Merklinger-Gruchala Anna, Jasienska Grazyna, Kapiszewska Maria
Department of Health and Medical Sciences, Andrzej Frycz Modrzewski Krakow University, ul. Gustawa Herlinga-Grudzińskiego 1, 30-705, Krakow, Poland.
Department of Environmental Health, Faculty of Health Sciences, Jagiellonian University Medical College, ul. Grzegorzecka 20, 31-531, Krakow, Poland.
Am J Hum Biol. 2015 Sep-Oct;27(5):660-6. doi: 10.1002/ajhb.22708. Epub 2015 Mar 7.
Short interpregnancy intervals (IPI) and high parity may be synergistically associated with the risk of unfavorable pregnancy outcomes. This study tests if the effect of short IPI on the odds ratio for low birth weight (LBW, <2,500 g) differs across parity status.
The study was carried out on the birth registry sample of almost 40,000 singleton, live-born infants who were delivered between the years 1995 and 2009 to multiparous mothers whose residence at the time of infant's birth was the city of Krakow. Multiple logistic regression analyses were used for testing the effect of IPI on the odds ratio (OR) for LBW, after controlling for employment, educational and marital status, parity, sex of the child, maternal and gestational age. Stratified analyses (according to parity) and tests for interaction were performed.
Very short IPI (0-5 months) was associated with an increased OR for LBW, but only among high parity mothers with three or more births (OR = 2.64; 95% CI 1.45-4.80). The test for interaction between very short IPI and parity on the OR for LBW was statistically significant after adjustment for multiple comparisons (P = 0.04). Among low parity mothers (two births) no statistically significant associations were found between IPI and LBW after standardization.
Parity may modify the association between short birth spacing and LBW. Women with very short IPI and high parity may have a higher risk of having LBW infants than those with very short IPI but low parity.
妊娠间隔期短（IPI）和高生育次数可能与不良妊娠结局风险存在协同关联。本研究旨在检验妊娠间隔期短对低出生体重（LBW，<2500克）比值比的影响在不同生育次数状态下是否存在差异。
本研究基于1995年至2009年间在克拉科夫市出生的近40000名单胎活产婴儿的出生登记样本进行，这些婴儿的母亲为经产妇。在控制就业、教育和婚姻状况、生育次数、孩子性别、母亲年龄和孕周后，采用多元逻辑回归分析来检验IPI对LBW比值比（OR）的影响。进行了分层分析（根据生育次数）和交互作用检验。
极短的IPI（0 - 5个月）与LBW的OR升高相关，但仅在生育三次或更多次的高生育次数母亲中如此（OR = 2.64；95%CI 1.45 - 4.80）。在对多重比较进行校正后，极短IPI与生育次数对LBW的OR的交互作用检验具有统计学意义（P = 0.04）。在低生育次数母亲（生育两次）中，标准化后未发现IPI与LBW之间存在统计学显著关联。
生育次数可能会改变短生育间隔与LBW之间的关联。妊娠间隔期极短且生育次数高的女性生育低出生体重婴儿的风险可能高于妊娠间隔期极短但生育次数低的女性。
