Effect of Parity on Pregnancy Outcome in Women with Type-1 Diabetes ? A Swedish Population-based Study

Martina Persson Dharmintra Pasupathy

doi:10.4172/2155-6156.1000534

Abstract

Aim: Women without diabetes are at increased risk of pregnancy complications in their first pregnancy. The aim of this study was to investigate if the risk of adverse pregnancy outcomes also differs with parity in women with type 1 diabetes (T1DM). Methods: Population based prospective cohort study of all singleton pregnancies to women with T1DM (n=4092) in Sweden between 1998 and 2007. Data was derived from the Swedish Medical Birth Registry. Outcomes of interest were preeclampsia (PE), gestational hypertension (GH), major malformation, perinatal mortality (PMR), preterm delivery, large for gestational age (LGA), small for gestational age (SGA) and neonatal death. Logistic regression analysis was used to obtain odds ratios (OR) for adverse outcomes in relation to parity. Interaction tests were performed to compare the association of interest in non-diabetic pregnancies. Results: The risk of GH (adjusted OR 0.63 95% CI [0.37-1.05]), major malformation (1.25 [0.88-1.77]), preterm delivery (0.83 [0.70-1.00]) and neonatal death (5.34 [0.57-49.8]) did not differ significantly with parity in women with T1DM. Multiparous women with T1DM had lower risk of PE (0.35 [0.28-0.43]), SGA (0.44 [0.29-0.68]), PMR (0.22 [0.10-0.51]) and significantly increased odds of LGA (1.96 (1.71-2.25). In women without diabetes (n = 905 565) the risk of all outcomes except LGA and neonatal death were significantly lower in multiparous women (p value for interaction < 0.05). Conclusion: Multiparity in women with and without T1DM is associated with reduced risks for most adverse outcomes except LGA. Within the T1DM cohort, the risk for major malformations was slightly increased in offspring of multiparous women.

Highlights

It is well recognized that pregnancy in type 1 diabetes is associated with increased risks of adverse pregnancy outcomes, including preeclampsia, major malformations, perinatal mortality, birth trauma, preterm delivery and neonatal morbidities [1,2,3,4]
It has been proposed that a contributing factor to the increased risk in primiparous women could be a higher prevalence of maternal risk factors in this group, including lower maternal age, lower pre-pregnancy body mass index (BMI), insufficient pregnancy weight gain, hypertensive disorders of pregnancy, poor education, noncohabiting, smoking and socioeconomic stress [13,14,15]
The parity distribution was almost identical in women with and without T1DM with approximately 45% of women with one birth, 36% with two births, 14% with three births and 5% with four or more births

Summary

Introduction

It is well recognized that pregnancy in type 1 diabetes is associated with increased risks of adverse pregnancy outcomes, including preeclampsia, major malformations, perinatal mortality, birth trauma, preterm delivery and neonatal morbidities [1,2,3,4]. In women without type 1 diabetes, obstetric complications are more common in the first pregnancies (primiparous) compared with subsequent pregnancies and births (multiparas) These complications include preeclampsia, gestational hypertension, stillbirth, perinatal mortality, fetal growth restriction, preterm birth, instrumental delivery and delivery by cesarean section [5,6,7,8,9,10,11,12]. The higher risk for complications in primiparas may partly be attributed to the fact that fecundity issues may be more common in these women and that higher-risk women are less likely to have subsequent pregnancies. This selection can only partly explain the observed reduced risk of complications with increasing parity [17]

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