Zhen Han

Preterm birth and low birth weight among in vitro fertilization singletons: A systematic review and meta-analyses

Our objective was to determine the risks of preterm birth (PTB) and low birth weight (LBW) in singletons conceived through in vitro fertilization (IVF)+/-intracytoplasmic sperm injection (ICSI) compared to spontaneously conceived singletons after matching or controlling for at least maternal age. The MOOSE guidelines for meta-analysis of observational studies were followed. Medline and Embase were searched using comprehensive search strategies. Bibliographies of identified articles were reviewed. English language studies examining LBW or PTB in singletons conceived by IVF or IVF/intracytoplasmic sperm injection, compared with spontaneously conceived singletons, that matched or controlled for at least maternal age. Two reviewers independently assessed titles, abstracts, full articles and study quality and extracted data. Dichotomous data were meta-analyzed using relative risks (RR) as measures of effect size with a random effects model and for continuous data weighted mean difference was calculated. Seventeen studies were included with 31,032 singletons conceived through IVF (+/-ICSI) and 81,119 spontaneously conceived singletons. After matching or controlling for maternal age and often other factors, compared to spontaneously conceived singletons, IVF singletons had increased risks of our two primary outcomes, PTB (RR 1.84, 95% CI 1.54, 2.21) and LBW (<2500 g, RR 1.60, 95% CI 1.29, 1.98). Singletons conceived through IVF or IVF/ICSI were at increased risk for late PTB (32-36 weeks, RR 1.52, 95% CI 1.01, 2.30), moderate PTB <32-33 weeks (RR 2.27, 95% CI 1.73, 2.97), very LBW (<1500 g, RR 2.65, 95% CI 1.83, 3.84), and intrauterine growth restriction (RR 1.45, 95% CI 1.04, 2.00), lower birth weights (-97 g, 95% CI -161 g, -33 g) and shorter mean gestations (-0.6 weeks, 95% CI -0.9 weeks, -0.4 weeks). In conclusion, IVF singletons have significantly increased risks of PTB, LBW and other adverse perinatal outcomes compared to spontaneously conceived singletons after matching or controlling for maternal age at least.

Kidney Disease After Preeclampsia: A Systematic Review and Meta-analysis

BACKGROUND Preeclampsia (the development of proteinuria and hypertension after 20 weeks of gestation) is common; however, there is uncertainty about the natural history of subsequent kidney disease. Our objective is to undertake a systematic review and meta-analysis to determine whether women with a history of preeclampsia are at increased risk of subsequent kidney disease. STUDY DESIGN Systematic review and meta-analyses of observational studies. SETTING & POPULATION Studies examining kidney outcomes in women with a history of preeclampsia compared with women with unaffected pregnancies. SELECTION CRITERIA From MEDLINE and EMBASE searches, we included case-control and cohort studies of kidney outcomes at least 6 weeks postpartum in women with and without a history of preeclampsia. 2 independent reviewers determined study eligibility, extracted data, and assessed quality. STUDY FACTOR: Preeclampsia. OUTCOMES Microalbuminuria, proteinuria, serum creatinine level, and estimated glomerular filtration rate. RESULTS 7 cohort studies were included, involving 273 patients with preeclampsia and 333 patients with uncomplicated pregnancies. At a weighted mean of 7.1 years postpartum, 31% of women with a history of preeclampsia had microalbuminuria compared with 7% of women with uncomplicated pregnancies, a 4-fold increased risk, whereas women with severe preeclampsia had an 8-fold increase. Serum creatinine level and estimated glomerular filtration rate were not significantly different at follow-up in women with and without preeclampsia, making it unlikely that they would have been different at baseline. LIMITATIONS Limitations of this systematic review include potential confounders that were not explored in most or any of the original studies, the small size of many studies, and possible publication bias (lack of negative studies). CONCLUSION Women with a history of preeclampsia have an increased risk of microalbuminuria with a prevalence similar to the published prevalence in patients with type 1 diabetes mellitus. Further research is needed to determine whether the increased risk of microalbuminuria persists after adjustment for a thorough set of confounding factors in larger populations and the mechanisms underlying this association.

Low gestational weight gain and the risk of preterm birth and low birthweight: a systematic review and meta‐analyses

Background. Low gestational weight gain is common, with potential adverse perinatal outcomes. Objective. To determine the relation between low gestational weight gain and preterm birth and low birthweight in singletons in developing and developed countries. Data sources. Medline, EMBASE and reference lists were searched, identifying 6 283 titles and abstracts. Methods of study selection. Following the MOOSE consensus statement, two assessors independently reviewed titles, abstracts, full articles, extracted data and assessed quality. Results. Fifty‐five studies, 37 cohort and 18 case‐control, were included, involving 3 467 638 women. In the cohort studies (crude data, generally supported where available by adjusted data and case‐control studies), women with low total gestational weight gain had increases in preterm birth <37 weeks [RR 1.64 (95%CI 1.62–1.65)], 32–36 weeks [RR 1.39 (95%CI 1.38–1.40)] and ≤32 weeks [RR 3.80 (95%CI 3.72–3.88)]. Low total gestational weight gain was associated with increased risks of low birthweight <2 500 g [RR 1.85 (95%CI 1.72–2.00)], in developing and developed countries [RR 1.84 (95%CI 1.71–1.99) and RR 3.02 (95%CI 1.37–6.63), respectively], 1 500–2 500 g [RR 2.02 (95%CI 1.88–2.17)] and <1 500 g (RR 2.00 (95%CI 1.67–2.40)]. Women with low weekly gestational weight gain were at increased risk of preterm birth [RR 1.56 (95%CI 1.26–1.94)], 32–36 weeks [RR 2.43 (95%CI 2.37–2.50)] and ≤32 weeks [RR 2.31 (95%CI 2.20–2.42)] but not low birthweight [RR 1.64 (95%CI 0.89–3.02)]. Conclusions. In this systematic review, we determined that singletons born to women with low total gestational weight gain have higher risks of preterm birth and low birthweight, with the lower the gain, the higher the risks.

Maternal Height and the Risk of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analyses

OBJECTIVE Preterm birth (PTB) and low birth weight (LBW) are the leading causes of neonatal morbidity and mortality, but the effect of maternal height on these outcomes continues to be debated. Our objective was to determine the relationships between maternal height and PTB and LBW. DATA SOURCES Medline and EMBASE were searched from their inceptions. STUDY SELECTION Studies with a reference group that assessed the effect of maternal height on PTB (< 37 weeks) and LBW (< 2500 grams) in singletons were included. DATA EXTRACTION Data were extracted independently by two reviewers. DATA SYNTHESIS Fifty-six studies were included involving 333 505 women. In the cohort studies, the unadjusted risk of PTB in short-statured women was increased (relative risk [RR] 1.23; 95% CI 1.11 to 1.37), as was the unadjusted risk of LBW (RR 1.81; 95% CI 1.47 to 2.23), although not all of the studies with adjusted data found the same association. Maternal tall stature was not associated with PTB (unadjusted RR 0.97; 95% CI 0.82 to 1.14), although LBW was decreased (unadjusted RR 0.56; 95% CI 0.46 to 0.69), but not in the adjusted data. CONCLUSION From our complete systematic review and meta-analyses, to our knowledge the first in this area, we conclude that short-statured women have higher unadjusted risks of PTB and LBW and tall women have approximately one half the unadjusted risk of LBW of women of reference height.

High Gestational Weight Gain and the Risk of Preterm Birth and Low Birth Weight: A Systematic Review and Meta-Analysis

OBJECTIVE Many women have high gestational weight gain (GWG), but potential neonatal consequences are not yet well quantified. We sought to determine the relationship between high GWG and preterm birth (PTB) and low birth weight (LBW) in singleton births. DATA SOURCES We searched Medline and Embase and reference lists. STUDY SELECTION Two assessors independently performed all steps. We selected studies assessing high total or weekly GWG on PTB (< 37 weeks) and LBW (< 2500 grams). DATA EXTRACTION AND SYNTHESIS Thirty-eight studies, 24 cohort and 14 case-control, were included involving 2 124 907 women. Most contained unadjusted data. Women with high total GWG had a decreased risk overall of PTB < 37 weeks (relative risk [RR] 0.75; 95% CI 0.60 to 0.96), PTB 32 to 36 weeks (RR 0.70; 95% CI 0.70 to 0.71), and < 32 weeks (RR 0.87; 95% CI 0.85 to 0.90). High GWG was associated with lower risk of LBW (RR 0.64; 95% CI 0.53 to 0.78). Women with the highest GWG had lower risks of LBW (RR 0.55; 95% CI 0.32 to 0.94) than women with moderately high GWG (RR 0.73; 95% CI 0.60 to 0.89). Women with the highest weekly GWG had greater risks of PTB (RR 1.51; 95% CI 1.47 to 1.55) than women with moderately high weekly GWG (RR 1.09; 95% CI 1.05 to 1.13). Women with high weekly GWG were at increased risk of PTB 32 to 36 weeks (RR 1.14; 95% CI 1.10 to 1.17 and < 32 weeks (RR 1.81; 95% CI 1.73 to 1.90). CONCLUSION Although women with high total GWG have lower unadjusted risks of PTB and LBW, high weekly GWG is associated with increased PTB, and more adjusted studies are needed, as are more studies in obese women. Potential benefits of high GWG for the infant must be balanced against maternal risks and other known infant risks such as high birth weight.

Preterm birth prevention in twin pregnancies with progesterone, pessary, or cerclage: a systematic review and meta-analysis

About half of twin pregnancies deliver preterm, and it is unclear whether any intervention reduces this risk.

Effectiveness of progesterone, cerclage and pessary for preventing preterm birth in singleton pregnancies: a systematic review and network meta‐analysis

Preterm birth (PTB) is the leading cause of infant death, but it is unclear which intervention is best to prevent it.

W15.5 Renal disease after preeclampsia: a systematic review and meta-analyses

cardiovascular disease after preeclampsia, as could be explained by worse cardiovascular health. Results: Ten studies were found, ranging from 6 months to 19 years postpartum. Based on differences in cardiovascular parameters, the calculated odds-ratio for (non)fatal stroke was 1.19 (90%-CI 1.08-1.30) and for (non)fatal ischemic heart disease was 1.14 (90%-CI 0.98-1.31). Discussion: Only a small part of the observed increased risk for cardiovascular disease in former preeclamptic women can be explained by worse cardiovascular health. Although the remaining part might partially be explained by a higher prevalence of trombophilic disorders after preeclampsia, we hypothesize that preeclampsia itself also attributes to an increased cardiovascular risk, making preeclampsia a true independent risk factor for cardiovascular disease.