Maternal risk factors of insufficient fetal growth, iatrogenic prematurity and low birthweight
AbstractThe aim of the study: to assess the risks of delivery of a small fetus in women with IGR and MHV.
Material and methods. A prospective cohort study performed. The main clinical base: the perinatal center of the State Budgetary Institution of Health of the Republic of Crimea “Republican Clinical Hospital named after N.A. Semashko”. Study period: 2018–2020. 23 625 birth histories with 24 086 newborns analyzed. Using the method of generating tables of random numbers generated by the Excel 2007 program, 611 birth histories of women with singleton pregnancy with insufficient fetal growth were selected. Two clinical groups formed: women with IUGR (n=435) and women with SGA (n=176).
Results. In the structure of insufficient fetal growth, IUGR is more than two times higher than the frequency of SGA. The proportion of specified maternal gestational risk factors for underweight fetus is 55.5%, the main of which are preeclampsia (PE), diabetes mellitus (DM), gestational arterial hypertension (GAH) and chronic arterial hypertension (CAH). The relationship of maternal risk factors with IUGR and SGA is not identical. Insufficient fetal growth is excessively associated with the need for delivery by CS (76.31%), iatrogenic prematurity (44.60%). Low birthweight is closely related to preterm birth (p<0.001), not excluding full-term birth in 48.43% of women. Insufficient fetal growth is not necessarily a predictor of low birthweight. The proportion of newborns with low birthweight in a cohort does not reach 50%.
Iatrogenic prematurity with low birthweight is due to gestation-induced hypertensive conditions – most of all with PE (84.38%) and GAG (15.62%). An unknown cause of insufficient fetal growth was shown to be the only predictor of natural delivery (p<0.001), in 29.41% – in preterm pregnancy not earlier than 34 weeks. PE in women with insufficient fetal growth is highly threatened by delivery with very and extremely low birthweight of the newborn, GAG –with lowbirth weight. Diabetes does not rule out IUGR or SGA, but due to diabetic fetopathy, a low birthweight of the newborn is leveled out. Low birthweight is more associated with IUGR than with SGA (OR=6.38). IUGR compared with SGA showed an exclusive relationship with prematurity (p<0.001), but not with the threat of miscarriage in the I (OR=0.48) and II (OR=0.55) trimesters of pregnancy. For the first time, a close relationship was noted between maternal dorsopathy (pain in the lower back and pelvic girdle) and gestation-induced hypertensive conditions (OR=2.67). Dorsopathy with insufficient fetal growth has a predictive significance for IUGR, and not for SGA (OR=3.24), prematurity (OR=4.26). The association of dorsopathy with maternal gestational complications (prematurity, maternal risk factors for insufficient fetal growth, hypertensive conditions in pregnancy, gestational age at delivery, delivery by CS, and low birthweight) is similar to IUGR but not SGA. The frequency of dorsopathy in GAH (45.28%) and PE (43.51%), close to 50%, with an overall frequency in the cohort of 28.97%, requires the search for associative links in the pathogenesis of insufficient fetal growth, hypertensive disorders during pregnancy in women with dorsopathy. This search is also relevant because in 45.5% of women with low fetal weight, risk factors do not fit into routine ideas, are not clearly identified, nullifying efforts to prevent low birth weight.
Conclusion. Insufficient fetal growth is represented mainly by IUGR. IUGR or SGA are not obligate predictors of low birthweight. Maternal gestational risk factors for insufficient fetal growth are predominantly “blank spots”, understood only in 55.5%. The relationship of maternal risk factors with IUGR and SGA is fundamentally different. Being a marker of serious gestational complications, insufficient fetal growth does not prevent delivery by CS, but, on the contrary, is associated with its excessively high frequency. An additional factor aggravating the outcome is the association with iatrogenic prematurity. The main threat of mutually aggravating factors “insufficient fetal growth + iatrogenic prematurity + low birth weight” are hypertensive conditions of pregnant women. In this regard, an important factor interfering with the outcome of pregnancy and undeservedly underestimated is shown dorsopathy, which is closely associated with gestational hypertensive conditions. The perniciousness of a long-term pain syndrome due to dorsopathy with insufficient fetal growth is more likely to be realized in the IUGR, but not in the SGA, and in prematurity. The association of dorsopathy with gestational complications (prematurity, maternal risk factors for poor fetal growth, hypertensive conditions in pregnancy, gestational age at delivery, delivery by CS, and low birth weight), similar to IGR, but not MGA, is not completely clear. In this regard, the prevention of insufficient fetal growth seems to be extremely complex and scrupulous analysis of not only direct, but also indirect risk factors.
Keywords:pregnancy; fetal growth restriction; small for gestational age; low birthweight; dosopathy; hypertensive disorders of pregnancy
Funding. The study had no sponsor support.
Conflict of interest. The authors declare no conflict of interest.
For citation: Ziyadinov A.A., Radzinskaya E.V., Mateikovich E.A., Novikova V.A. Maternal risk factors of insufficient fetal growth, iatrogenic prematurity and low birthweight. Akusherstvo i ginekologiya: novosti, mneniya, obuchenie [Obstetrics and Gynecology: News, Opinions, Training]. 2022; 10 (3): 6–15. DOI: https://doi.org/10.33029/2303-9698-2022-10-3-6-15 (in Russian)