醇水平已下降的产后晚期相比，健康女性在妊娠晚期雌二醇和孕酮水平较高时PPI水平较低。
