Survey of maternal sleep practices in late pregnancy in a multi-ethnic sample in South Auckland, New Zealand

The supine sleep position in late pregnancy is a major risk factor for stillbirth, with a population attributable risk of 5.8% and one in four pregnant women reportedly sleeping in a supine position. Although the mechanisms linking the supine sleep position and late stillbirth remain unclear, there is evidence that it exacerbates pre-existing maternal sleep disordered breathing, which is another known risk factor for adverse perinatal outcomes. Given that maternal sleep position is a potentially modifiable risk factor, the aim of this study was to characterize and correlate uteroplacental and fetal hemodynamics, including cardiac function, in a cohort of women with apparently uncomplicated pregnancies with their nocturnal sleep position. This was a prospective observational cohort study at an Australian tertiary obstetric hospital. Women were asked to complete a series of questions related to their sleep position in late pregnancy after 35 weeks of completed gestation. They also underwent an ultrasound assessment where Doppler indices of various fetoplacental vessels and fetal cardiac function were measured. Regional cerebral perfusion was also assessed. Pregnancy outcome data was extracted from the electronic hospital database for analysis. A total of 274 women were included in the final analysis. Of these, 78.1% (214/274) reported no supine sleep, and 21.9% (60/274) reported going to sleep in a supine position. The middle cerebral artery, anterior cerebral artery, and vertebral artery pulsatility indices were all significantly lower in the supine sleep cohort, as was the cerebroplacental ratio. There were no significant differences in the mode or indication for delivery or in serious neonatal outcomes, including 5-min Apgar score < 7, acidosis, and neonatal intensive care unit admission between cohorts. Women in the supine cohort were more likely to have an infant with a BW > 90th centile (p = 0.04). This data demonstrates fetal brain sparing in association with the maternal supine sleep position in a low-risk population. This data contributes to the growing body of literature attempting to elucidate the etiological pathways responsible for the association of late stillbirth with the maternal supine sleep position.

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Maternal constraint and the birthweight response to mid-pregnancy shearing

Australian Journal of Agricultural Research ◽

10.1071/ar01130 ◽

2002 ◽

Vol 53 (5) ◽

pp. 511 ◽

Cited By ~ 19

Author(s):

P. R. Kenyon ◽

S. T. Morris ◽

D. K. Revell ◽

S. N. McCutcheon

Keyword(s):

New Zealand ◽

Fetal Growth ◽

Low Birthweight ◽

Late Pregnancy ◽

The Other ◽

Adequate Level ◽

In Pregnancy ◽

Maintenance Group

Pregnancy shearing has been shown to increase lamb birthweights. However, results have been variable between studies. It has been suggested that the birthweight response to pregnancy shearing is greatest in conditions in which the unshorn dam gives birth to lambs of low birthweight. This study was designed to examine the birthweight response under 2 differing maternal treatments (one designed to restrict fetal growth and the other designed not to limit fetal growth), with the aim of explaining the variation observed in pregnancy shearing studies. Mixed aged Romney cross ewes were either shorn during mid pregnancy (n = 55) or left unshorn (n = 50). At shearing, ewes were split into either a ‘maintenance’ group (64 kg at shearing and fed to permit total ewe liveweight gain equivalent to expected conceptus growth during mid- to late-pregnancy) (n = 52) or a ‘low’ group (54 kg at shearing and fed to permit total ewe liveweight to increase at half the expected conceptus growth during mid- to late-pregnancy) (n = 53), respectively. Mid-pregnancy shearing was found to increase the birthweights of singletons (5.6 v. 4.9 kg, P < 0.05) but not twins, and of lambs born to maintenance group ewes (by 0.6 kg, P < 0.05), but not low group ewes. Additionally, mid-pregnancy shearing had no effect on the thermoregulatory capacity of twin-born lambs. When the results of this study are considered with those of previous New Zealand pregnancy shearing studies, they suggest that there are 2 criteria (and not one, as previously suggested) that must be met to achieve a response to pregnancy shearing. Firstly, the dam must have the potential to respond [i.e. have been destined to give birth to an otherwise lightweight lamb(s)], and secondly, the ewe must have the means to respond (i.e. an adequate level of maternal reserves and/or level of nutrition to partition towards additional fetal growth).

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Effect of maternal sleep in late pregnancy on leptin and lipid levels in umbilical cord blood

Sleep Medicine ◽

10.1016/j.sleep.2019.11.1194 ◽

2019 ◽

Author(s):

Min Meng ◽

Yanrui Jiang ◽

Lixia Zhu ◽

Guanghai Wang ◽

Qingmin Lin ◽

...

Keyword(s):

Cord Blood ◽

Umbilical Cord ◽

Umbilical Cord Blood ◽

Late Pregnancy ◽

Lipid Levels ◽

Maternal Sleep

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A postal survey of maternal sleep in late pregnancy

BMC Pregnancy and Childbirth ◽

10.1186/1471-2393-12-144 ◽

2012 ◽

Vol 12 (1) ◽

Cited By ~ 54

Author(s):

B Lynne Hutchison ◽

Peter R Stone ◽

Lesley ME McCowan ◽

Alistair W Stewart ◽

John MD Thompson ◽

...

Keyword(s):

Late Pregnancy ◽

Postal Survey ◽

Maternal Sleep

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The effect of two feeding patterns on performance of bred doe kids in late pregnancy

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600022029 ◽

1992 ◽

Vol 1992 ◽

pp. 91-91

Author(s):

S Scanlan ◽

L C Roger

Keyword(s):

New Zealand ◽

Late Pregnancy ◽

Breeding Programme ◽

Early Age ◽

Genetic Progress ◽

Feeding Patterns ◽

Flat Rate ◽

Subsequent Performance ◽

Complete Diet

Breeding does at an early age can accelerate genetic progress in a breeding programme. However there is little information on the management and nutrition of bred doe kids. This trial investigated flat rate and stepped rate allocations of energy during the last 9 weeks pre-kidding and the effects of these treatments on the subsequent performance of both does and kids.In December 1990 42 first and second cross cashmere doe kids were selected for breeding on the basis of liveweight (minimum 18.5 kg) and housed until kidding in early May. Two 3 year old New Zealand bucks were run with them for 4 weeks. A complete diet, consisting of grass nuts and maize gluten was fed during the housing period.

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Modification of maternal late pregnancy sleep position: a survey evaluation of a New Zealand public health campaign

BMJ Open ◽

10.1136/bmjopen-2020-047681 ◽

2021 ◽

Vol 11 (5) ◽

pp. e047681

Author(s):

Robin S Cronin ◽

John M D Thompson ◽

Rennae S Taylor ◽

Jessica Wilson ◽

Karen F Falloon ◽

...

Keyword(s):

Public Health ◽

New Zealand ◽

Pregnant Women ◽

Supine Position ◽

Health Professionals ◽

Primary Outcome ◽

Late Pregnancy ◽

Sleep Position ◽

Public Health Campaign ◽

Health Campaign

IntroductionA ‘Sleep-On-Side When Baby’s Inside’ public health campaign was initiated in New Zealand in 2018. This was in response to evidence that maternal supine going-to-sleep position was an independent risk factor for stillbirth from 28 weeks’ gestation. We evaluated the success of the campaign on awareness and modification of late pregnancy going-to-sleep position through nationwide surveys.Methods and analysisTwo web-based cross-sectional surveys were conducted over 12 weeks in 2019–2020 in a sample of (1) pregnant women ≥28 weeks, primary outcome of going-to-sleep position; and (2) health professionals providing pregnancy care, primary outcome of knowledge of going-to-sleep position and late stillbirth risk. Univariable logistic regression was performed to identify factors associated with supine going-to-sleep position.DiscussionThe survey of pregnant women comprised 1633 eligible participants. Going-to-sleep position last night was supine (30, 1.8%), non-supine (1597, 97.2%) and no recall (16, 1.0%). Supine position had decreased from 3.9% in our previous New Zealand-wide study (2012–2015). Most women (1412, 86.5%) had received sleep-on-side advice with no major resultant worry (1276, 90.4%). Two-thirds (918, 65.0%) had changed their going-to-sleep position based on advice, with most (611 of 918, 66.5%) reporting little difficulty. Supine position was associated with Māori (OR 5.05, 95% CI 2.10 to 12.1) and Asian-non-Indian (OR 4.20, 95% CI 1.27 to 13.90) ethnicity; single (OR 10.98, 95% CI 4.25 to 28.42) and cohabitating relationship status (OR 2.69, 95% CI 1.09 to 6.61); hospital-based maternity provider (OR 2.55, 95% CI 1.07 to 6.10); education overseas (OR 3.92, 95% CI 1.09 to 14.09) and primary-secondary level (OR 2.80, 95% CI 1.32 to 6.08); and not receiving sleep-on-side advice (OR 6.70, 95% CI 3.23 to 13.92). The majority of health professionals (709 eligible participants) reported awareness of supine going-to-sleep position and late stillbirth risk (543, 76.6%).ConclusionMost pregnant women had received and implemented sleep-on-side advice without major difficulty or concern. Some groups of women may need a tailored approach to acquisition of going-to-sleep position information.

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Going to sleep in the supine position is a modifiable risk factor for late pregnancy stillbirth; Findings from the New Zealand multicentre stillbirth case-control study

PLoS ONE ◽

10.1371/journal.pone.0179396 ◽

2017 ◽

Vol 12 (6) ◽

pp. e0179396 ◽

Cited By ~ 42

Author(s):

Lesley M. E. McCowan ◽

John M. D. Thompson ◽

Robin S. Cronin ◽

Minglan Li ◽

Tomasina Stacey ◽

...

Keyword(s):

Risk Factor ◽

New Zealand ◽

Supine Position ◽

Case Control Study ◽

Late Pregnancy ◽

Case Control ◽

Modifiable Risk Factor ◽

Control Study

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Translocation from flowering to daughter tillers in perennial ryegrass (Lolium perenne L.)

Australian Journal of Agricultural Research ◽

10.1071/ar00082 ◽

2002 ◽

Vol 53 (1) ◽

pp. 21 ◽

Cited By ~ 4

Author(s):

C. Matthew

Keyword(s):

New Zealand ◽

Birth Weight ◽

Lolium Perenne ◽

Late Pregnancy ◽

Early Summer ◽

High Rate ◽

Lolium Perenne L ◽

Feeding Level ◽

High Level ◽

Summit Metabolic Rate

Recent New Zealand cultivars of Lolium perenne often have a high rate of tiller death and replacement in late spring–early summer. A majority of the new tillers are daughter tillers of flowering tillers. Previous research has led to a hypothesis that defoliation may influence the amount of assimilate exported by flowering tillers, and hence the rate of daughter tiller formation. To test this hypothesis, flowering tillers of of nutrition that enabled the dam to gain 100 g/day of conceptus-free liveweight in addition to expected fetal growth) during the mid pregnancy (post-shearing) period (from Day 70 of pregnancy (P70) until P101). At the end of this period ewes were offered either maintenance or a high level of nutrition during late pregnancy (P102–P140). Pregnancy shearing was found to increase lamb birthweight (average birthweight 5.4±0.1 v. 5.1± 0.1 kg) without differentially affecting the birthweight of singles or twins. Dam feeding level post-shearing did not affect the birthweight response to mid pregnancy shearing. Pregnancy shearing treatment had no effect on the summit metabolic rate of twin lambs. However, when results of this study are compiled with those of previous mid to late pregnancy shearing studies under similar conditions, it appears that the birth weight response from pregnancy shearing is greatest where lightweight lambs are born to unshorn (control) ewes.

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